PATENT DOCUMENT

Publication Number: US-10999426-B2
Application Number: US-201916667269-A
Country: US
Kind Code: B2

Title: Voice communication method

Abstract:
An electronic device is disclosed. The electronic device includes one or more processors and memory storing one or more programs configured to be executed by the one or more processors. The one or more programs include instructions for receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device; determining whether the contact is on a list; and in response to a determination that the contact is on the list, establishing the full-duplex live audio communication session between the electronic device and the external device, where the live audio communication session is established without receiving a user input that acknowledges the request.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 one or more processors; and 
 memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for:
 receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device; and 
 in accordance with a determination that the contact is on a list, establishing the full-duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request. 
 
 
     
     
       2. The electronic device of  claim 1 , wherein the one or more programs further include instructions for:
 in accordance with a determination that the contact is not on the list, establishing the full-duplex live audio communication session only if the user input is detected. 
 
     
     
       3. The electronic device of  claim 1 , wherein the one or more programs further include instructions for:
 in accordance with a determination that the contact is not on the list, waiting for a user input that accepts the request. 
 
     
     
       4. The electronic device of  claim 1 , further including a microphone, and wherein the one or more programs further include instructions for:
 in response to establishing the full-duplex live audio communication session, disabling audio input to the microphone. 
 
     
     
       5. The electronic device of  claim 1 , wherein the one or more programs further include instructions for:
 in response to receiving a second user input, sending a second request to establish a second full-duplex live audio communication session between the electronic device and a second external device associated with a second contact; and 
 in response to sending the second request to the second external device, adding the second contact to the list. 
 
     
     
       6. A method, comprising:
 at an electronic device:
 receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device; and 
 in response to a determination that the contact is on a list, establishing the full-duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request. 
 
 
     
     
       7. The method of  claim 6 , further comprising:
 in accordance with a determination that the contact is not on the list, establishing the full-duplex live audio communication session only if the user input is detected. 
 
     
     
       8. The method of  claim 6 , further comprising:
 in accordance with a determination that the contact is not on the list, waiting for a user input that accepts the request. 
 
     
     
       9. The method of  claim 6 , wherein the electronic device includes a microphone; and
 wherein the method further comprises: 
 in response to establishing the full-duplex live audio communication session, disabling audio input to the microphone. 
 
     
     
       10. The method of  claim 6 , further comprising:
 in response to receiving a second user input, sending a second request to establish a second full-duplex live audio communication session between the electronic device and a second external device associated with a second contact; and 
 in response to sending the second request to the second external device, adding the second contact to the list. 
 
     
     
       11. A non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device, the one or more programs including instructions for:
 receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device; and 
 in response to a determination that the contact is on a list, establishing the full-duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request. 
 
     
     
       12. The non-transitory computer-readable storage medium of  claim 11 , wherein the one or more programs further include instructions for:
 in accordance with a determination that the contact is not on the list, establishing the full-duplex live audio communication session only if the user input is detected. 
 
     
     
       13. The non-transitory computer-readable storage medium of  claim 11 , wherein the one or more programs further include instructions for:
 in accordance with a determination that the contact is not on the list, waiting for a user input that accepts the request. 
 
     
     
       14. The non-transitory computer-readable storage medium of  claim 11 , wherein the electronic device further includes a microphone, and wherein the one or more programs further include instructions for:
 in response to establishing the full-duplex live audio communication session, disabling audio input to the microphone. 
 
     
     
       15. The non-transitory computer-readable storage medium of  claim 11 , wherein the one or more programs further include instructions for:
 in response to receiving a second user input, sending a second request to establish a second full-duplex live audio communication session between the electronic device and a second external device associated with a second contact; and 
 in response to sending the second request to the second external device, adding the second contact to the list.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 15/719,344, entitled “VOICE COMMUNICATION METHOD,” filed on Sep. 28, 2017, which claims priority to U.S. Provisional Patent Application No. 62/507,167, entitled “VOICE COMMUNICATION METHOD,” filed on May 16, 2017 and U.S. Provisional Patent Application No. 62/507,195, entitled “VOICE COMMUNICATION METHOD,” filed on May 16, 2017, the contents of which are hereby incorporated by reference in their entireties. 
    
    
     FIELD 
     The present disclosure relates generally to electronic communications, and more specifically to computer user interfaces and techniques for electronic voice communications. 
     BACKGROUND 
     Electronic devices can provide various forms of communication for their users. For example, some electronic devices can provide voice communications such as phone calls, video calls, and recorded messages such as voicemail. 
     BRIEF SUMMARY 
     Some techniques for communicating with others using electronic devices, however, are generally cumbersome and inefficient. For example, some existing techniques use a complex and time-consuming user interface, which may include multiple key presses or keystrokes. Existing techniques require more time than necessary, wasting user time and device energy. This latter consideration is particularly important in battery-operated devices. 
     Accordingly, the present technique provides electronic devices with faster, more efficient methods and interfaces for electronic communications, such as voice communications. Such methods and interfaces optionally complement or replace other methods for communication. Such methods and interfaces reduce the cognitive burden on a user and produce a more efficient human-machine interface, for example by reducing or eliminating a number of unnecessary, extraneous, and repetitive inputs at the device. For battery-operated computing devices, such methods and interfaces conserve power and increase the time between battery charges. For example, the methods and interfaces contemplated herein offer reduced processing power, reduced memory usage, and reduced battery usage by a display at the device. 
     Example devices are disclosed herein. An example electronic device includes a speaker, one or more processors, and memory storing one or more programs configured to be executed by the one or more processors. The one or more programs include instructions for, while in a full-duplex live audio communication session with an external device, the full-duplex live audio communication session configured to transmit control signal data and separately transmit audio data: receiving control signal data from the external device, in response to receiving the control signal data, issuing a perceptual notification, after a first predetermined time period since receiving the control signal data, receiving audio data from the external device, and after a second predetermined time period since issuing the perceptual notification, outputting the audio data from the speaker. 
     An example electronic device includes one or more processors and memory storing one or more programs configured to be executed by the one or more processors. The one or more programs include instructions for, receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device, determining whether the contact is on a list, and, in response to a determination that the contact is on the list, establishing the full-duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request. 
     Example methods are disclosed herein. An example method includes, at electronic device with a speaker, while in a full-duplex live audio communication session with an external device, the full-duplex live audio communication session configured to transmit control signal data and separately transmit audio data, receiving control signal data from the external device, in response to receiving the control signal data, issuing a perceptual notification, after a first predetermined time period since receiving the control signal data, receiving audio data from the external device, and after a second predetermined time period since issuing the perceptual notification, outputting the audio data from the speaker 
     An example method includes, at an electronic device, receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device. The one or more programs include instructions for determining whether the contact is on a list. The one or more programs include instructions for, in response to a determination that the contact is on the list, establishing the full-duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request. 
     Example non-transitory computer-readable storage media are disclosed herein. An example non-transitory computer-readable storage medium stores one or more programs configured to executed by one or more processors of an electronic device, the one or more programs including instructions for: while in a full-duplex live audio communication session with an external device, the full-duplex live audio communication session configured to transmit control signal data and separately transmit audio data: receiving control signal data from the external device, in response to receiving the control signal data, issuing a perceptual notification, after a first predetermined time period since receiving the control signal data, receiving audio data from the external device, and after a second predetermined time period since issuing the perceptual notification, outputting the audio data from the speaker. 
     Example non-transitory computer-readable storage media are disclosed herein. An example non-transitory computer-readable storage medium stores one or more programs configured to executed by one or more processors of an electronic device, the one or more programs including instructions for receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device. The one or more programs include instructions for determining whether the contact is on a list. The one or more programs include instructions for, in response to a determination that the contact is on the list, establishing the full-duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request. 
     Executable instructions for performing these functions are, optionally, included in a non-transitory computer-readable storage medium or other computer program product configured for execution by one or more processors. Executable instructions for performing these functions are, optionally, included in a transitory computer-readable storage medium or other computer program product configured for execution by one or more processors. 
     Thus, devices are provided with faster, more efficient methods and interfaces for electronic voice communications, thereby increasing the effectiveness, efficiency, and user satisfaction with such devices. Such methods and interfaces may complement or replace other methods for communication. 
    
    
     
       DESCRIPTION OF THE FIGURES 
       For a better understanding of the various described embodiments, reference should be made to the Description of Embodiments below, in conjunction with the following drawings in which like reference numerals refer to corresponding parts throughout the figures. 
         FIG. 1A  is a block diagram illustrating a portable multifunction device with a touch-sensitive display in accordance with some embodiments. 
         FIG. 1B  is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. 
         FIG. 2  illustrates a portable multifunction device having a touch screen in accordance with some embodiments. 
         FIG. 3  is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface in accordance with some embodiments. 
         FIG. 4A  illustrates an exemplary user interface for a menu of applications on a portable multifunction device in accordance with some embodiments. 
         FIG. 4B  illustrates an exemplary user interface for a multifunction device with a touch-sensitive surface that is separate from the display in accordance with some embodiments. 
         FIG. 5A  illustrates a personal electronic device in accordance with some embodiments. 
         FIG. 5B  is a block diagram illustrating a personal electronic device in accordance with some embodiments. 
         FIGS. 6AA to 6AI  illustrate exemplary techniques and user interfaces for electronic voice communications, including sending and receiving voice communications, in accordance with some embodiments. 
         FIGS. 6BA to 6BD  illustrate exemplary techniques and user interfaces for electronic voice communications, including preventing audio output of incoming voice data, in accordance with some embodiments. 
         FIGS. 6CA to 6CE  illustrate exemplary techniques and user interfaces for electronic voice communications, including interrupting audio output of incoming voice data, in accordance with some embodiments. 
         FIGS. 6DA to 6DE  illustrate exemplary techniques and user interfaces for electronic voice communications, including toggling a do-not-disturb mode, in accordance with some embodiments. 
         FIGS. 6EA to 6EB  illustrate exemplary techniques and user interfaces for electronic voice communications, including handling incoming notifications during voice communications, in accordance with some embodiments. 
         FIGS. 6FA to 6FF  illustrate exemplary techniques and user interfaces for electronic voice communications, including another example for handling incoming notifications during voice communications, in accordance with some embodiments. 
         FIGS. 6GA to 6GF  illustrate exemplary techniques and user interfaces for electronic voice communications, including yet another example for handling incoming notifications during voice communications, in accordance with some embodiments. 
         FIGS. 6HA to 6HH  illustrate exemplary techniques and user interfaces for electronic voice communications, including further examples for handling incoming notifications during voice communications, in accordance with some embodiments. 
         FIGS. 61A to 6IC  illustrate exemplary techniques and user interfaces for electronic voice communications, including examples of user unavailability during voice communications, in accordance with some embodiments. 
         FIGS. 6JA to 6JK  illustrate exemplary techniques and user interfaces for electronic voice communications, including examples for connecting to a new contact, in accordance with some embodiments. 
         FIGS. 6KA to 6KN  illustrate exemplary techniques and user interfaces for electronic voice communications, including an example for handling invitations and connecting to new contacts, in accordance with some embodiments. 
         FIGS. 6LA to 6LD  illustrate exemplary techniques and user interfaces for electronic voice communications, including further examples for handling invitations and connecting to new contacts, in accordance with some embodiments. 
         FIGS. 6MA to 6MC  illustrate exemplary techniques and user interfaces for electronic voice communications, including another example for handling invitations and connecting to new contacts, in accordance with some embodiments. 
         FIGS. 6NA to 6NF  illustrate exemplary techniques and user interfaces for electronic voice communications, including further examples for handling invitations and connecting to new contacts, in accordance with some embodiments. 
         FIGS. 6OA to 6OH  illustrate exemplary techniques and user interfaces for electronic voice communications, including examples of when a contact is unavailable, in accordance with some embodiments. 
         FIGS. 7AA to 7AI  illustrate exemplary techniques and user interfaces for electronic voice communications, including switching between different contacts, in accordance with some embodiments. 
         FIGS. 7BA to 7BH  illustrate exemplary techniques and user interfaces for electronic voice communications, including switching between different contacts, in accordance with some embodiments. 
         FIGS. 7CA to 7CH  illustrate exemplary techniques and user interfaces for electronic voice communications, including further examples for switching between different contacts, in accordance with some embodiments. 
         FIGS. 7DA to 7DD  illustrate exemplary techniques and user interfaces for electronic voice communications, including still further examples for switching between different contacts, in accordance with some embodiments. 
         FIGS. 7EA to 7ED  illustrate exemplary techniques and user interfaces for electronic voice communications, including more examples for switching between different contacts, in accordance with some embodiments. 
         FIGS. 8A-8X  illustrate exemplary techniques and user interfaces for electronic voice communications, including a first time user setup for voice communications, in accordance with some embodiments. 
         FIG. 9  is a flow diagram illustrating an example method for electronic voice communications, including sending and receiving voice communications, in accordance with some embodiments. 
         FIG. 10  is a flow diagram illustrating an example method for electronic voice communications, including switching between voice communications with different contacts, in accordance with some embodiments. 
         FIG. 11  is a flow diagram illustrating an example method for electronic voice communications, including establishing voice communications with new contacts, in accordance with some embodiments. 
         FIG. 12  is a flow diagram illustrating an example method for electronic voice communications, including receiving control signal data and audio data, in accordance with some embodiments. 
         FIG. 13  is a flow diagram illustrating an example method for electronic voice communications, including establishing a live audio communication session, in accordance with some embodiments. 
         FIG. 14A  illustrates a diagram of different states and state transitions of a receiver device for electronic voice communications, in accordance with some embodiments. 
         FIG. 14B  illustrates a diagram of different states and state transitions of a caller device for electronic voice communications, in accordance with some embodiments. 
         FIG. 15  illustrates receiving of control signal data on a first channel and receiving of audio data on a second channel during electronic voice communications, in accordance with some embodiments. 
         FIG. 16  illustrates transmitting control signal data on a first channel and transmitting audio data on a second channel during electronic voice communications, in accordance with some embodiments. 
         FIG. 17  illustrates an example wireless communication system in which an electronic device communicates with a network using two different channels, in accordance with some embodiments. 
         FIG. 18  illustrates two communication paths between an electronic device and an external device that is paired with a companion device, in accordance with some embodiments. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following description sets forth exemplary methods, parameters, and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure but is instead provided as a description of exemplary embodiments. 
     There is a need for electronic devices that provide efficient methods and interfaces for communications, such as voice communications. Current techniques may require additional user inputs. Such techniques can reduce the cognitive burden on a user communicating with another user at another electronic device, thereby enhancing productivity. Further, such techniques can reduce processor and battery power otherwise wasted on redundant user inputs. 
     Below,  FIGS. 1A-1B, 2, 3, 4A-4B, and 5A-5B  provide a description of exemplary devices for performing the techniques for voice communications. In general, the set of  FIGS. 6AA to 6AI  through the set of  FIGS. 6OA to 6OH  illustrate exemplary techniques and user interfaces for voice communications.  FIGS. 9 and 11  are flow diagrams illustrating methods for voice communications in accordance with some embodiments. The user interfaces in the set of  FIGS. 6AA to 6AI  through the set of  FIGS. 6OA to 6OH  are used to illustrate the processes described below, including the processes in  FIGS. 9 and 11 . The set of  FIGS. 7AA to 7AI  through the set of  FIGS. 7EA to 7ED  illustrate exemplary techniques and user interfaces for voice communications, including switching between contacts.  FIG. 10  is a flow diagram illustrating methods for voice communications in accordance with some embodiments. The user interfaces in  FIGS. 7AA to 7AI  through the set of  FIGS. 7EA to 7ED  are used to illustrate the processes described below, including the processes in  FIG. 10 .  FIGS. 8A-8X  illustrate exemplary user interfaces for voice communications.  FIG. 11  is a flow diagram illustrating methods of voice communications in accordance with some embodiments. The user interfaces in  FIGS. 8A-8X  are used to illustrate the processes described below, including the processes in  FIG. 11 .  FIG. 12  is a flow diagram describing voice communication methods that include receiving control signal data and audio data.  FIG. 13  is a flow diagram describing voice communication methods that include establishing live audio communication sessions.  FIGS. 14A, 14B, 15, and 16  are used to further illustrate these techniques (including the processes depicted in  FIGS. 9, 10, 11, 13, and 14 ) in accordance with some embodiments.  FIG. 17  illustrates an exemplary wireless communication network for use in the voice communication methods of  FIGS. 9, 10, 11, 13, and 14 .  FIG. 18  illustrates communication paths that include a companion device for use in the voice communication methods of  FIGS. 9, 10, 11, 13, and 14 . 
     Although the following description uses terms “first,” “second,” etc. to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another. For example, a first touch could be termed a second touch, and, similarly, a second touch could be termed a first touch, without departing from the scope of the various described embodiments. The first touch and the second touch are both touches, but they are not the same touch. 
     The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various described embodiments and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     The term “if” is, optionally, construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. Similarly, the phrase “if it is determined” or “if [a stated condition or event] is detected” is, optionally, construed to mean “upon determining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event],” depending on the context. 
     Embodiments of electronic devices, user interfaces for such devices, and associated processes for using such devices are described. In some embodiments, the device is a portable communications device, such as a mobile telephone, that also contains other functions, such as PDA and/or music player functions. Exemplary embodiments of portable multifunction devices include, without limitation, the iPhone®, iPod Touch®, and iPad® devices from Apple Inc. of Cupertino, Calif. Other portable electronic devices, such as laptops or tablet computers with touch-sensitive surfaces (e.g., touch screen displays and/or touchpads), are, optionally, used. It should also be understood that, in some embodiments, the device is not a portable communications device, but is a desktop computer with a touch-sensitive surface (e.g., a touch screen display and/or a touchpad). 
     In the discussion that follows, an electronic device that includes a display and a touch-sensitive surface is described. It should be understood, however, that the electronic device optionally includes one or more other physical user-interface devices, such as a physical keyboard, a mouse, and/or a joystick. 
     The device typically supports a variety of applications, such as one or more of the following: a drawing application, a presentation application, a word processing application, a website creation application, a disk authoring application, a spreadsheet application, a gaming application, a telephone application, a video conferencing application, an e-mail application, an instant messaging application, a workout support application, a photo management application, a digital camera application, a digital video camera application, a web browsing application, a digital music player application, and/or a digital video player application. 
     The various applications that are executed on the device optionally use at least one common physical user-interface device, such as the touch-sensitive surface. One or more functions of the touch-sensitive surface as well as corresponding information displayed on the device are, optionally, adjusted and/or varied from one application to the next and/or within a respective application. In this way, a common physical architecture (such as the touch-sensitive surface) of the device optionally supports the variety of applications with user interfaces that are intuitive and transparent to the user. 
     Attention is now directed toward embodiments of portable devices with touch-sensitive displays.  FIG. 1A  is a block diagram illustrating portable multifunction device  100  with touch-sensitive display system  112  in accordance with some embodiments. Touch-sensitive display  112  is sometimes called a “touch screen” for convenience and is sometimes known as or called a “touch-sensitive display system.” Device  100  includes memory  102  (which optionally includes one or more computer-readable storage mediums), memory controller  122 , one or more processing units (CPUs)  120 , peripherals interface  118 , RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , input/output (I/O) subsystem  106 , other input control devices  116 , and external port  124 . Device  100  optionally includes one or more optical sensors  164 . Device  100  optionally includes one or more contact intensity sensors  165  for detecting intensity of contacts on device  100  (e.g., a touch-sensitive surface such as touch-sensitive display system  112  of device  100 ). Device  100  optionally includes one or more tactile output generators  167  for generating tactile outputs on device  100  (e.g., generating tactile outputs on a touch-sensitive surface such as touch-sensitive display system  112  of device  100  or touchpad  355  of device  300 ). These components optionally communicate over one or more communication buses or signal lines  103 . 
     As used in the specification and claims, the term “intensity” of a contact on a touch-sensitive surface refers to the force or pressure (force per unit area) of a contact (e.g., a finger contact) on the touch-sensitive surface, or to a substitute (proxy) for the force or pressure of a contact on the touch-sensitive surface. The intensity of a contact has a range of values that includes at least four distinct values and more typically includes hundreds of distinct values (e.g., at least 256). Intensity of a contact is, optionally, determined (or measured) using various approaches and various sensors or combinations of sensors. For example, one or more force sensors underneath or adjacent to the touch-sensitive surface are, optionally, used to measure force at various points on the touch-sensitive surface. In some implementations, force measurements from multiple force sensors are combined (e.g., a weighted average) to determine an estimated force of a contact. Similarly, a pressure-sensitive tip of a stylus is, optionally, used to determine a pressure of the stylus on the touch-sensitive surface. Alternatively, the size of the contact area detected on the touch-sensitive surface and/or changes thereto, the capacitance of the touch-sensitive surface proximate to the contact and/or changes thereto, and/or the resistance of the touch-sensitive surface proximate to the contact and/or changes thereto are, optionally, used as a substitute for the force or pressure of the contact on the touch-sensitive surface. In some implementations, the substitute measurements for contact force or pressure are used directly to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is described in units corresponding to the substitute measurements). In some implementations, the substitute measurements for contact force or pressure are converted to an estimated force or pressure, and the estimated force or pressure is used to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is a pressure threshold measured in units of pressure). Using the intensity of a contact as an attribute of a user input allows for user access to additional device functionality that may otherwise not be accessible by the user on a reduced-size device with limited real estate for displaying affordances (e.g., on a touch-sensitive display) and/or receiving user input (e.g., via a touch-sensitive display, a touch-sensitive surface, or a physical/mechanical control such as a knob or a button). 
     As used in the specification and claims, the term “tactile output” refers to physical displacement of a device relative to a previous position of the device, physical displacement of a component (e.g., a touch-sensitive surface) of a device relative to another component (e.g., housing) of the device, or displacement of the component relative to a center of mass of the device that will be detected by a user with the user&#39;s sense of touch. For example, in situations where the device or the component of the device is in contact with a surface of a user that is sensitive to touch (e.g., a finger, palm, or other part of a user&#39;s hand), the tactile output generated by the physical displacement will be interpreted by the user as a tactile sensation corresponding to a perceived change in physical characteristics of the device or the component of the device. For example, movement of a touch-sensitive surface (e.g., a touch-sensitive display or trackpad) is, optionally, interpreted by the user as a “down click” or “up click” of a physical actuator button. In some cases, a user will feel a tactile sensation such as an “down click” or “up click” even when there is no movement of a physical actuator button associated with the touch-sensitive surface that is physically pressed (e.g., displaced) by the user&#39;s movements. As another example, movement of the touch-sensitive surface is, optionally, interpreted or sensed by the user as “roughness” of the touch-sensitive surface, even when there is no change in smoothness of the touch-sensitive surface. While such interpretations of touch by a user will be subject to the individualized sensory perceptions of the user, there are many sensory perceptions of touch that are common to a large majority of users. Thus, when a tactile output is described as corresponding to a particular sensory perception of a user (e.g., an “up click,” a “down click,” “roughness”), unless otherwise stated, the generated tactile output corresponds to physical displacement of the device or a component thereof that will generate the described sensory perception for a typical (or average) user. 
     It should be appreciated that device  100  is only one example of a portable multifunction device, and that device  100  optionally has more or fewer components than shown, optionally combines two or more components, or optionally has a different configuration or arrangement of the components. The various components shown in  FIG. 1A  are implemented in hardware, software, or a combination of both hardware and software, including one or more signal processing and/or application-specific integrated circuits. 
     Memory  102  optionally includes high-speed random access memory and optionally also includes non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices. Memory controller  122  optionally controls access to memory  102  by other components of device  100 . 
     Peripherals interface  118  can be used to couple input and output peripherals of the device to CPU  120  and memory  102 . The one or more processors  120  run or execute various software programs and/or sets of instructions stored in memory  102  to perform various functions for device  100  and to process data. In some embodiments, peripherals interface  118 , CPU  120 , and memory controller  122  are, optionally, implemented on a single chip, such as chip  104 . In some other embodiments, they are, optionally, implemented on separate chips. 
     RF (radio frequency) circuitry  108  receives and sends RF signals, also called electromagnetic signals. RF circuitry  108  converts electrical signals to/from electromagnetic signals and communicates with communications networks and other communications devices via the electromagnetic signals. RF circuitry  108  optionally includes well-known circuitry for performing these functions, including but not limited to an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC chipset, a subscriber identity module (SIM) card, memory, and so forth. RF circuitry  108  optionally communicates with networks, such as the Internet, also referred to as the World Wide Web (WWW), an intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN), and other devices by wireless communication. The RF circuitry  108  optionally includes well-known circuitry for detecting near field communication (NFC) fields, such as by a short-range communication radio. The wireless communication optionally uses any of a plurality of communications standards, protocols, and technologies, including but not limited to Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), high-speed downlink packet access (HSDPA), high-speed uplink packet access (HSUPA), Evolution, Data-Only (EV-DO), HSPA, HSPA+, Dual-Cell HSPA (DC-HSPDA), long term evolution (LTE), near field communication (NFC), wideband code division multiple access (W-CDMA), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Bluetooth Low Energy (BTLE), Wireless Fidelity (Wi-Fi) (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, and/or IEEE 802.11ac), voice over Internet Protocol (VoIP), Wi-MAX, a protocol for e-mail (e.g., Internet message access protocol (IMAP) and/or post office protocol (POP)), instant messaging (e.g., extensible messaging and presence protocol (XMPP), Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions (SIMPLE), Instant Messaging and Presence Service (IMPS)), and/or Short Message Service (SMS), or any other suitable communication protocol, including communication protocols not yet developed as of the filing date of this document. 
     Audio circuitry  110 , speaker  111 , and microphone  113  provide an audio interface between a user and device  100 . Audio circuitry  110  receives audio data from peripherals interface  118 , converts the audio data to an electrical signal, and transmits the electrical signal to speaker  111 . Speaker  111  converts the electrical signal to human-audible sound waves. Audio circuitry  110  also receives electrical signals converted by microphone  113  from sound waves. Audio circuitry  110  converts the electrical signal to audio data and transmits the audio data to peripherals interface  118  for processing. Audio data is, optionally, retrieved from and/or transmitted to memory  102  and/or RF circuitry  108  by peripherals interface  118 . In some embodiments, audio circuitry  110  also includes a headset jack (e.g.,  212 ,  FIG. 2 ). The headset jack provides an interface between audio circuitry  110  and removable audio input/output peripherals, such as output-only headphones or a headset with both output (e.g., a headphone for one or both ears) and input (e.g., a microphone). 
     I/O subsystem  106  couples input/output peripherals on device  100 , such as touch screen  112  and other input control devices  116 , to peripherals interface  118 . I/O subsystem  106  optionally includes display controller  156 , optical sensor controller  158 , intensity sensor controller  159 , haptic feedback controller  161 , and one or more input controllers  160  for other input or control devices. The one or more input controllers  160  receive/send electrical signals from/to other input control devices  116 . The other input control devices  116  optionally include physical buttons (e.g., push buttons, rocker buttons, etc.), dials, slider switches, joysticks, click wheels, and so forth. In some alternate embodiments, input controller(s)  160  are, optionally, coupled to any (or none) of the following: a keyboard, an infrared port, a USB port, and a pointer device such as a mouse. The one or more buttons (e.g.,  208 ,  FIG. 2 ) optionally include an up/down button for volume control of speaker  111  and/or microphone  113 . The one or more buttons optionally include a push button (e.g.,  206 ,  FIG. 2 ). 
     A quick press of the push button optionally disengages a lock of touch screen  112  or optionally begins a process that uses gestures on the touch screen to unlock the device, as described in U.S. patent application Ser. No. 11/322,549, “Unlocking a Device by Performing Gestures on an Unlock Image,” filed Dec. 23, 2005, U.S. Pat. No. 7,657,849, which is hereby incorporated by reference in its entirety. A longer press of the push button (e.g.,  206 ) optionally turns power to device  100  on or off. The functionality of one or more of the buttons are, optionally, user-customizable. Touch screen  112  is used to implement virtual or soft buttons and one or more soft keyboards. 
     Touch-sensitive display  112  provides an input interface and an output interface between the device and a user. Display controller  156  receives and/or sends electrical signals from/to touch screen  112 . Touch screen  112  displays visual output to the user. The visual output optionally includes graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). In some embodiments, some or all of the visual output optionally corresponds to user-interface objects. 
     Touch screen  112  has a touch-sensitive surface, sensor, or set of sensors that accepts input from the user based on haptic and/or tactile contact. Touch screen  112  and display controller  156  (along with any associated modules and/or sets of instructions in memory  102 ) detect contact (and any movement or breaking of the contact) on touch screen  112  and convert the detected contact into interaction with user-interface objects (e.g., one or more soft keys, icons, web pages, or images) that are displayed on touch screen  112 . In an exemplary embodiment, a point of contact between touch screen  112  and the user corresponds to a finger of the user. 
     Touch screen  112  optionally uses LCD (liquid crystal display) technology, LPD (light emitting polymer display) technology, or LED (light emitting diode) technology, although other display technologies are used in other embodiments. Touch screen  112  and display controller  156  optionally detect contact and any movement or breaking thereof using any of a plurality of touch sensing technologies now known or later developed, including but not limited to capacitive, resistive, infrared, and surface acoustic wave technologies, as well as other proximity sensor arrays or other elements for determining one or more points of contact with touch screen  112 . In an exemplary embodiment, projected mutual capacitance sensing technology is used, such as that found in the iPhone® and iPod Touch® from Apple Inc. of Cupertino, Calif. 
     A touch-sensitive display in some embodiments of touch screen  112  is, optionally, analogous to the multi-touch sensitive touchpads described in the following U.S. Pat. No. 6,323,846 (Westerman et al.), U.S. Pat. No. 6,570,557 (Westerman et al.), and/or U.S. Pat. No. 6,677,932 (Westerman), and/or U.S. Patent Publication 2002/0015024A1, each of which is hereby incorporated by reference in its entirety. However, touch screen  112  displays visual output from device  100 , whereas touch-sensitive touchpads do not provide visual output. 
     A touch-sensitive display in some embodiments of touch screen  112  is described in the following applications: (1) U.S. patent application Ser. No. 11/381,313, “Multipoint Touch Surface Controller,” filed May 2, 2006; (2) U.S. patent application Ser. No. 10/840,862, “Multipoint Touchscreen,” filed May 6, 2004; (3) U.S. patent application Ser. No. 10/903,964, “Gestures For Touch Sensitive Input Devices,” filed Jul. 30, 2004; (4) U.S. patent application Ser. No. 11/048,264, “Gestures For Touch Sensitive Input Devices,” filed Jan. 31, 2005; (5) U.S. patent application Ser. No. 11/038,590, “Mode-Based Graphical User Interfaces For Touch Sensitive Input Devices,” filed Jan. 18, 2005; (6) U.S. patent application Ser. No. 11/228,758, “Virtual Input Device Placement On A Touch Screen User Interface,” filed Sep. 16, 2005; (7) U.S. patent application Ser. No. 11/228,700, “Operation Of A Computer With A Touch Screen Interface,” filed Sep. 16, 2005; (8) U.S. patent application Ser. No. 11/228,737, “Activating Virtual Keys Of A Touch-Screen Virtual Keyboard,” filed Sep. 16, 2005; and (9) U.S. patent application Ser. No. 11/367,749, “Multi-Functional Hand-Held Device,” filed Mar. 3, 2006. All of these applications are incorporated by reference herein in their entirety. 
     Touch screen  112  optionally has a video resolution in excess of 100 dpi. In some embodiments, the touch screen has a video resolution of approximately 160 dpi. The user optionally makes contact with touch screen  112  using any suitable object or appendage, such as a stylus, a finger, and so forth. In some embodiments, the user interface is designed to work primarily with finger-based contacts and gestures, which can be less precise than stylus-based input due to the larger area of contact of a finger on the touch screen. In some embodiments, the device translates the rough finger-based input into a precise pointer/cursor position or command for performing the actions desired by the user. 
     In some embodiments, in addition to the touch screen, device  100  optionally includes a touchpad (not shown) for activating or deactivating particular functions. In some embodiments, the touchpad is a touch-sensitive area of the device that, unlike the touch screen, does not display visual output. The touchpad is, optionally, a touch-sensitive surface that is separate from touch screen  112  or an extension of the touch-sensitive surface formed by the touch screen. 
     Device  100  also includes power system  162  for powering the various components. Power system  162  optionally includes a power management system, one or more power sources (e.g., battery, alternating current (AC)), a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator (e.g., a light-emitting diode (LED)) and any other components associated with the generation, management and distribution of power in portable devices. 
     Device  100  optionally also includes one or more optical sensors  164 .  FIG. 1A  shows an optical sensor coupled to optical sensor controller  158  in I/O subsystem  106 . Optical sensor  164  optionally includes charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) phototransistors. Optical sensor  164  receives light from the environment, projected through one or more lenses, and converts the light to data representing an image. In conjunction with imaging module  143  (also called a camera module), optical sensor  164  optionally captures still images or video. In some embodiments, an optical sensor is located on the back of device  100 , opposite touch screen display  112  on the front of the device so that the touch screen display is enabled for use as a viewfinder for still and/or video image acquisition. In some embodiments, an optical sensor is located on the front of the device so that the user&#39;s image is, optionally, obtained for video conferencing while the user views the other video conference participants on the touch screen display. In some embodiments, the position of optical sensor  164  can be changed by the user (e.g., by rotating the lens and the sensor in the device housing) so that a single optical sensor  164  is used along with the touch screen display for both video conferencing and still and/or video image acquisition. 
     Device  100  optionally also includes one or more contact intensity sensors  165 .  FIG. 1A  shows a contact intensity sensor coupled to intensity sensor controller  159  in I/O subsystem  106 . Contact intensity sensor  165  optionally includes one or more piezoresistive strain gauges, capacitive force sensors, electric force sensors, piezoelectric force sensors, optical force sensors, capacitive touch-sensitive surfaces, or other intensity sensors (e.g., sensors used to measure the force (or pressure) of a contact on a touch-sensitive surface). Contact intensity sensor  165  receives contact intensity information (e.g., pressure information or a proxy for pressure information) from the environment. In some embodiments, at least one contact intensity sensor is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system  112 ). In some embodiments, at least one contact intensity sensor is located on the back of device  100 , opposite touch screen display  112 , which is located on the front of device  100 . 
     Device  100  optionally also includes one or more proximity sensors  166 .  FIG. 1A  shows proximity sensor  166  coupled to peripherals interface  118 . Alternately, proximity sensor  166  is, optionally, coupled to input controller  160  in I/O subsystem  106 . Proximity sensor  166  optionally performs as described in U.S. patent application Ser. No. 11/241,839, “Proximity Detector In Handheld Device”; Ser. No. 11/240,788, “Proximity Detector In Handheld Device”; Ser. No. 11/620,702, “Using Ambient Light Sensor To Augment Proximity Sensor Output”; Ser. No. 11/586,862, “Automated Response To And Sensing Of User Activity In Portable Devices”; and Ser. No. 11/638,251, “Methods And Systems For Automatic Configuration Of Peripherals,” which are hereby incorporated by reference in their entirety. In some embodiments, the proximity sensor turns off and disables touch screen  112  when the multifunction device is placed near the user&#39;s ear (e.g., when the user is making a phone call). 
     Device  100  optionally also includes one or more tactile output generators  167 .  FIG. 1A  shows a tactile output generator coupled to haptic feedback controller  161  in I/O subsystem  106 . Tactile output generator  167  optionally includes one or more electroacoustic devices such as speakers or other audio components and/or electromechanical devices that convert energy into linear motion such as a motor, solenoid, electroactive polymer, piezoelectric actuator, electrostatic actuator, or other tactile output generating component (e.g., a component that converts electrical signals into tactile outputs on the device). Contact intensity sensor  165  receives tactile feedback generation instructions from haptic feedback module  133  and generates tactile outputs on device  100  that are capable of being sensed by a user of device  100 . In some embodiments, at least one tactile output generator is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system  112 ) and, optionally, generates a tactile output by moving the touch-sensitive surface vertically (e.g., in/out of a surface of device  100 ) or laterally (e.g., back and forth in the same plane as a surface of device  100 ). In some embodiments, at least one tactile output generator sensor is located on the back of device  100 , opposite touch screen display  112 , which is located on the front of device  100 . 
     Device  100  optionally also includes one or more accelerometers  168 .  FIG. 1A  shows accelerometer  168  coupled to peripherals interface  118 . Alternately, accelerometer  168  is, optionally, coupled to an input controller  160  in I/O subsystem  106 . Accelerometer  168  optionally performs as described in U.S. Patent Publication No. 20050190059, “Acceleration-based Theft Detection System for Portable Electronic Devices,” and U.S. Patent Publication No. 20060017692, “Methods And Apparatuses For Operating A Portable Device Based On An Accelerometer,” both of which are incorporated by reference herein in their entirety. In some embodiments, information is displayed on the touch screen display in a portrait view or a landscape view based on an analysis of data received from the one or more accelerometers. Device  100  optionally includes, in addition to accelerometer(s)  168 , a magnetometer (not shown) and a GPS (or GLONASS or other global navigation system) receiver (not shown) for obtaining information concerning the location and orientation (e.g., portrait or landscape) of device  100 . 
     In some embodiments, the software components stored in memory  102  include operating system  126 , communication module (or set of instructions)  128 , contact/motion module (or set of instructions)  130 , graphics module (or set of instructions)  132 , text input module (or set of instructions)  134 , Global Positioning System (GPS) module (or set of instructions)  135 , and applications (or sets of instructions)  136 . Furthermore, in some embodiments, memory  102  ( FIG. 1A ) or  370  ( FIG. 3 ) stores device/global internal state  157 , as shown in  FIGS. 1A and 3 . Device/global internal state  157  includes one or more of: active application state, indicating which applications, if any, are currently active; display state, indicating what applications, views or other information occupy various regions of touch screen display  112 ; sensor state, including information obtained from the device&#39;s various sensors and input control devices  116 ; and location information concerning the device&#39;s location and/or attitude. 
     Operating system  126  (e.g., Darwin, RTXC, LINUX, UNIX, OS X, iOS, WINDOWS, or an embedded operating system such as VxWorks) includes various software components and/or drivers for controlling and managing general system tasks (e.g., memory management, storage device control, power management, etc.) and facilitates communication between various hardware and software components. 
     Communication module  128  facilitates communication with other devices over one or more external ports  124  and also includes various software components for handling data received by RF circuitry  108  and/or external port  124 . External port  124  (e.g., Universal Serial Bus (USB), FIREWIRE, etc.) is adapted for coupling directly to other devices or indirectly over a network (e.g., the Internet, wireless LAN, etc.). In some embodiments, the external port is a multi-pin (e.g., 30-pin) connector that is the same as, or similar to and/or compatible with, the 30-pin connector used on iPod® (trademark of Apple Inc.) devices. 
     Contact/motion module  130  optionally detects contact with touch screen  112  (in conjunction with display controller  156 ) and other touch-sensitive devices (e.g., a touchpad or physical click wheel). Contact/motion module  130  includes various software components for performing various operations related to detection of contact, such as determining if contact has occurred (e.g., detecting a finger-down event), determining an intensity of the contact (e.g., the force or pressure of the contact or a substitute for the force or pressure of the contact), determining if there is movement of the contact and tracking the movement across the touch-sensitive surface (e.g., detecting one or more finger-dragging events), and determining if the contact has ceased (e.g., detecting a finger-up event or a break in contact). Contact/motion module  130  receives contact data from the touch-sensitive surface. Determining movement of the point of contact, which is represented by a series of contact data, optionally includes determining speed (magnitude), velocity (magnitude and direction), and/or an acceleration (a change in magnitude and/or direction) of the point of contact. These operations are, optionally, applied to single contacts (e.g., one finger contacts) or to multiple simultaneous contacts (e.g., “multitouch”/multiple finger contacts). In some embodiments, contact/motion module  130  and display controller  156  detect contact on a touchpad. 
     In some embodiments, contact/motion module  130  uses a set of one or more intensity thresholds to determine whether an operation has been performed by a user (e.g., to determine whether a user has “clicked” on an icon). In some embodiments, at least a subset of the intensity thresholds are determined in accordance with software parameters (e.g., the intensity thresholds are not determined by the activation thresholds of particular physical actuators and can be adjusted without changing the physical hardware of device  100 ). For example, a mouse “click” threshold of a trackpad or touch screen display can be set to any of a large range of predefined threshold values without changing the trackpad or touch screen display hardware. Additionally, in some implementations, a user of the device is provided with software settings for adjusting one or more of the set of intensity thresholds (e.g., by adjusting individual intensity thresholds and/or by adjusting a plurality of intensity thresholds at once with a system-level click “intensity” parameter). 
     Contact/motion module  130  optionally detects a gesture input by a user. Different gestures on the touch-sensitive surface have different contact patterns (e.g., different motions, timings, and/or intensities of detected contacts). Thus, a gesture is, optionally, detected by detecting a particular contact pattern. For example, detecting a finger tap gesture includes detecting a finger-down event followed by detecting a finger-up (liftoff) event at the same position (or substantially the same position) as the finger-down event (e.g., at the position of an icon). As another example, detecting a finger swipe gesture on the touch-sensitive surface includes detecting a finger-down event followed by detecting one or more finger-dragging events, and subsequently followed by detecting a finger-up (liftoff) event. 
     Graphics module  132  includes various known software components for rendering and displaying graphics on touch screen  112  or other display, including components for changing the visual impact (e.g., brightness, transparency, saturation, contrast, or other visual property) of graphics that are displayed. As used herein, the term “graphics” includes any object that can be displayed to a user, including, without limitation, text, web pages, icons (such as user-interface objects including soft keys), digital images, videos, animations, and the like. 
     In some embodiments, graphics module  132  stores data representing graphics to be used. Each graphic is, optionally, assigned a corresponding code. Graphics module  132  receives, from applications etc., one or more codes specifying graphics to be displayed along with, if necessary, coordinate data and other graphic property data, and then generates screen image data to output to display controller  156 . 
     Haptic feedback module  133  includes various software components for generating instructions used by tactile output generator(s)  167  to produce tactile outputs at one or more locations on device  100  in response to user interactions with device  100 . 
     Text input module  134 , which is, optionally, a component of graphics module  132 , provides soft keyboards for entering text in various applications (e.g., contacts  137 , e-mail  140 , IM  141 , browser  147 , and any other application that needs text input). 
     GPS module  135  determines the location of the device and provides this information for use in various applications (e.g., to telephone  138  for use in location-based dialing; to camera  143  as picture/video metadata; and to applications that provide location-based services such as weather widgets, local yellow page widgets, and map/navigation widgets). 
     Applications  136  optionally include the following modules (or sets of instructions), or a subset or superset thereof:
         Contacts module  137  (sometimes called an address book or contact list);   Telephone module  138 ;   Video conference module  139 ;   E-mail client module  140 ;   Instant messaging (IM) module  141 ;   Workout support module  142 ;   Camera module  143  for still and/or video images;   Image management module  144 ;   Video player module;   Music player module;   Browser module  147 ;   Calendar module  148 ;   Widget modules  149 , which optionally include one or more of: weather widget  149 - 1 , stocks widget  149 - 2 , calculator widget  149 - 3 , alarm clock widget  149 - 4 , dictionary widget  149 - 5 , and other widgets obtained by the user, as well as user-created widgets  149 - 6 ;   Widget creator module  150  for making user-created widgets  149 - 6 ;   Search module  151 ;   Video and music player module  152 , which merges video player module and music player module;   Notes module  153 ;   Map module  154 ; and/or   Online video module  155 .       

     Examples of other applications  136  that are, optionally, stored in memory  102  include other word processing applications, other image editing applications, drawing applications, presentation applications, JAVA-enabled applications, encryption, digital rights management, voice recognition, and voice replication. 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , contacts module  137  are, optionally, used to manage an address book or contact list (e.g., stored in application internal state  192  of contacts module  137  in memory  102  or memory  370 ), including: adding name(s) to the address book; deleting name(s) from the address book; associating telephone number(s), e-mail address(es), physical address(es) or other information with a name; associating an image with a name; categorizing and sorting names; providing telephone numbers or e-mail addresses to initiate and/or facilitate communications by telephone  138 , video conference module  139 , e-mail  140 , or IM  141 ; and so forth. 
     In conjunction with RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , telephone module  138  are optionally, used to enter a sequence of characters corresponding to a telephone number, access one or more telephone numbers in contacts module  137 , modify a telephone number that has been entered, dial a respective telephone number, conduct a conversation, and disconnect or hang up when the conversation is completed. As noted above, the wireless communication optionally uses any of a plurality of communications standards, protocols, and technologies. 
     In conjunction with RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , touch screen  112 , display controller  156 , optical sensor  164 , optical sensor controller  158 , contact/motion module  130 , graphics module  132 , text input module  134 , contacts module  137 , and telephone module  138 , video conference module  139  includes executable instructions to initiate, conduct, and terminate a video conference between a user and one or more other participants in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , e-mail client module  140  includes executable instructions to create, send, receive, and manage e-mail in response to user instructions. In conjunction with image management module  144 , e-mail client module  140  makes it very easy to create and send e-mails with still or video images taken with camera module  143 . 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , the instant messaging module  141  includes executable instructions to enter a sequence of characters corresponding to an instant message, to modify previously entered characters, to transmit a respective instant message (for example, using a Short Message Service (SMS) or Multimedia Message Service (MMS) protocol for telephony-based instant messages or using XMPP, SIMPLE, or IMPS for Internet-based instant messages), to receive instant messages, and to view received instant messages. In some embodiments, transmitted and/or received instant messages optionally include graphics, photos, audio files, video files and/or other attachments as are supported in an MMS and/or an Enhanced Messaging Service (EMS). As used herein, “instant messaging” refers to both telephony-based messages (e.g., messages sent using SMS or MMS) and Internet-based messages (e.g., messages sent using XMPP, SIMPLE, or IMPS). 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , GPS module  135 , map module  154 , and music player module, workout support module  142  includes executable instructions to create workouts (e.g., with time, distance, and/or calorie burning goals); communicate with workout sensors (sports devices); receive workout sensor data; calibrate sensors used to monitor a workout; select and play music for a workout; and display, store, and transmit workout data. 
     In conjunction with touch screen  112 , display controller  156 , optical sensor(s)  164 , optical sensor controller  158 , contact/motion module  130 , graphics module  132 , and image management module  144 , camera module  143  includes executable instructions to capture still images or video (including a video stream) and store them into memory  102 , modify characteristics of a still image or video, or delete a still image or video from memory  102 . 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , and camera module  143 , image management module  144  includes executable instructions to arrange, modify (e.g., edit), or otherwise manipulate, label, delete, present (e.g., in a digital slide show or album), and store still and/or video images. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , browser module  147  includes executable instructions to browse the Internet in accordance with user instructions, including searching, linking to, receiving, and displaying web pages or portions thereof, as well as attachments and other files linked to web pages. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , e-mail client module  140 , and browser module  147 , calendar module  148  includes executable instructions to create, display, modify, and store calendars and data associated with calendars (e.g., calendar entries, to-do lists, etc.) in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , and browser module  147 , widget modules  149  are mini-applications that are, optionally, downloaded and used by a user (e.g., weather widget  149 - 1 , stocks widget  149 - 2 , calculator widget  149 - 3 , alarm clock widget  149 - 4 , and dictionary widget  149 - 5 ) or created by the user (e.g., user-created widget  149 - 6 ). In some embodiments, a widget includes an HTML (Hypertext Markup Language) file, a CSS (Cascading Style Sheets) file, and a JavaScript file. In some embodiments, a widget includes an XML (Extensible Markup Language) file and a JavaScript file (e.g., Yahoo! Widgets). 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , and browser module  147 , the widget creator module  150  are, optionally, used by a user to create widgets (e.g., turning a user-specified portion of a web page into a widget). 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , search module  151  includes executable instructions to search for text, music, sound, image, video, and/or other files in memory  102  that match one or more search criteria (e.g., one or more user-specified search terms) in accordance with user instructions. 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , audio circuitry  110 , speaker  111 , RF circuitry  108 , and browser module  147 , video and music player module  152  includes executable instructions that allow the user to download and play back recorded music and other sound files stored in one or more file formats, such as MP3 or AAC files, and executable instructions to display, present, or otherwise play back videos (e.g., on touch screen  112  or on an external, connected display via external port  124 ). In some embodiments, device  100  optionally includes the functionality of an MP3 player, such as an iPod (trademark of Apple Inc.). 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , and text input module  134 , notes module  153  includes executable instructions to create and manage notes, to-do lists, and the like in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , text input module  134 , GPS module  135 , and browser module  147 , map module  154  are, optionally, used to receive, display, modify, and store maps and data associated with maps (e.g., driving directions, data on stores and other points of interest at or near a particular location, and other location-based data) in accordance with user instructions. 
     In conjunction with touch screen  112 , display controller  156 , contact/motion module  130 , graphics module  132 , audio circuitry  110 , speaker  111 , RF circuitry  108 , text input module  134 , e-mail client module  140 , and browser module  147 , online video module  155  includes instructions that allow the user to access, browse, receive (e.g., by streaming and/or download), play back (e.g., on the touch screen or on an external, connected display via external port  124 ), send an e-mail with a link to a particular online video, and otherwise manage online videos in one or more file formats, such as H.264. In some embodiments, instant messaging module  141 , rather than e-mail client module  140 , is used to send a link to a particular online video. Additional description of the online video application can be found in U.S. Provisional Patent Application No. 60/936,562, “Portable Multifunction Device, Method, and Graphical User Interface for Playing Online Videos,” filed Jun. 20, 2007, and U.S. patent application Ser. No. 11/968,067, “Portable Multifunction Device, Method, and Graphical User Interface for Playing Online Videos,” filed Dec. 31, 2007, the contents of which are hereby incorporated by reference in their entirety. 
     Each of the above-identified modules and applications corresponds to a set of executable instructions for performing one or more functions described above and the methods described in this application (e.g., the computer-implemented methods and other information processing methods described herein). These modules (e.g., sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules are, optionally, combined or otherwise rearranged in various embodiments. For example, video player module is, optionally, combined with music player module into a single module (e.g., video and music player module  152 ,  FIG. 1A ). In some embodiments, memory  102  optionally stores a subset of the modules and data structures identified above. Furthermore, memory  102  optionally stores additional modules and data structures not described above. 
     In some embodiments, device  100  is a device where operation of a predefined set of functions on the device is performed exclusively through a touch screen and/or a touchpad. By using a touch screen and/or a touchpad as the primary input control device for operation of device  100 , the number of physical input control devices (such as push buttons, dials, and the like) on device  100  is, optionally, reduced. 
     The predefined set of functions that are performed exclusively through a touch screen and/or a touchpad optionally include navigation between user interfaces. In some embodiments, the touchpad, when touched by the user, navigates device  100  to a main, home, or root menu from any user interface that is displayed on device  100 . In such embodiments, a “menu button” is implemented using a touchpad. In some other embodiments, the menu button is a physical push button or other physical input control device instead of a touchpad. 
       FIG. 1B  is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. In some embodiments, memory  102  ( FIG. 1A ) or  370  ( FIG. 3 ) includes event sorter  170  (e.g., in operating system  126 ) and a respective application  136 - 1  (e.g., any of the aforementioned applications  137 - 151 ,  155 ,  380 - 390 ). 
     Event sorter  170  receives event information and determines the application  136 - 1  and application view  191  of application  136 - 1  to which to deliver the event information. Event sorter  170  includes event monitor  171  and event dispatcher module  174 . In some embodiments, application  136 - 1  includes application internal state  192 , which indicates the current application view(s) displayed on touch-sensitive display  112  when the application is active or executing. In some embodiments, device/global internal state  157  is used by event sorter  170  to determine which application(s) is (are) currently active, and application internal state  192  is used by event sorter  170  to determine application views  191  to which to deliver event information. 
     In some embodiments, application internal state  192  includes additional information, such as one or more of: resume information to be used when application  136 - 1  resumes execution, user interface state information that indicates information being displayed or that is ready for display by application  136 - 1 , a state queue for enabling the user to go back to a prior state or view of application  136 - 1 , and a redo/undo queue of previous actions taken by the user. 
     Event monitor  171  receives event information from peripherals interface  118 . Event information includes information about a sub-event (e.g., a user touch on touch-sensitive display  112 , as part of a multi-touch gesture). Peripherals interface  118  transmits information it receives from I/O subsystem  106  or a sensor, such as proximity sensor  166 , accelerometer(s)  168 , and/or microphone  113  (through audio circuitry  110 ). Information that peripherals interface  118  receives from I/O subsystem  106  includes information from touch-sensitive display  112  or a touch-sensitive surface. 
     In some embodiments, event monitor  171  sends requests to the peripherals interface  118  at predetermined intervals. In response, peripherals interface  118  transmits event information. In other embodiments, peripherals interface  118  transmits event information only when there is a significant event (e.g., receiving an input above a predetermined noise threshold and/or for more than a predetermined duration). 
     In some embodiments, event sorter  170  also includes a hit view determination module  172  and/or an active event recognizer determination module  173 . 
     Hit view determination module  172  provides software procedures for determining where a sub-event has taken place within one or more views when touch-sensitive display  112  displays more than one view. Views are made up of controls and other elements that a user can see on the display. 
     Another aspect of the user interface associated with an application is a set of views, sometimes herein called application views or user interface windows, in which information is displayed and touch-based gestures occur. The application views (of a respective application) in which a touch is detected optionally correspond to programmatic levels within a programmatic or view hierarchy of the application. For example, the lowest level view in which a touch is detected is, optionally, called the hit view, and the set of events that are recognized as proper inputs are, optionally, determined based, at least in part, on the hit view of the initial touch that begins a touch-based gesture. 
     Hit view determination module  172  receives information related to sub-events of a touch-based gesture. When an application has multiple views organized in a hierarchy, hit view determination module  172  identifies a hit view as the lowest view in the hierarchy which should handle the sub-event. In most circumstances, the hit view is the lowest level view in which an initiating sub-event occurs (e.g., the first sub-event in the sequence of sub-events that form an event or potential event). Once the hit view is identified by the hit view determination module  172 , the hit view typically receives all sub-events related to the same touch or input source for which it was identified as the hit view. 
     Active event recognizer determination module  173  determines which view or views within a view hierarchy should receive a particular sequence of sub-events. In some embodiments, active event recognizer determination module  173  determines that only the hit view should receive a particular sequence of sub-events. In other embodiments, active event recognizer determination module  173  determines that all views that include the physical location of a sub-event are actively involved views, and therefore determines that all actively involved views should receive a particular sequence of sub-events. In other embodiments, even if touch sub-events were entirely confined to the area associated with one particular view, views higher in the hierarchy would still remain as actively involved views. 
     Event dispatcher module  174  dispatches the event information to an event recognizer (e.g., event recognizer  180 ). In embodiments including active event recognizer determination module  173 , event dispatcher module  174  delivers the event information to an event recognizer determined by active event recognizer determination module  173 . In some embodiments, event dispatcher module  174  stores in an event queue the event information, which is retrieved by a respective event receiver  182 . 
     In some embodiments, operating system  126  includes event sorter  170 . Alternatively, application  136 - 1  includes event sorter  170 . In yet other embodiments, event sorter  170  is a stand-alone module, or a part of another module stored in memory  102 , such as contact/motion module  130 . 
     In some embodiments, application  136 - 1  includes a plurality of event handlers  190  and one or more application views  191 , each of which includes instructions for handling touch events that occur within a respective view of the application&#39;s user interface. Each application view  191  of the application  136 - 1  includes one or more event recognizers  180 . Typically, a respective application view  191  includes a plurality of event recognizers  180 . In other embodiments, one or more of event recognizers  180  are part of a separate module, such as a user interface kit (not shown) or a higher level object from which application  136 - 1  inherits methods and other properties. In some embodiments, a respective event handler  190  includes one or more of: data updater  176 , object updater  177 , GUI updater  178 , and/or event data  179  received from event sorter  170 . Event handler  190  optionally utilizes or calls data updater  176 , object updater  177 , or GUI updater  178  to update the application internal state  192 . Alternatively, one or more of the application views  191  include one or more respective event handlers  190 . Also, in some embodiments, one or more of data updater  176 , object updater  177 , and GUI updater  178  are included in a respective application view  191 . 
     A respective event recognizer  180  receives event information (e.g., event data  179 ) from event sorter  170  and identifies an event from the event information. Event recognizer  180  includes event receiver  182  and event comparator  184 . In some embodiments, event recognizer  180  also includes at least a subset of: metadata  183 , and event delivery instructions  188  (which optionally include sub-event delivery instructions). 
     Event receiver  182  receives event information from event sorter  170 . The event information includes information about a sub-event, for example, a touch or a touch movement. Depending on the sub-event, the event information also includes additional information, such as location of the sub-event. When the sub-event concerns motion of a touch, the event information optionally also includes speed and direction of the sub-event. In some embodiments, events include rotation of the device from one orientation to another (e.g., from a portrait orientation to a landscape orientation, or vice versa), and the event information includes corresponding information about the current orientation (also called device attitude) of the device. 
     Event comparator  184  compares the event information to predefined event or sub-event definitions and, based on the comparison, determines an event or sub-event, or determines or updates the state of an event or sub-event. In some embodiments, event comparator  184  includes event definitions  186 . Event definitions  186  contain definitions of events (e.g., predefined sequences of sub-events), for example, event  1  ( 187 - 1 ), event  2  ( 187 - 2 ), and others. In some embodiments, sub-events in an event ( 187 ) include, for example, touch begin, touch end, touch movement, touch cancellation, and multiple touching. In one example, the definition for event  1  ( 187 - 1 ) is a double tap on a displayed object. The double tap, for example, comprises a first touch (touch begin) on the displayed object for a predetermined phase, a first liftoff (touch end) for a predetermined phase, a second touch (touch begin) on the displayed object for a predetermined phase, and a second liftoff (touch end) for a predetermined phase. In another example, the definition for event  2  ( 187 - 2 ) is a dragging on a displayed object. The dragging, for example, comprises a touch (or contact) on the displayed object for a predetermined phase, a movement of the touch across touch-sensitive display  112 , and liftoff of the touch (touch end). In some embodiments, the event also includes information for one or more associated event handlers  190 . 
     In some embodiments, event definition  187  includes a definition of an event for a respective user-interface object. In some embodiments, event comparator  184  performs a hit test to determine which user-interface object is associated with a sub-event. For example, in an application view in which three user-interface objects are displayed on touch-sensitive display  112 , when a touch is detected on touch-sensitive display  112 , event comparator  184  performs a hit test to determine which of the three user-interface objects is associated with the touch (sub-event). If each displayed object is associated with a respective event handler  190 , the event comparator uses the result of the hit test to determine which event handler  190  should be activated. For example, event comparator  184  selects an event handler associated with the sub-event and the object triggering the hit test. 
     In some embodiments, the definition for a respective event ( 187 ) also includes delayed actions that delay delivery of the event information until after it has been determined whether the sequence of sub-events does or does not correspond to the event recognizer&#39;s event type. 
     When a respective event recognizer  180  determines that the series of sub-events do not match any of the events in event definitions  186 , the respective event recognizer  180  enters an event impossible, event failed, or event ended state, after which it disregards subsequent sub-events of the touch-based gesture. In this situation, other event recognizers, if any, that remain active for the hit view continue to track and process sub-events of an ongoing touch-based gesture. 
     In some embodiments, a respective event recognizer  180  includes metadata  183  with configurable properties, flags, and/or lists that indicate how the event delivery system should perform sub-event delivery to actively involved event recognizers. In some embodiments, metadata  183  includes configurable properties, flags, and/or lists that indicate how event recognizers interact, or are enabled to interact, with one another. In some embodiments, metadata  183  includes configurable properties, flags, and/or lists that indicate whether sub-events are delivered to varying levels in the view or programmatic hierarchy. 
     In some embodiments, a respective event recognizer  180  activates event handler  190  associated with an event when one or more particular sub-events of an event are recognized. In some embodiments, a respective event recognizer  180  delivers event information associated with the event to event handler  190 . Activating an event handler  190  is distinct from sending (and deferred sending) sub-events to a respective hit view. In some embodiments, event recognizer  180  throws a flag associated with the recognized event, and event handler  190  associated with the flag catches the flag and performs a predefined process. 
     In some embodiments, event delivery instructions  188  include sub-event delivery instructions that deliver event information about a sub-event without activating an event handler. Instead, the sub-event delivery instructions deliver event information to event handlers associated with the series of sub-events or to actively involved views. Event handlers associated with the series of sub-events or with actively involved views receive the event information and perform a predetermined process. 
     In some embodiments, data updater  176  creates and updates data used in application  136 - 1 . For example, data updater  176  updates the telephone number used in contacts module  137 , or stores a video file used in video player module. In some embodiments, object updater  177  creates and updates objects used in application  136 - 1 . For example, object updater  177  creates a new user-interface object or updates the position of a user-interface object. GUI updater  178  updates the GUI. For example, GUI updater  178  prepares display information and sends it to graphics module  132  for display on a touch-sensitive display. 
     In some embodiments, event handler(s)  190  includes or has access to data updater  176 , object updater  177 , and GUI updater  178 . In some embodiments, data updater  176 , object updater  177 , and GUI updater  178  are included in a single module of a respective application  136 - 1  or application view  191 . In other embodiments, they are included in two or more software modules. 
     It shall be understood that the foregoing discussion regarding event handling of user touches on touch-sensitive displays also applies to other forms of user inputs to operate multifunction devices  100  with input devices, not all of which are initiated on touch screens. For example, mouse movement and mouse button presses, optionally coordinated with single or multiple keyboard presses or holds; contact movements such as taps, drags, scrolls, etc. on touchpads; pen stylus inputs; movement of the device; oral instructions; detected eye movements; biometric inputs; and/or any combination thereof are optionally utilized as inputs corresponding to sub-events which define an event to be recognized. 
       FIG. 2  illustrates a portable multifunction device  100  having a touch screen  112  in accordance with some embodiments. The touch screen optionally displays one or more graphics within user interface (UI)  200 . In this embodiment, as well as others described below, a user is enabled to select one or more of the graphics by making a gesture on the graphics, for example, with one or more fingers  202  (not drawn to scale in the figure) or one or more styluses  203  (not drawn to scale in the figure). In some embodiments, selection of one or more graphics occurs when the user breaks contact with the one or more graphics. In some embodiments, the gesture optionally includes one or more taps, one or more swipes (from left to right, right to left, upward and/or downward), and/or a rolling of a finger (from right to left, left to right, upward and/or downward) that has made contact with device  100 . In some implementations or circumstances, inadvertent contact with a graphic does not select the graphic. For example, a swipe gesture that sweeps over an application icon optionally does not select the corresponding application when the gesture corresponding to selection is a tap. 
     Device  100  optionally also include one or more physical buttons, such as “home” or menu button  204 . As described previously, menu button  204  is, optionally, used to navigate to any application  136  in a set of applications that are, optionally, executed on device  100 . Alternatively, in some embodiments, the menu button is implemented as a soft key in a GUI displayed on touch screen  112 . 
     In some embodiments, device  100  includes touch screen  112 , menu button  204 , push button  206  for powering the device on/off and locking the device, volume adjustment button(s)  208 , subscriber identity module (SIM) card slot  210 , headset jack  212 , and docking/charging external port  124 . Push button  206  is, optionally, used to turn the power on/off on the device by depressing the button and holding the button in the depressed state for a predefined time interval; to lock the device by depressing the button and releasing the button before the predefined time interval has elapsed; and/or to unlock the device or initiate an unlock process. In an alternative embodiment, device  100  also accepts verbal input for activation or deactivation of some functions through microphone  113 . Device  100  also, optionally, includes one or more contact intensity sensors  165  for detecting intensity of contacts on touch screen  112  and/or one or more tactile output generators  167  for generating tactile outputs for a user of device  100 . 
       FIG. 3  is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface in accordance with some embodiments. Device  300  need not be portable. In some embodiments, device  300  is a laptop computer, a desktop computer, a tablet computer, a multimedia player device, a navigation device, an educational device (such as a child&#39;s learning toy), a gaming system, or a control device (e.g., a home or industrial controller). Device  300  typically includes one or more processing units (CPUs)  310 , one or more network or other communications interfaces  360 , memory  370 , and one or more communication buses  320  for interconnecting these components. Communication buses  320  optionally include circuitry (sometimes called a chipset) that interconnects and controls communications between system components. Device  300  includes input/output (I/O) interface  330  comprising display  340 , which is typically a touch screen display. I/O interface  330  also optionally includes a keyboard and/or mouse (or other pointing device)  350  and touchpad  355 , tactile output generator  357  for generating tactile outputs on device  300  (e.g., similar to tactile output generator(s)  167  described above with reference to  FIG. 1A ), sensors  359  (e.g., optical, acceleration, proximity, touch-sensitive, and/or contact intensity sensors similar to contact intensity sensor(s)  165  described above with reference to  FIG. 1A ). Memory  370  includes high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices; and optionally includes non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory  370  optionally includes one or more storage devices remotely located from CPU(s)  310 . In some embodiments, memory  370  stores programs, modules, and data structures analogous to the programs, modules, and data structures stored in memory  102  of portable multifunction device  100  ( FIG. 1A ), or a subset thereof. Furthermore, memory  370  optionally stores additional programs, modules, and data structures not present in memory  102  of portable multifunction device  100 . For example, memory  370  of device  300  optionally stores drawing module  380 , presentation module  382 , word processing module  384 , website creation module  386 , disk authoring module  388 , and/or spreadsheet module  390 , while memory  102  of portable multifunction device  100  ( FIG. 1A ) optionally does not store these modules. 
     Each of the above-identified elements in  FIG. 3  is, optionally, stored in one or more of the previously mentioned memory devices. Each of the above-identified modules corresponds to a set of instructions for performing a function described above. The above-identified modules or programs (e.g., sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules are, optionally, combined or otherwise rearranged in various embodiments. In some embodiments, memory  370  optionally stores a subset of the modules and data structures identified above. Furthermore, memory  370  optionally stores additional modules and data structures not described above. 
     Attention is now directed towards embodiments of user interfaces that are, optionally, implemented on, for example, portable multifunction device  100 . 
       FIG. 4A  illustrates an exemplary user interface for a menu of applications on portable multifunction device  100  in accordance with some embodiments. Similar user interfaces are, optionally, implemented on device  300 . In some embodiments, user interface  400  includes the following elements, or a subset or superset thereof:
         Signal strength indicator(s)  402  for wireless communication(s), such as cellular and Wi-Fi signals;   Time  404 ;   Bluetooth indicator  405 ;   Battery status indicator  406 ;   Tray  408  with icons for frequently used applications, such as:
           Icon  416  for telephone module  138 , labeled “Phone,” which optionally includes an indicator  414  of the number of missed calls or voicemail messages;   Icon  418  for e-mail client module  140 , labeled “Mail,” which optionally includes an indicator  410  of the number of unread e-mails;   Icon  420  for browser module  147 , labeled “Browser;” and   Icon  422  for video and music player module  152 , also referred to as iPod (trademark of Apple Inc.) module  152 , labeled “iPod;” and   
           Icons for other applications, such as:
           Icon  424  for IM module  141 , labeled “Messages;”   Icon  426  for calendar module  148 , labeled “Calendar;”   Icon  428  for image management module  144 , labeled “Photos;”   Icon  430  for camera module  143 , labeled “Camera;”   Icon  432  for online video module  155 , labeled “Online Video;”   Icon  434  for stocks widget  149 - 2 , labeled “Stocks;”   Icon  436  for map module  154 , labeled “Maps;”   Icon  438  for weather widget  149 - 1 , labeled “Weather;”   Icon  440  for alarm clock widget  149 - 4 , labeled “Clock;”   Icon  442  for workout support module  142 , labeled “Workout Support;”   Icon  444  for notes module  153 , labeled “Notes;” and   Icon  446  for a settings application or module, labeled “Settings,” which provides access to settings for device  100  and its various applications  136 .   
               

     It should be noted that the icon labels illustrated in  FIG. 4A  are merely exemplary. For example, icon  422  for video and music player module  152  is labeled “Music” or “Music Player.” Other labels are, optionally, used for various application icons. In some embodiments, a label for a respective application icon includes a name of an application corresponding to the respective application icon. In some embodiments, a label for a particular application icon is distinct from a name of an application corresponding to the particular application icon. 
       FIG. 4B  illustrates an exemplary user interface on a device (e.g., device  300 ,  FIG. 3 ) with a touch-sensitive surface  451  (e.g., a tablet or touchpad  355 ,  FIG. 3 ) that is separate from the display  450  (e.g., touch screen display  112 ). Device  300  also, optionally, includes one or more contact intensity sensors (e.g., one or more of sensors  359 ) for detecting intensity of contacts on touch-sensitive surface  451  and/or one or more tactile output generators  357  for generating tactile outputs for a user of device  300 . 
     Although some of the examples that follow will be given with reference to inputs on touch screen display  112  (where the touch-sensitive surface and the display are combined), in some embodiments, the device detects inputs on a touch-sensitive surface that is separate from the display, as shown in  FIG. 4B . In some embodiments, the touch-sensitive surface (e.g.,  451  in  FIG. 4B ) has a primary axis (e.g.,  452  in  FIG. 4B ) that corresponds to a primary axis (e.g.,  453  in  FIG. 4B ) on the display (e.g.,  450 ). In accordance with these embodiments, the device detects contacts (e.g.,  460  and  462  in  FIG. 4B ) with the touch-sensitive surface  451  at locations that correspond to respective locations on the display (e.g., in  FIG. 4B, 460  corresponds to  468  and  462  corresponds to  470 ). In this way, user inputs (e.g., contacts  460  and  462 , and movements thereof) detected by the device on the touch-sensitive surface (e.g.,  451  in  FIG. 4B ) are used by the device to manipulate the user interface on the display (e.g.,  450  in  FIG. 4B ) of the multifunction device when the touch-sensitive surface is separate from the display. It should be understood that similar methods are, optionally, used for other user interfaces described herein. 
     Additionally, while the following examples are given primarily with reference to finger inputs (e.g., finger contacts, finger tap gestures, finger swipe gestures), it should be understood that, in some embodiments, one or more of the finger inputs are replaced with input from another input device (e.g., a mouse-based input or stylus input). For example, a swipe gesture is, optionally, replaced with a mouse click (e.g., instead of a contact) followed by movement of the cursor along the path of the swipe (e.g., instead of movement of the contact). As another example, a tap gesture is, optionally, replaced with a mouse click while the cursor is located over the location of the tap gesture (e.g., instead of detection of the contact followed by ceasing to detect the contact). Similarly, when multiple user inputs are simultaneously detected, it should be understood that multiple computer mice are, optionally, used simultaneously, or a mouse and finger contacts are, optionally, used simultaneously. 
       FIG. 5A  illustrates exemplary personal electronic device  500 . Device  500  includes body  502 . In some embodiments, device  500  can include some or all of the features described with respect to devices  100  and  300  (e.g.,  FIGS. 1A-4B ). In some embodiments, device  500  has touch-sensitive display screen  504 , hereafter touch screen  504 . Alternatively, or in addition to touch screen  504 , device  500  has a display and a touch-sensitive surface. As with devices  100  and  300 , in some embodiments, touch screen  504  (or the touch-sensitive surface) optionally includes one or more intensity sensors for detecting intensity of contacts (e.g., touches) being applied. The one or more intensity sensors of touch screen  504  (or the touch-sensitive surface) can provide output data that represents the intensity of touches. The user interface of device  500  can respond to touches based on their intensity, meaning that touches of different intensities can invoke different user interface operations on device  500 . 
     Exemplary techniques for detecting and processing touch intensity are found, for example, in related applications: International Patent Application Serial No. PCT/US2013/040061, titled “Device, Method, and Graphical User Interface for Displaying User Interface Objects Corresponding to an Application,” filed May 8, 2013, published as WIPO Publication No. WO/2013/169849, and International Patent Application Serial No. PCT/US2013/069483, titled “Device, Method, and Graphical User Interface for Transitioning Between Touch Input to Display Output Relationships,” filed Nov. 11, 2013, published as WIPO Publication No. WO/2014/105276, each of which is hereby incorporated by reference in their entirety. 
     In some embodiments, device  500  has one or more input mechanisms  506  and  508 . Input mechanisms  506  and  508 , if included, can be physical. Examples of physical input mechanisms include push buttons and rotatable mechanisms. In some embodiments, device  500  has one or more attachment mechanisms. Such attachment mechanisms, if included, can permit attachment of device  500  with, for example, hats, eyewear, earrings, necklaces, shirts, jackets, bracelets, watch straps, chains, trousers, belts, shoes, purses, backpacks, and so forth. These attachment mechanisms permit device  500  to be worn by a user. 
       FIG. 5B  depicts exemplary personal electronic device  500 . In some embodiments, device  500  can include some or all of the components described with respect to  FIGS. 1A, 1B , and  3 . Device  500  has bus  512  that operatively couples I/O section  514  with one or more computer processors  516  and memory  518 . I/O section  514  can be connected to display  504 , which can have touch-sensitive component  522  and, optionally, intensity sensor  524  (e.g., contact intensity sensor). In addition, I/O section  514  can be connected with communication unit  530  for receiving application and operating system data, using Wi-Fi, Bluetooth, near field communication (NFC), cellular, and/or other wireless communication techniques. Device  500  can include input mechanisms  506  and/or  508 . Input mechanism  506  is, optionally, a rotatable input device or a depressible and rotatable input device, for example. Input mechanism  508  is, optionally, a button, in some examples. 
     Input mechanism  508  is, optionally, a microphone, in some examples. Personal electronic device  500  optionally includes various sensors, such as GPS sensor  532 , accelerometer  534 , directional sensor  540  (e.g., compass), gyroscope  536 , motion sensor  538 , and/or a combination thereof, all of which can be operatively connected to I/O section  514 . 
     Memory  518  of personal electronic device  500  can include one or more non-transitory computer-readable storage mediums, for storing computer-executable instructions, which, when executed by one or more computer processors  516 , for example, can cause the computer processors to perform the techniques described below, including processes  900 - 1100  ( FIGS. 9-11 ) and processes  1200  and  1300  ( FIGS. 12 and 13 ). A computer-readable storage medium can be any medium that can tangibly contain or store computer-executable instructions for use by or in connection with the instruction execution system, apparatus, or device. In some examples, the storage medium is a transitory computer-readable storage medium. In some examples, the storage medium is a non-transitory computer-readable storage medium. The non-transitory computer-readable storage medium can include, but is not limited to, magnetic, optical, and/or semiconductor storages. Examples of such storage include magnetic disks, optical discs based on CD, DVD, or Blu-ray technologies, as well as persistent solid-state memory such as flash, solid-state drives, and the like. Personal electronic device  500  is not limited to the components and configuration of  FIG. 5B , but can include other or additional components in multiple configurations. 
     As used here, the term “affordance” refers to a user-interactive graphical user interface object that is, optionally, displayed on the display screen of devices  100 ,  300 , and/or  500  ( FIGS. 1A, 3, and 5A-5B ). For example, an image (e.g., icon), a button, and text (e.g., hyperlink) each optionally constitute an affordance. 
     As used herein, the term “focus selector” refers to an input element that indicates a current part of a user interface with which a user is interacting. In some implementations that include a cursor or other location marker, the cursor acts as a “focus selector” so that when an input (e.g., a press input) is detected on a touch-sensitive surface (e.g., touchpad  355  in  FIG. 3  or touch-sensitive surface  451  in  FIG. 4B ) while the cursor is over a particular user interface element (e.g., a button, window, slider, or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations that include a touch screen display (e.g., touch-sensitive display system  112  in  FIG. 1A  or touch screen  112  in  FIG. 4A ) that enables direct interaction with user interface elements on the touch screen display, a detected contact on the touch screen acts as a “focus selector” so that when an input (e.g., a press input by the contact) is detected on the touch screen display at a location of a particular user interface element (e.g., a button, window, slider, or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations, focus is moved from one region of a user interface to another region of the user interface without corresponding movement of a cursor or movement of a contact on a touch screen display (e.g., by using a tab key or arrow keys to move focus from one button to another button); in these implementations, the focus selector moves in accordance with movement of focus between different regions of the user interface. Without regard to the specific form taken by the focus selector, the focus selector is generally the user interface element (or contact on a touch screen display) that is controlled by the user so as to communicate the user&#39;s intended interaction with the user interface (e.g., by indicating, to the device, the element of the user interface with which the user is intending to interact). For example, the location of a focus selector (e.g., a cursor, a contact, or a selection box) over a respective button while a press input is detected on the touch-sensitive surface (e.g., a touchpad or touch screen) will indicate that the user is intending to activate the respective button (as opposed to other user interface elements shown on a display of the device). 
     As used in the specification and claims, the term “characteristic intensity” of a contact refers to a characteristic of the contact based on one or more intensities of the contact. In some embodiments, the characteristic intensity is based on multiple intensity samples. The characteristic intensity is, optionally, based on a predefined number of intensity samples, or a set of intensity samples collected during a predetermined time period (e.g., 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10 seconds) relative to a predefined event (e.g., after detecting the contact, prior to detecting liftoff of the contact, before or after detecting a start of movement of the contact, prior to detecting an end of the contact, before or after detecting an increase in intensity of the contact, and/or before or after detecting a decrease in intensity of the contact). A characteristic intensity of a contact is, optionally, based on one or more of: a maximum value of the intensities of the contact, a mean value of the intensities of the contact, an average value of the intensities of the contact, a top 10 percentile value of the intensities of the contact, a value at the half maximum of the intensities of the contact, a value at the 90 percent maximum of the intensities of the contact, or the like. In some embodiments, the duration of the contact is used in determining the characteristic intensity (e.g., when the characteristic intensity is an average of the intensity of the contact over time). In some embodiments, the characteristic intensity is compared to a set of one or more intensity thresholds to determine whether an operation has been performed by a user. For example, the set of one or more intensity thresholds optionally includes a first intensity threshold and a second intensity threshold. In this example, a contact with a characteristic intensity that does not exceed the first threshold results in a first operation, a contact with a characteristic intensity that exceeds the first intensity threshold and does not exceed the second intensity threshold results in a second operation, and a contact with a characteristic intensity that exceeds the second threshold results in a third operation. In some embodiments, a comparison between the characteristic intensity and one or more thresholds is used to determine whether or not to perform one or more operations (e.g., whether to perform a respective operation or forgo performing the respective operation), rather than being used to determine whether to perform a first operation or a second operation. 
     In some embodiments, a portion of a gesture is identified for purposes of determining a characteristic intensity. For example, a touch-sensitive surface optionally receives a continuous swipe contact transitioning from a start location and reaching an end location, at which point the intensity of the contact increases. In this example, the characteristic intensity of the contact at the end location is, optionally, based on only a portion of the continuous swipe contact, and not the entire swipe contact (e.g., only the portion of the swipe contact at the end location). In some embodiments, a smoothing algorithm is, optionally, applied to the intensities of the swipe contact prior to determining the characteristic intensity of the contact. For example, the smoothing algorithm optionally includes one or more of: an unweighted sliding-average smoothing algorithm, a triangular smoothing algorithm, a median filter smoothing algorithm, and/or an exponential smoothing algorithm. In some circumstances, these smoothing algorithms eliminate narrow spikes or dips in the intensities of the swipe contact for purposes of determining a characteristic intensity. 
     The intensity of a contact on the touch-sensitive surface is, optionally, characterized relative to one or more intensity thresholds, such as a contact-detection intensity threshold, a light press intensity threshold, a deep press intensity threshold, and/or one or more other intensity thresholds. In some embodiments, the light press intensity threshold corresponds to an intensity at which the device will perform operations typically associated with clicking a button of a physical mouse or a trackpad. In some embodiments, the deep press intensity threshold corresponds to an intensity at which the device will perform operations that are different from operations typically associated with clicking a button of a physical mouse or a trackpad. In some embodiments, when a contact is detected with a characteristic intensity below the light press intensity threshold (e.g., and above a nominal contact-detection intensity threshold below which the contact is no longer detected), the device will move a focus selector in accordance with movement of the contact on the touch-sensitive surface without performing an operation associated with the light press intensity threshold or the deep press intensity threshold. Generally, unless otherwise stated, these intensity thresholds are consistent between different sets of user interface figures. 
     An increase of characteristic intensity of the contact from an intensity below the light press intensity threshold to an intensity between the light press intensity threshold and the deep press intensity threshold is sometimes referred to as a “light press” input. An increase of characteristic intensity of the contact from an intensity below the deep press intensity threshold to an intensity above the deep press intensity threshold is sometimes referred to as a “deep press” input. An increase of characteristic intensity of the contact from an intensity below the contact-detection intensity threshold to an intensity between the contact-detection intensity threshold and the light press intensity threshold is sometimes referred to as detecting the contact on the touch-surface. A decrease of characteristic intensity of the contact from an intensity above the contact-detection intensity threshold to an intensity below the contact-detection intensity threshold is sometimes referred to as detecting liftoff of the contact from the touch-surface. In some embodiments, the contact-detection intensity threshold is zero. In some embodiments, the contact-detection intensity threshold is greater than zero. 
     In some embodiments described herein, one or more operations are performed in response to detecting a gesture that includes a respective press input or in response to detecting the respective press input performed with a respective contact (or a plurality of contacts), where the respective press input is detected based at least in part on detecting an increase in intensity of the contact (or plurality of contacts) above a press-input intensity threshold. In some embodiments, the respective operation is performed in response to detecting the increase in intensity of the respective contact above the press-input intensity threshold (e.g., a “down stroke” of the respective press input). In some embodiments, the press input includes an increase in intensity of the respective contact above the press-input intensity threshold and a subsequent decrease in intensity of the contact below the press-input intensity threshold, and the respective operation is performed in response to detecting the subsequent decrease in intensity of the respective contact below the press-input threshold (e.g., an “up stroke” of the respective press input). 
     In some embodiments, the device employs intensity hysteresis to avoid accidental inputs sometimes termed “jitter,” where the device defines or selects a hysteresis intensity threshold with a predefined relationship to the press-input intensity threshold (e.g., the hysteresis intensity threshold is X intensity units lower than the press-input intensity threshold or the hysteresis intensity threshold is 75%, 90%, or some reasonable proportion of the press-input intensity threshold). Thus, in some embodiments, the press input includes an increase in intensity of the respective contact above the press-input intensity threshold and a subsequent decrease in intensity of the contact below the hysteresis intensity threshold that corresponds to the press-input intensity threshold, and the respective operation is performed in response to detecting the subsequent decrease in intensity of the respective contact below the hysteresis intensity threshold (e.g., an “up stroke” of the respective press input). Similarly, in some embodiments, the press input is detected only when the device detects an increase in intensity of the contact from an intensity at or below the hysteresis intensity threshold to an intensity at or above the press-input intensity threshold and, optionally, a subsequent decrease in intensity of the contact to an intensity at or below the hysteresis intensity, and the respective operation is performed in response to detecting the press input (e.g., the increase in intensity of the contact or the decrease in intensity of the contact, depending on the circumstances). 
     For ease of explanation, the descriptions of operations performed in response to a press input associated with a press-input intensity threshold or in response to a gesture including the press input are, optionally, triggered in response to detecting either: an increase in intensity of a contact above the press-input intensity threshold, an increase in intensity of a contact from an intensity below the hysteresis intensity threshold to an intensity above the press-input intensity threshold, a decrease in intensity of the contact below the press-input intensity threshold, and/or a decrease in intensity of the contact below the hysteresis intensity threshold corresponding to the press-input intensity threshold. Additionally, in examples where an operation is described as being performed in response to detecting a decrease in intensity of a contact below the press-input intensity threshold, the operation is, optionally, performed in response to detecting a decrease in intensity of the contact below a hysteresis intensity threshold corresponding to, and lower than, the press-input intensity threshold. 
     As used herein, an “installed application” refers to a software application that has been downloaded onto an electronic device (e.g., devices  100 ,  300 , and/or  500 ) and is ready to be launched (e.g., become opened) on the device. In some embodiments, a downloaded application becomes an installed application by way of an installation program that extracts program portions from a downloaded package and integrates the extracted portions with the operating system of the computer system. 
     As used herein, the terms “open application” or “executing application” refer to a software application with retained state information (e.g., as part of device/global internal state  157  and/or application internal state  192 ). An open or executing application is, optionally, any one of the following types of applications:
         an active application, which is currently displayed on a display screen of the device that the application is being used on;   a background application (or background processes), which is not currently displayed, but one or more processes for the application are being processed by one or more processors; and   a suspended or hibernated application, which is not running, but has state information that is stored in memory (volatile and non-volatile, respectively) and that can be used to resume execution of the application.       

     As used herein, the term “closed application” refers to software applications without retained state information (e.g., state information for closed applications is not stored in a memory of the device). Accordingly, closing an application includes stopping and/or removing application processes for the application and removing state information for the application from the memory of the device. Generally, opening a second application while in a first application does not close the first application. When the second application is displayed and the first application ceases to be displayed, the first application becomes a background application. 
     Referring now to an exemplary wireless communication network that is used by electronic devices, and to  FIG. 17 , mobile device  1700  (e.g., device  100 ,  300 , or  500 ) communicates with network  1702  over primary communication channel  1704 . Primary communication channel  1704  may allow transmission of media (e.g., voice, video, multimedia) data to and from mobile device  1700  according to various Voice over Internet Protocol (VoIP) methodologies. Generally, VoIP refers to technologies or methodologies by which multimedia and/or voice communication sessions are delivered over Internet Protocol (IP) networks (e.g., the public Internet), rather than traditional circuit switched networks such as the public switched telephone network. In particular, VoIP communications involve signaling and channel setup (sometimes referred to as session initiation) between VoIP-enabled devices and digital conversion of analog voice signals recorded on a device. Digitized media data is then transmitted in the form of IP data packets (encoded using a suitable audio or video codec) over one or more channels of a packet-switched network (e.g., communication channel  1704 ). Typically, these IP data packets are structured in standard formats according to a particular VoIP standard so that media, control, and other information is recognizable by VoIP enabled devices. 
     In the example of  FIG. 17 , primary communication channel  1704  is a WiFi network radio access technology (RAT), whereby mobile device  1700  (e.g., a device having one or more features of devices  100 ,  300 , or  500 ) communicates with a remote device  1706  (e.g., an external device having one or more features of devices  100 ,  300 , or  500 ) though network  1702  (e.g., a network including an internet server) using a WiFi access point. As discussed in more detail below, mobile device  1700  optionally also establishes a secondary communication channel  1708 . In the example of  FIG. 17 , secondary communication channel  1708  is a cellular network RAT, whereby mobile device  1700  communicates with external device  1706  through a cellular base station. It should be appreciated that this example is merely illustrative. Secondary communication channel  1708  is, optionally, also a WiFi RAT or any other suitable radio access technology. Establishing secondary communication channel  1708  optionally allows mobile device  1700  to switch to another more suitable communication channel in case of deteriorating uplink quality on primary channel  1704 . 
     Though not shown, external device  1706  optionally also has one or more communication channels to network  1702 , which may be a WiFi, cellular, or any other suitable channel. 
     Exemplary techniques for voice communications (e.g., using VoIP) are found, for example, in related patents and patent application publications: U.S. Pat. No. 9,325,941, titled “Communication Channel Management for Real-Time Applications,” filed May 30, 2014, U.S. Pat. No. 9,350,770, titled “Redundant Transmission Channels for Real-Time Applications on Mobile Devices,” filed Jul. 23, 2014, U.S. Patent Publication No. 2014/0072000, titled “Adaptive Jitter Buffer Management for Networks with Varying Conditions,” filed Sep. 6, 2013, published as WIPO Publication No. WO/2014/039843, and U.S. Pat. No. 9,628,758, titled “Communication Channel Management for Real-Time Applications,” filed Mar. 15, 2016, each of which is hereby incorporated by reference with respect to their discussions of voice communication techniques and protocols. 
     Attention is now directed towards embodiments of user interfaces (“UI”) and associated processes that are implemented on an electronic device, such as portable multifunction device  100 , device  300 , or device  500 , to provide electronic communication functionalities, such as voice communications. 
     The following figures starting with the set of  FIGS. 6AA to 6AI  through ending with the set of  FIGS. 6OA to 6OH  illustrate exemplary user interfaces for electronic communications, and transitions between the user interfaces, in accordance with some embodiments. The user interfaces in these figures are used to illustrate the processes described below, including the processes shown at  FIGS. 9 and 11 . It is noted that the flow of the user interfaces presented herein are only some examples of a variety of possible flows available in the voice communications techniques disclosed herein, and that in some cases, the flow of user interfaces can be modified and/or rearranged without departing from the spirit of the invention. 
       FIGS. 6AA to 6AI  depict exemplary user interfaces and transitions thereof for voice communications between the users of computing devices  600  and  699   a . Each of devices  600  and  699   a  is device  100 ,  300 , or  500  ( FIGS. 1A-B ,  3 , and  5 A-B) in some embodiments. For clarity, the top row of illustrations in  FIGS. 6AA to 6AI  corresponds to user interfaces displayed on device  600 , and the bottom row of illustrations corresponds to user interfaces displayed on device  699   a . For purposes of description, device  699   a  is referred to as external device  699   a . It is contemplated that each of devices  600  and  699   a  displays user interfaces described below on a display screen in conjunction with a touch-sensitive surface, otherwise referred to as a touch-sensitive display screen. It is further contemplated that each of devices  600  and  699   a  includes a microphone (e.g., input mechanism  508 , microphone  113 , described above) for detecting voice input and a speaker (e.g., speaker  111 , described above) for outputting audible data, including voice data, although such components can be provided externally in operative communication with the device (e.g., headphones). 
     As shown at  FIG. 6AA , device  600  displays a talk user interface  602  for communicating with a user at external device  699   a . For ease of description, the user at device  600  is named John Appleseed (also referred to as “John”) and the user at external device  699   a  is a contact (herein also referred to as an external contact) named Jane Appleseed (also referred to as “Jane”). At device  600 , the talk user interface  602  includes an affordance representing the external contact at the external device  699   a , such as contact affordance  604  representing an image or headshot of Jane. In examples where an image of the contact is not available, other representations are provided at the affordance, such as a monogram based on first and last initials of the contact&#39;s name and/or an unknown silhouette. In some examples as discussed below, the contact affordance  604 , and/or visual indications and animations displayed thereat, provide visual feedback indicating when voice communications are being received at device  600  from the contact&#39;s device  699   a.    
     At device  600 , the talk user interface  602  further includes a talk affordance  606  that when activated, initiates, captures, and/or sends voice communications from device  600  to the external device  699   a  in various methods described below. The talk affordance  606  can include text conveying instructions for activation, such as “press to talk.” In some examples, talk affordance  606  is activated for a duration of time while a touch input remains detected on the affordance (e.g., at a location on the touch-sensitive display screen corresponding to the affordance, also referred to herein as a tap target area of the affordance). For instance, a press-and-hold gesture (e.g., finger gesture) that remains in contact with the touch-sensitive display screen for a prolonged duration before liftoff defines the duration of time that the talk affordance  606  is activated for causing capturing voice input from a speaker at the device  600  (e.g., John&#39;s device) and sending voice data corresponding to the voice input to the external device  699   a.    
     For purposes of this disclosure, a press-and-hold gesture is utilized herein for activating the talk affordance  606 . However, gestures other than press-and-hold gestures are contemplated, such as single or multiple tap inputs. Merely by way of example, a first tap on the talk affordance  606  activates the talk affordance  606  that stays activated until detection of a subsequent second tap input on the talk affordance  606  that deactivates its functionalities, thereby toggling the talk affordance on-and-off. Still, various other gestures, such as multiple-finger (e.g., multi-touch input) gestures, an on gesture (e.g., single tap) that is distinct from an off gesture (e.g., double tap), and/or activation of the talk affordance  606  via physical buttons, can be implemented for causing the functions associated with the talk affordance  606 . In some examples as discussed below, the talk affordance  606 , and/or visual indications and animations displayed thereat, provide visual feedback indicating when voice communications are being captured at device  600  and transmitted to the contact&#39;s device  699   a.    
     At device  600 , the talk user interface  602  provides a visual indication  608  that the talk affordance  606 , or in general that voice communications occurring at the talk user interface  602  itself, is associated with the specific contact represented at the contact affordance  604 . In the present example, visual indication  608  is a single border that surrounds contact affordance  604  and talk affordance  606 , such as two merged circles surrounding the circle-shaped affordances  604 , 606 . For example, the single border is a highlighted region or background displayed at or behind the affordances  604 ,  606  that is distinct from a background in remaining portions of the talk user interface  602 . For example, the single border is a solid white background surrounding contact affordance  604  and talk affordance  606  while a remaining background of the talk user interface  602  is black. In some examples, the visual indication  608  distinguishes the contact in communication from other contacts not in communication when they are displayed in the talk user interface  602 . Additional and/or alternative visual indications include matching colors at the contact affordance  604  and talk affordance  606 , animations, visual linkages between the two separately displayed affordances  604 , 606 , and so on. In another aspect, the talk user interface  602  including the talk affordance  606  and single contact affordance  604  without displaying other contacts is, in itself, a visual indication that the talk affordance  606  is currently associated with that contact only. 
     At device  600 , the talk user interface  602  further includes a volume indicator  610  and a do-not-disturb toggle or switch  612 . The volume indicator  610  provides visual indication of a volume level for outputting audio data, such as voice data representing Jane&#39;s speech that is received from the external device  699   a . The switch  612  is displayed at an on position and can be toggled off (e.g., via tap input) to disconnect the device  600  from voice communications with the specific contact, Jane, and/or from all contacts, as described further below. 
     Further as shown in the present examples, while displaying the talk user interface  602 , the device  600  further displays a current time  614  as an integrated element in the talk user interface  602  and/or displayed concurrently with the talk user interface  602 . In some examples, the device  600  is a wearable electronic device, such as a smart watch having one or more input mechanisms  506  and  508  described above, such as a physically rotatable input mechanism  616  (e.g., a rotatable crown) and/or physical push-button mechanism  618 . It is further noted that in the present example, the talk affordance  606  has a greater tap target area (e.g., activation area) and centralized placement on the touch-sensitive display than other affordances  604 ,  606 ,  610 ,  612  displayed in the talk user interface  602  to promote ease of activation while preventing accidental touch inputs from activating the other affordances. 
     Further as shown at  FIG. 6AA , external device  699   a  is similar to device  600  and includes physically rotatable input mechanism  616   a  and/or physical push-button mechanism  618   a . The external device  699   a  displays a similar talk user interface  602   a  having similar elements and voice communication functionalities as the talk user interface  614  described above, including a contact affordance  604   a , talk affordance  606   a , visual indication  608   a , volume indicator  610   a , do-not-disturb toggle or switch  612   a , and current time  614   a . At device  699   a , the contact affordance  604   a  includes an image or headshot representation of John at device  600 , and the visual indication  608   a  indicates that the talk affordance  606   a , and in general that voice communications occurring at the displayed talk user interface  602   a  itself, is associated with John&#39;s device  600 . It is noted that while in the present examples the talk user interfaces  602 ,  602   a  are largely similar, in some examples, various aspects of their display such as color, orientation and placement of graphical elements and affordances can be altered or adjusted by user customization. For clarity sake in the depiction of the figures, reference lines and numerals for the elements and affordances described herein may not be repeatedly shown at every figure, although the elements and affordances may be included or displayed in accordance with the embodiments being shown in the figures. 
     In  FIG. 6AA , both devices  600  and  699   a  display the respective talk user interfaces  602 ,  602   a  indicating that they are both currently available and connected to a communication channel for voice communications with one another. For instance, in some examples, the talk user interface  602  is displayed at the device  600  only when both devices  600 ,  699   a  are currently available to capture voice inputs and send voice data corresponding to the voice inputs from the respective sending end to the respective receiving end where the received voice data is immediately and automatically output. In some examples, the communication channel is limited and dedicated to the devices  600 ,  699   a  only, such that additional external devices do not have access for connection to the communication channel. As described further below, in some examples the communication channel requires that each of the devices  600 ,  699   a  is directly connected to, and/or connected to via a relaying companion device, a communication network, such as a wireless communication networks described above, including Wi-Fi and cellular networks and Bluetooth connections. 
     Referring now to exemplary specifics of connections between devices,  FIG. 18  illustrates two possible communication pathways between device  1800  (e.g., device  600  in  FIG. 6AA ) and an external device  1802  (e.g., device  699   a  in  FIG. 6AA ) associated with a remote caller. In some examples, external device  1802  is directly connected to device  1800  such that data transmitted (or received) by external device  1802  is transmitted a direct communication channel  1808  between devices  1800  and  1802  without an intermediary companion device (e.g., device  1804 ). In this case, a real-time voice communication session (e.g., according to processes  900 ,  1000 ,  1100 ,  1200  and/or  1300  described below) is established directly between device  1800  and external device  1802   
     In other examples, external device  1802  is connected to device  1800  through companion device  1804 , which is paired to device  1800  (e.g., over WiFi or Bluetooth) In this case, a first voice communication session  1810  (e.g., a session according to processes  900 ,  1000 ,  1100 ,  1200  and/or  1300 ) is established between external device  1802  and companion device  1804 , while a relay voice communication session  1812  (e.g., a session according to processes  900 ,  1000 ,  1100 ,  1200  and/or  1300 ) is simultaneously established between companion device  1804  and device  1800 . Data received from external device  1802  through the first voice communication session  1810  may then be relayed to device  1800  using the relay voice communication session  1812 . 
     In some embodiments, device  1800  and companion device  1804  may have multiple call kits that handle different types relay communication sessions between the two devices. For example, device  1800  and companion devices have standard call kits for a first type of communication session (e.g., a FaceTime Audio™ call or standard telephone call). This standard call kit may be made apparent by the user (e.g., by showing a banner notification on companion device during a call and other notification related to the call kit) and may be visible to other applications on device  1800  and companion device  1804  by their respective application program interfaces (APIs). However, the relay communication sessions of processes  900 ,  1000 ,  1100 ,  1200 , and/or  1300  may be handled by a special call kit on device  1800  and companion device  1804 . This special call kit may not provide any notifications on companion device  1804  and may be hidden from some or all other applications on companion device  1804  by its API, even if the data transmitted over the relay communication session is the same as a standard call. Since the special call kit handling voice communication sessions according to methods  900 ,  1000 ,  1100 ,  1200  and/or  1300  is less visible to companion device  1804  in one or more ways, a direct communication session between device  1800  and external device  1802  may present to the user in the same way as a relayed communication session involving companion device  1804 . 
     In some embodiments, companion device  1804  is, optionally, configured to communicate over multiple radio access technologies (e.g., both WiFi and a cellular network, similar to mobile device  1700  of  FIG. 17 ). In this case, companion device  1804  establishes the first voice communication session  1810  with external device  1802  on a primary communication channel using a first RAT (e.g., WiFi), and a secondary (redundant) communication channel with external device  1802  using a second RAT (e.g., a cellular network). In response to a deterioration or degradation in uplink quality on the primary communication channel (e.g., excessive data packet loss, latency issues, etc.), companion device  1804  optionally establishes the secondary communication channel to transmit voice and/or control data to external device  1802  in place of the primary communication channel. This ensures, under some circumstances, higher quality communications between device  1800  and external device  1802 , as well as prevent dropped and interrupted sessions. 
     Optionally, companion device also establishes an additional voice communication session with a third device  1806 , which may be a computer, TV, or any other suitable type of electronic device. 
     Turning now to  FIG. 6AB , while devices  600 ,  699   a  are connected to the communication channel, device  600  detects a touch input  620  on talk affordance  606 . In some examples, the touch input  620  is a press-and-hold gesture as described above. In some examples as shown at  FIG. 6AB , in response to detecting the touch input  620  at talk affordance  606 , device  600  issues a perceptual output  622  including a haptic output and/or audible output. In practice, perceptual output  622  contributes to simulation of a walkie-talkie communication experience and is issued prior to activating the microphone at device  600  and/or prior to capturing voice input at the microphone, thereby indicating to John that he is live, and that voice input is about to be captured and transmitted to Jane&#39;s external device  699   a.    
     Turning now to  FIG. 6AC , in some examples as shown at  FIG. 6AC , a visual input indication  624  is displayed in response to detecting the touch input  620 . For example, visual input indication  624  is displayed during and/or immediately following issuing the perceptual output  622 . The visual input indication  624  provides visual feedback that the talk affordance  606  is activated, and in other words the device  600  is capturing (e.g., registering) any voice inputs detected at the microphone and concurrently sending the voice data corresponding to the voice input to external device  699   a  for the duration of the activation. For example, as shown in  FIGS. 6AC to 6AF , visual input indication  624  is displayed for the duration of the touch input  620  while John is speaking out loud, where John&#39;s speech is being captured at the microphone and sent to external device  699   a . In the current example, visual input indication  624  is an animation of ripples emerging from the talk affordance  606  and/or circles circling the talk affordance  606 . Additionally and/or alternatively, visual input indications can include altering a color of the talk affordance  606  and/or the background of the talk user interface  602  during the activation to distinguish the talk affordance  606  from the inactivated state. As shown at  FIGS. 6AB to 6AF , touch input  620  remains on talk affordance  606  for the duration of the activation and upon detecting liftoff of the sustained touch input  620  at  FIG. 6AG , activation of talk affordance  606  ceases. When talk affordance  606  is no longer activated, visual input indication  624  disappears, indicating device  600  is not currently capturing voice input and sending voice data to external device  699   a , and in some cases turns off the microphone at device  600 . In further examples, device  600  issues another perceptual output upon detecting liftoff or deactivation of the talk affordance  606  to further indicate that voice input is no longer being captured and outgoing data is no longer being sent from device  600 . 
     Turning back to  FIG. 6AB , Jane&#39;s external device  699   a  receives an indication from John&#39;s device  600  that talk affordance  606  at John&#39;s device  600  has been activated. In response, external device  699   a  issues perceptual notification  626   a , which includes a haptic output and/or audible output. In some cases, perceptual notification  626   a  includes both haptic and audible outputs issued simultaneously (e.g., vibration and ding). In practice, perceptual notification  626   a  indicates that incoming voice data through the communication channel is being received and is soon to be output, automatically, at speakers at device  699   a . In some examples, perceptual notification  626   a  is similar to perceptual output  622  issued at John&#39;s sending device  600  in response to the activation, and/or occurs simultaneously or near-simultaneously at both devices  600 ,  699   a , depending on network latency and other factors. In some examples, perceptual notification  626   a  is distinct from perceptual output  622 , and/or perceptual notification  626   a  is unique to the sending contact, such that the user at the receiving end can immediately distinguish the source of the incoming voice data without visually observing the talk user interface  602   a . In some examples, perceptual notification  626   a  contributes to simulation of a walkie-talkie communication experience and is issued prior to initiating audio output corresponding to the incoming voice data itself, thereby providing an indication to Jane that voice data is being received and output thereof is about to occur. 
     Referring now to exemplary specifics of signal exchange from the perspective of device  699   a , device  600  and device  699   a  are connected through a live audio communication in the example shown in  FIGS. 6AA to 6AC  (e.g., when both devices display talk user interfaces). The live audio communication session occupies one or more communication channels and is configured to transmit control signal data as well as media (e.g., audio) data between devices  600  and  699 . In the embodiment of  FIG. 15 , the live audio communication session occupies a control channel  1502  and a separate media channel  1506  connecting devices  600  and  699   b . For example, media channel  1506  is, optionally, a VoIP channel that transmits live audio data according to the Real-Time Transmission Protocol (RTP) standard. In this case, control channel  1502  is, optionally, a separate VoIP channel that transmits control signal data according to the Real-Time Transmission Control Protocol (RTCP) standard. In some embodiments, the live audio communication session between John&#39;s device  600  and Jane&#39;s device  699  is established before either talk affordance  606  or talk affordance  606   a  can be activated. 
     Referring still to the waveform diagram of  FIG. 15 , device  699   a  receives control signal data  1504  from external device  600  over control channel  1502  at some point after the live audio communication session has been established. In some embodiments, the control signal data  1504  is transmitted to device  699   a  when the user activates talk affordance  606  on device  600 . In the example discussed above, control signal  1504  is, optionally, encoded in the application-specific data of a Real-Time Transfer Control Protocol (RTCP) signal. In the example of  FIG. 15 , control signal  1504  presents as a rising signal edge on control channel  1504  (e.g., signal goes high from a default-low state). In other embodiments not shown, control signal  1504  optionally presents as an interruption in a steady-state high signal (e.g., a falling signal edge on control channel  1502 ). 
     In response to receiving control signal data  1504 , device  699   a  issues a perceptual notification (such as notification  626   a ) to the user. The perceptual notification is, optionally, an audio, visual, or haptic alert, or any combination thereof. As discussed above in connection with  FIG. 6AB , under some circumstances, the perceptual notification indicates to a user of device  699   a  that the talk affordance on the external device (e.g., talk affordance  606  on device  600 ) has been activated and that corresponding audio data is incoming. 
     Referring still to  FIG. 15 , device  699   a  receives audio data  1510  from device  600  over media channel  1506  after receiving control signal data  1504 . In the example of  FIG. 15 , voice audio data  1510  is provided in a digital data stream that encodes a voice signal (e.g., the voice signal picked up by the microphone (e.g., microphone  113 ) on external device  600  after activating talk affordance  606 ) and is interspersed in an existing audio data stream transmitted over media channel  1506 . In the case of a full-duplex audio session, baseline audio data  1508  (e.g., a baseline signal from a muted microphone) is, optionally, still transmitted on media channel  1506  even though it does not encode a voice signal recorded at device  600 . In this case, baseline audio data is optionally transmitted at a lower bit rate than audio data  1510 , which encodes a voice signal. Audio data  1510  and baseline audio data  1508  is optionally compressed using MPEG, AWS, EVS, ACELD, or any other audio codec suitable for real-time applications. In the embodiment of  FIG. 15 , there is a predetermined time period  1512  between receiving control signal data  1504  and receiving voice audio data  1510 . This predetermined time period may be 100 ms, 150 ms, 250 ms, 500 ms, 1 s, or another other suitable time period. 
     After issuing the perceptual notification and receiving voice audio data  1510 , device  699   a  outputs voice audio data from a speaker (e.g., speaker  111 ). In some examples, voice audio data  1510  is transcoded or otherwise converted into analog sound or voice signals prior to output. In some embodiments, there is a second predetermined time period between issuing the perceptual notification and playing back voice audio data  1510 . This second predetermined time period may be 100 ms, 150 ms, 250 ms, 500 ms, 1 s, or another suitable time period. In one such embodiment, the predetermined time period between receiving the control signal and receiving the audio data is the same duration as the predetermined time period between issuing the perceptual notification and outputting the audio data. In other embodiments, the first predetermined time period is a different duration than the second predetermined time period. 
     In some embodiments, device  699   a  is configured to disable audio input to its microphone (e.g., microphone  113 ) in response to receiving control signal data  1504 . In one such embodiment, receiving control signal data  1504  disables talk affordance  606   a , thereby preventing the user of device  699   a  from activating the microphone. In another such embodiment, device  699   a  optionally mutes its uplink connection to media channel  1506  in response to receiving the control signal, thereby preventing audio data from being sent to device  600 . Since control signal data  1504  is received before incoming voice audio data  1510 , disabling audio input to the microphone in this manner effectively prevents device  699   a  from sending voice audio data to device  600  immediately prior to receiving and during playback of incoming voice audio data  1510 . Thus, even if the live audio communication session is a full-duplex connection between devices  699   a  and  600  (e.g., the session allows sending and receiving audio data simultaneously), disabling audio input in response to the control signal allows, in some cases, only one of devices  699   a  and  600  to transmit audio data at any given time. Alternatively or additionally, device  699   a  optionally does not transmit audio data on media channel  1506  while audio data  1510  is being received (e.g., device  699   a  mutes its uplink to media channel  1506 ). The microphone, the transmitter, the analog-to-digital converter associated with the transmitter and/or the audio codec associated with the transmitter on device  699   a  are, optionally, also powered down while receiving audio data  1510 , lowering or eliminating power on media channel  1506  and/or control channel  1510 . This configuration, in some embodiments effectively simulates a half-duplex connection (similar to the connection between two conventional walkie-talkie devices) in a full-duplex environment while also conserving power on device  699   a.    
     In some embodiments, audio input to the microphone is optionally disabled for a predetermined time period in response to receiving the control signal. In other embodiments, audio input to the microphone is disabled until an additional control signal is received. The additional control signal, in some cases, indicates that transmission of audio data  1510  is complete, and is optionally generated in response to deactivation of the talk affordance (e.g., talk affordance  606 ) on the sending device. In other embodiments, audio input to the microphone is disabled in response to receiving control signal  1504  until the speaker on the receiving device (e.g., speaker  111  on device  699   a ) finishes outputting the accompanying voice audio data  1510 . 
     As discussed below in connection with  FIGS. 6EA and 6EB , devices  600  and/or  699   a  optionally suppresses perceptual notifications (e.g., alert banners, audio alerts, and haptic alerts) from external applications (e.g., outside notification  664   a ) for some or all of the time in which the live audio communication session is active. In particular, device  699   a  optionally forgoes issuing perceptual notifications from applications other than the application associated with the talk user interface in response to receiving control signal  1504 . In some embodiments, notifications from other (e.g., external) applications are suppressed for a predetermined time period after receiving control signal  1504 . Perceptual notifications from other applications suppressed in response to the control signal optionally include audio, visual and/or haptic alerts corresponding to receipt of a text message, e-mail alert, and so on. In some cases, the suppressed perceptual notifications are then issued after the predetermined time period elapses or after the live audio communication session between devices  600  and  699   a  is terminated. 
     In the example of  FIG. 15 , device  699   a  receives control signal data  1504  on control channel  1502  and receives audio data  1510  on a separate media channel  1506 . In this case, the live audio communication session is allocated two separate communication channels for exchanging control and audio data. It should be appreciated that this example is merely illustrative. In other embodiments, control signal data (e.g., control signal data  1504 ) and audio data (e.g., audio data  1510 ) are received by device  699   a  on the same communication channel. For example, the audio data optionally contains a stream of audio data packets, each with a header (e.g., non-audio encoding information) and a payload that encodes a voice signal. In such embodiments, the control signal data is, optionally, encoded in the header of one or more data packets in the audio data steam (e.g., the first packet in the audio data stream). As an example, if audio data is transmitted to device  699   a  according to the RTP standard, the corresponding control signal data is, optionally, encoded in the RTP extension header of the first RTP packet in the audio data stream. Alternatively or additionally, if audio data is transmitted to device  699   a  according to the TCP standard, the corresponding control signal data is, optionally, encoded in the TCP extension header of the first TCP packet in the audio data steam. 
     While the above discussion of  FIG. 15  mentions RTP as a possible signaling standard for exchanging audio data  1510  on media channel  1506 , it should be appreciated that any VoIP standard suitable for transmission of real-time audio data between two devices can be used. In other embodiments, audio data is transmitted according to the Secure Real-Time Transfer Protocol (SRTP), Universal Datagram Protocol (UDP), Transmission Control Protocol (TCP), FaceTime Audio™, or any other signaling standard suitable for real-time media communications. 
     Similarly, while the above discussion of  FIG. 15  mentions RTCP as a possible signaling standard for exchanging control signal data  1504  on control channel  1502 , it should be appreciated that any VoIP standard suitable for transmitting signaling data in a real-time media communication session can be used. In other embodiments, control signal data is transmitted according to the Session Initiation Protocol (SIP), Real-Time Transfer Protocol (e.g., in an RTP extension header), Transmission Control Protocol (e.g., in a TCP extension header), or any other signaling standard suitable for exchanging control signals related to real-time media communications. 
     In some examples as shown at  FIGS. 6AC to 6AF , visual output indication  628   a  is displayed at external device  699   a  during and/or immediately following issuing the perceptual output  622  and during audio output  630   a  of the voice data received from John. The visual output indication  628   a  provides visual feedback that John is activating the talk affordance  606  at his device  600 , and that voice data corresponding to John&#39;s voice input is being sent to external device  699   a  and is being output. In some examples, visual output indication  628   a  is displayed for the duration of the audio output  630   a , as shown through  FIGS. 6AC to 6AF  and disappears when John ceases activation of the talk affordance  606  at  FIG. 6AG  when John finishes talking. At  FIG. 6AG , voice data is no longer being received at external device  699   a  since activation of the talk affordance  606  at sending device  600  has ceased. In the current example, visual output indication  628   a  is an animation of ripples emerging from the contact affordance  604   a  and/or animated circles at the contact affordance  604   a , and/or similar to the visual input indication  624 . Additionally and/or alternatively, visual output indications can include altering a color of contact affordance  604   a  and/or the background of the talk user interface  602   a  during the activation. In further examples, the external device  699   a  issues an end-of-message perceptual notification including a haptic output and/or audible output to indicate an end of the audio output  630   a  and/or serve as indication to Jane that the communication channel is now open for her to respond to John. 
     As shown at  FIGS. 6AD to 6AE , a volume level of the audio output  630   a  of voice data is adjustable at external device  699   a  while outputting the voice data. In the present example at  FIG. 6AD , rotational input  632  received at the rotatable input mechanism  616   a  decreases the volume level of audio output  630   a , as reflected in the decreased audio output  630   a  of  FIG. 6AE . A rotational input in the opposite direction of rotational input  632  increases the volume level. The volume indicator or volume icon  610   a  is animated in accordance with the rotational input  632  to reflect the adjusted volume level. In some examples, the volume level is decreased to a minimum level at the external device  699  such that external device  699   a  receives voice data and outputs audio corresponding to the voice data at a volume level that cannot be heard by the user, while visual output indication  628   a  is still displayed and perceptual notification  626   a  is still issued. The volume level remains at the adjusted volume level for at least a duration of a talk session between the users at the communication channel, in some embodiments, as shown through at the volume icon  610   a  through  FIGS. 6AE to 6AI . 
     As further at  FIGS. 6AG to 6AI , at  FIG. 6AG  John finishes talking at device  600  and both devices  600 ,  699   a  display their respective talk user interfaces  602 ,  602   a , indicating that the communication channel is open and no voice data is currently being communicated at the channel. At  FIG. 6AH , Jane responds to John&#39;s message by touch input  620   a  at talk affordance  606   a . In response to detecting touch input  620   a , external device  699   a  issues a perceptual output  622   a  (similar to perceptual output  622 ) and signals John&#39;s device  600  that talk affordance  606   a  has been activated at the external device  699   a . In response, John&#39;s device  600  issues perceptual notification  626  (similar to perceptual notification  626   a ). At  FIG. 6AI , Jane&#39;s external device  699   a  detects voice input from Jane and transmits the voice data to John&#39;s device  600 , causing audio output  630  of Jane&#39;s voice data while displaying visual output indication  628  (similar to visual output indication  628   a ) at the contact affordance  604  representing Jane, indicating that Jane is talking and audio is being output. Meanwhile at Jane&#39;s external device  699   a , visual input indication  624   a  (similar to visual input indication  624 ) is displayed at talk affordance  606   a  while touch input  620   a  is detected at the talk affordance  606   a , indicating that device  699   a  is capturing Jane&#39;s voice input at the microphone at device  699   a  and transmitting voice data corresponding to the voice input to device  600 . It is contemplated that due at least in part to the immediateness of the voice communications described herein, where voice inputs at one end are immediately sent for automatic output at the receiving end, the voice communications techniques and user interfaces presented herein offer a heightened personal form of holding conversation through electronic communications. 
     Referring now to the specifics of transmitting voice audio data to an external device from the perspective of device  699   a , device  600  and device  699   a  are still connected through the live audio communication in the example shown in  FIGS. 6AG to 6AI  (e.g., when both devices display talk user interfaces). In the embodiment of  FIG. 16 , the live audio communication session occupies a control channel  1602  and a separate media channel  1606  connecting devices  600  and  699   a . Control channel  1602  and media channel  1606  are, optionally, the same communication channels as control channel  1502  and  1506  shown in  FIG. 15 , respectively. In some cases, control channel  1602  is different from control channel  1502  and/or media channel  1606 , in some cases, is different from media channel  1506  (e.g., if the audio communication session between device  600  and  699   a  is dropped and subsequently re-established). 
     Referring to the example of  FIG. 16 , control signal data  1604  is transmitted to device  600  over control channel  1602  and audio input to the microphone (e.g., microphone  113 ) on device  699   a  is enabled. The audio input to the microphone is, optionally, enabled in response to receiving a user input at device  699   a  (e.g., user touch  620   a  that activates talk affordance  606   a ). In some embodiments, audio input to the microphone is enabled only if the user input is detected prior to receiving a control signal (e.g., control signal  1504 ) from device  600  or after playback of audio data sent by device  600  (e.g., voice audio data  1510 ) has finished. In response to an appropriate user input, device  699   a  outputs control signal data  1604  to device  600  on control channel  1602 . As discussed above in connection with  FIG. 15 , control signal data  1604 , in some cases, notifies device  600  that associated audio data (e.g., audio data  1610 ) is incoming. In some embodiments, audio input to the microphone on device  699   a  is enabled a predetermined time period after receiving the user input. This predetermined time period may be 100 ms, 150 ms, 250 ms, or any other suitable time period. 
     After outputting control signal data  1604  to device  600 , device  699   a  outputs voice audio data  1610  to device  600  over media channel  1606 . In the example of  FIG. 16 , voice audio data  1610  is a digital data stream that encodes a voice signal (e.g., the voice signal picked up by the microphone (e.g., microphone  113 ) on device  699   a  after activating talk affordance  606   a ) and is interspersed in an existing audio data stream transmitted over media channel  1606 . In the case of a full-duplex audio session, baseline audio data  1608  (e.g., a baseline signal from a muted microphone) is, in some cases, still transmitted on media channel  1606  even though it does not encode a voice signal. In this case, baseline audio data is, optionally, transmitted to device  600  at a lower bit rate than voice audio data  1610 . Alternatively and/or additionally, device  699   a  optionally does not receive audio data on media channel  1606  while audio data  1610  is being transmitted (e.g., device  699   a  mutes its downlink on media channel  1606 ). In some embodiments, the speaker, the receiver, the digital-to-analog converter associated with the receiver and/or the audio codec associated with the receiver on device  699   a  are also powered down while transmitting audio data  1510 . 
     In some examples, voice audio data  1610  and baseline audio data  1608  are compressed using MPEG, AWS, EVS, ACELD, or any other audio codec suitable for real-time applications. In the embodiment of  FIG. 16 , there is a predetermined time period  1612  between sending control signal data  1604  and sending voice audio data  1610 . This predetermined time period may be 100 ms, 150 ms, 250 ms, 500 ms, 1 s, or any other suitable time period. This predetermined time period may or may not be the same as the predetermined time period between receiving the user input that activates talk affordance  606   a  and enabling audio input to the microphone. 
     In the example of  FIG. 16 , device  699   a  sends control signal data  1604  on control channel  1602  and sends audio data  1610  on a separate media channel  1606 . In this case, the live audio communication session is allocated two separate communication channels for exchanging control and audio data. It should be appreciated that this example is merely illustrative. In other embodiments, control signal data (e.g., control signal data  1604 ) and audio data (e.g., audio data  1610 ) is, optionally, sent by device  699   a  on the same communication channel. For example, the audio data optionally contains a stream of audio data packets, each with a header (e.g., non-audio encoding information) and a payload that encodes a voice signal. In this case, the control signal data is, optionally, encoded in the header of one or more data packets in the audio data steam (e.g., the first packet in the audio data stream). As an example, if audio data is transmitted to device  600  according to the RTP standard, the corresponding control signal data is optionally encoded in the RTP extension header of the first RTP packet in the audio data stream. Alternatively and/or additionally, if audio data is transmitted to device  600  according to the TCP standard, the corresponding control signal data is optionally encoded in the TCP extension header of the first TCP packet in the audio data steam. 
     Referring back to  FIGS. 6AG through 6AI , it is contemplated that the foregoing described visual indications  624 ,  624   a ,  628 ,  628   a , displayed at the affordances  604 ,  604   a ,  606 ,  606   a , indicate when the communication channel is occupied in sending/receiving voice data and when the communication channel is free. In some examples, the live audio communication session is a full-duplex communication session whereby both ends can send and receive voice data at the same time. In some examples, the live audio communication channel is a half-duplex communication session where the communication channel permits bidirectional communication but only in one direction of flow at a single time. In some examples, the live audio communication session permits duplex communication, but the talk affordances  606 ,  606   a  cannot be activated when their respective devices  600 ,  699   a  have received indication that the other device  600  or  699   a  has already activated the respective talk affordance  606  or  606   a , until the receiving device  600  or  699   a  receives a subsequent indication that activation of the talk affordance  606 ,  606   a  at the opposing end has stopped. In some examples, the talk affordance  606 ,  606   a  regulates flow of communication signals in the communication channel. 
     As discussed above in connection with  FIG. 15 , the receiving device (e.g., device  600  or  699   a ) optionally prevents audio input to its microphone in response to receiving control signal data (e.g., control signal  1504  or control signal  1604 ), even in a full-duplex connection. If talk affordances  606  and  606   a  are activated on both devices at roughly the same time, the receiving device (e.g., device  600 ), in some cases, detects user activation of the talk affordance before receiving control signal data  1604 , but after the talk affordance on the sending device (e.g., device  699   a ) was activated. This timing conflict is, in some cases, caused by latency, the non-instantaneous nature of signal transmission, or a number of other factors. In these cases, it is necessary to determine whether the talk affordance of the receiving device was activated before the control signal data was generated by the sending device. The result then determines which device transmits audio data over media channel  1606  and which device&#39;s audio output is disabled. 
     In some embodiments, resolving conflicts between incoming and outgoing control signals is, optionally, done at the network server (e.g., network  1702  of  FIG. 17 ). In the example above, determining if the user input that activated talk affordance  606   a  occurred before the incoming control signal (e.g., control signal  1504 ) was generated is, optionally, based on clocking data contained in the incoming control signal and/or the outgoing control signal (e.g., control signal  1604 ). In some embodiments, the clocking data is a time stamp specifying the absolute time (e.g., time elapsed since a time predetermined by the signaling standard) at which the control signal was generated. In other embodiments, the clocking data is a time stamp specifying the time elapsed since the audio communication session between devices  600  and  699   a  was established. Generally, this determination is performed in response to receiving the user input activating talk affordance  606   a  a predetermined time before receiving control signal data  1504 . For example, the conflict determination is optionally performed if the time difference between the time-stamp of the incoming control signal (e.g., control signal  1504 ) and the time-stamp of the outgoing control signal (e.g., control signal  1604 ) is less than the average signal transmission time between devices  600  and  699   a . In other embodiments, the conflict determination is performed directly by device  699   a  and/or device  600  (e.g., by comparing the time-stamp on the incoming control signal to the time at which the talk affordance was activated). 
     In accordance with a determination that the user input to activate talk affordance  606   a  occurred before the incoming control signal was generated, device  699   a  optionally enables audio input to its microphone and/or forgoes outputting incoming audio data (e.g., voice audio data  1510 ) from its speaker. This allows device  699   a  to transmit voice data to device  600  even though the talk affordance on device  600  has been activated at roughly the same time. However, in accordance with a determination that the user input to activate talk affordance  606   a  occurred after the incoming control signal was generated, device  699   a  optionally prevents audio input to its microphone and/or output incoming audio data from its speaker. In this case, device  699   a  receives and plays back voice data even though the talk affordance on device  699   a  has been activated at roughly the same time. 
     Returning to a discussion of user interface flow,  FIGS. 6BA to 6BD  illustrate stopping audio output of incoming voice data before it is automatically output, and/or before initiating its automatic output. For example, at  FIG. 6BA , John&#39;s touch-sensitive display screen at device  600  is in an off state. At  FIG. 6BB , Jane&#39;s device  699   a  detects touch input  620   b  at talk affordance  606   a , which causes issuance of the perceptual output  622   a  at Jane&#39;s device  699   a  and signals John&#39;s device  600  of the activation. John&#39;s device  600  receives the signal indication and issues perceptual notification  626 . In the present example, John&#39;s display screen remains off during issuance of perceptual notification  626 , while in some examples the display screen turns on from the off state and/or immediately initiates display of the voice communication application. At  FIG. 6BC , a quiet gesture  638  is detected at John&#39;s device  600  after issuing the perceptual notification  622 . In some examples, the quiet gesture  638  is a palm-to-display gesture in which a user covers a majority of the display screen  636  with the user&#39;s palm. In the present example, the device  600  detects that the quiet gesture  638  is received within a predetermined delay period after issuing the perceptual notification  626  and prior to initiating audio output of the voice data. When the quiet gesture  638  is detected within the predetermined delay period, device  600  foregoes outputting the audio data, as shown at  FIG. 6BD . In the present example, the quiet gesture  638  maintains the off state at display screen and/or turns the display screen to the off state. In some examples, upon detecting quiet gesture  638 , the device  600  responds to the external device  699   a  that the receiving device  600  is not available for voice communications at this time. In some examples, device  600  drops the communication channel in response to quiet gesture  638 . 
     At  FIG. 6BD , in response to receiving indication at external device  699   a  that the receiver is unavailable, device  699   a  transitions from displaying talk user interface  602   a  at  FIG. 6BC , which in the present example includes visual input indication  624   a  indicating activation of talk affordance  606   a  in response to touch input  620   b , to a contact unavailable screen  640   a . In the present example, the contact unavailable screen  640   a  is a shaded or otherwise greyed-out screen that includes a visual representation  642  of the contact that is unavailable, such as an image, monogram, and/or affordance representing the contact (in this case, John&#39;s image) and brief text indicating the contact&#39;s unavailability (e.g., “John is unavailable”). In some examples, contact unavailable screen  640   a  includes add affordance that can be selected (e.g., with a tap input) to display a contact list for connecting to another contact, and in some cases to permit the user to attempt to reconnect to the currently unavailable contact. As discussed further below, in some examples, quiet gesture  638  at device  600  causes device  600  to enter a temporary do-not-disturb mode for a predetermined period of time during which no voice communications via the voice communication application from any contacts are received for output at the device  600 . In such cases, device  600  automatically exits the do-not-disturb mode upon lapse of the predetermined period of time to resume normal operation at the voice communication application. 
       FIGS. 6CA to 6CE  illustrate stopping audio output of the voice data while the voice data is being output at the receiving device  600 . As shown at  FIGS. 6CA to 6CB , John&#39;s display screen at device  600  is off (e.g., off, asleep, screensaver, dark). John&#39;s device  600  issues perceptual notification  626  in response to receiving an indication that external device  699   a  has activated, via touch input  620   c , the talk affordance  606   a . Since a quiet gesture (e.g., quiet gesture  638 ) is not detected during the predetermined delay period after issuing the perceptual notification  626 , device  600  automatically proceeds with causing audio output  630  of voice data that is received from external device  699   a , as shown at  FIG. 6CC .  FIGS. 6CB to 6CC  further illustrate that upon initiating audio output  630  and during audio output  630 , John&#39;s display screen is turned on to display the talk user interface  602  associated with the contact of the incoming voice data, as indicated at the contact affordance  604  representing Jane. As shown at  FIG. 6CD , during audio output  630 , in response to receiving quiet gesture  638 , the device  600  ends audio output  630  and stops receiving voice data from external device  699   a.    
     From  FIGS. 6CD to 6CE , device  600  transitions the display screen from the on state to the off state, as shown at  FIG. 6CE . Further in response to quiet gesture  638 , device  600  indicates to external device  699   a  (e.g., by sending a signal and/or by way of dropping the communication channel at device  600  when quiet gesture  638   a  is received) that the receiver is unavailable. In response to detecting John is unavailable and/or otherwise that communication channel is no longer available, external device  699   a  automatically transitions from the talk user interface  602   a  at  FIG. 6CD  to the contact unavailable screen  640   a  having the visual representation  642  showing John&#39;s image and text indicating that John is unavailable. As shown in  FIGS. 6CD to 6CE , the transition from talk user interface  602   a  to contact unavailable screen  640   a  occurs while touch input  620   c  is detected at talk affordance  606   a  and while Jane&#39;s voice input is being captured at device  699   a . In this way, in response to detecting that device  600  is unavailable, device  699   a  interrupts the capturing of voice input and the sending of voice data to device  600 . It is noted that in some cases, device  699   a  does not immediately know when device  600  becomes unavailable, until a subsequent activation of talk affordance  606   a  attempts to reach device  600  and the attempt is unsuccessful. 
     Turning now to  FIGS. 6DA to 6DE , in some examples, John&#39;s device  600  is in a do-not-disturb mode where no voice communications can be sent and/or received at the voice communications application on device  600 . In some examples, voice communications from a particular contact, e.g., a contact corresponding to the source of the voice data when the quiet gesture  638  is detected, are blocked while other contacts can optionally send voice data to the device  600  via other communication channels. In some examples, voice communications from any contact are blocked at the voice communication application during the do-not-disturb mode. In some cases, device  600  responds to any incoming voice data with an indication that device  600  is unavailable and does not store any alert or indication that an attempt to reach device  600  occurred during the unavailable state. It this case, without indication of missed voice communications and/or without saving incoming voice data for later retrieval, it is contemplated that the voice communications described herein provide an ephemeral form of personal communications through electronic communications 
     As mentioned above, in some cases, detection of quiet gesture  638  causes device  600  to enter a temporary do-not-disturb mode for a predetermined period of time before automatically exiting the temporary do-not-disturb mode to resume voice communications. Entering the temporary do-not-disturb mode automatically toggles the do-not-disturb toggle switch  612  (e.g., as shown at  FIG. 6AA  in an on position) to an off position and can be manually toggled to an on position prior to lapse of the predetermined period of time, in some embodiments. 
     For example at  FIG. 6DA , John&#39;s device  600  is in temporary do-not-disturb mode in response to quiet gesture  638  of  FIGS. 6BA to 6BD  or  FIGS. 6CA to 6CE . At  FIG. 6DA , activation input  648  such as a press on the rotatable input mechanism  616  turns display screen on and transitions to a home screen  650  that includes a plurality of application launch icons, including a voice communication application launch icon  652 . Application launch icons when selected launch their corresponding underlying applications. In response to detection of touch input  654  on the voice communication application launch icon  652  at  FIG. 6DB , device  600  launches the voice communication application and displays do-not-disturb screen  656  at  FIG. 6DC . In the present example at  FIG. 6DC , the do-not-disturb screen  656  is a greyed-out screen that includes a visual representation  642  of the last contact that was in communication via the voice communication application (e.g., an image of Jane) prior to entering do-not-disturb mode, and includes toggle switch  612  as shown in an off position. In response to detecting touch input  660  at the toggle switch  612  (off position) at  FIG. 6DD , device  600  transitions from the do-not-disturb screen  656  to displaying the talk user interface  602  corresponding to the last contact that was in communication, as represented at the contact affordance  604  which shows Jane&#39;s image (e.g., visual representation  642  for Jane). At  FIG. 6DE , the toggle switch  612  is displayed in the on position in the talk user interface  602 . In some cases, the talk user interface  602  is displayed only when the last contact is still available for voice communications at the time after toggling back on. In some cases if the last contact is unavailable when device  600  toggles back on, device  600  displays a contact unavailable screen corresponding to the last contact (e.g., with Jane&#39;s image) upon toggling back on. 
     Further, in some examples when the device  600  automatically exits the do-not-disturb mode based on lapse of the predetermined period of time, upon detection of touch input  654  on the voice communication application launch icon  652  at  FIG. 6DB , device  600  launches the voice communication application and displays the talk user interface  602  with switch  612  in the on position if the last contact is still available, without displaying do-not-disturb screen  656 . 
     Shown further in  FIGS. 6DA to 6DE , external device  699   a , when in the voice communication application, displays the contact unavailable screen  640   a  for the contact when the contact is toggled off. For example, at  FIGS. 6DA to 6DD , external device  699   a  displays contact unavailable screen  640   a  (e.g., John&#39;s image and “John is unavailable”) and automatically transitions back into talk user interface  602   a  at  FIG. 6DE  upon detecting that the communication channel with the contact is available again, and/or otherwise upon receiving an indication that John&#39;s device  600  is available for voice communications. At  FIG. 6DE , John and Jane are able to send and receive voice data through the communication channel as discussed in the techniques above using talk affordances  606 ,  606   a  at their respective talk user interfaces  602 ,  602   a.    
       FIGS. 6EA to 6EB, 6FA to 6FF, 6GA to 6GF, and 6HA to 6HH  illustrate examples for handling incoming notifications during voice communications at the voice communications application. In some examples, notifications are suppressed at the device  600  or  699   a  while displaying the talk user interface  602  or  602   a , and/or only while the talk affordance  606  or  606   a  is being activated, and/or only while receiving incoming voice data and outputting voice data  630  or  630   a , and/or not suppressed at all, and/or any combination thereof. In some cases, handling incoming notifications is customized by user settings. In some cases when incoming notifications are suppressed, the incoming notifications are stored in a notifications drawer and accessible for later retrieval (e.g., via a notifications module). In other examples, incoming notification(s) are queued for output at a later time (e.g., when talk user interface  602  or  602   a  is no longer displayed, when talk affordance  606  or  606   a  is no longer being activated, and/or when voice data is not currently being output). 
     For example, at  FIGS. 6EA to 6EB , both devices  600 , 699   a  are connected to a voice communication channel for sending and receiving voice communications with one another via their respective talk user interfaces  602 ,  602   a . In  FIG. 6EA , incoming notification  664   a  is received at device  600 . The incoming notification  664   a  corresponds to a notification or alert from another application at the device  600 , incoming text message, email alert, and so on. In the present example, incoming notification  664   a  is suppressed or otherwise not output for display, as shown at  FIG. 6EB  which continues to display talk user interface  602 . In practice, suppressing notifications from being displayed and/or otherwise from being perceptually output allows voice communication sessions to be uninterrupted. In some examples, only notifications having priority status are displayed and permitted for output during the voice communications. 
     Turning now to  FIGS. 6FA to 6FF , in an example shown at  FIGS. 6FA to 6FF , initially, both devices  600 , 699   a  are connected to a voice communication channel for sending and receiving voice communications with one another via their respective talk user interfaces  602 ,  602   a . In  FIG. 6FA , incoming notification  664   a  is received at device  600  and, instead of being suppressed, is displayed at  FIG. 6FB  showing notification alert  666   a . For example, the notification alert  666   a  is permitted to appear when talk user interface  602  is displayed while talk affordance  606  is not activated and/or device  600  is not actively receiving audio data from external device  699   a . As shown at  FIGS. 6FB to 6FC , display of notification alert  666   a  does not exit the voice communication application or otherwise cause device  600  to be unavailable, and external device  699   a  continues display of talk user interface  602   a  associated with communicating with device  600 . In the current example, notification alert  666   a  corresponds to an incoming email and displays a portion of the notification, (e.g., “Your order has been shipped!”), an indication  668  of the application corresponding to the notification, an application launch affordance  670  (also referred to as “view affordance”  670 ) and a dismiss notification affordance  672  (also referred to as “dismiss affordance”  672 ). At  FIG. 6FC , device  600  detects touch input  674   a  on dismiss notification affordance  672  to remove display of notification alert  666   a  and resume display of talk user interface  602  at  FIG. 6FD . In some examples, notification alert  666   a  is displayed briefly and automatically disappears without user selection of dismiss affordance  672 . 
     In another example, at  FIG. 6FE , touch input  674   b  is detected on launch affordance  670  of the notification alert  666   a , which causes the mail application to launch and display a remainder of the incoming notification (e.g., the full email) in a mail application user interface  666   b . As shown at  FIG. 6FF , launching the mail application causes the mail application to be the active application and therefore leaves the voice communication application and/or ends connection to the voice communication channel associated with external device  699   a . In response to an indication that the communication channel with device  600  is no longer available, external device  699   a  transitions display from talk user interface  602   a  at  FIG. 6FE  to contact unavailable screen  640   a . In some examples, connection with device  600  can be re-initiated or attempted to be re-initiated by device  699   a  via the add affordance  644  and subsequent selection of the same contact (e.g., John) from the contact list, as discussed further below. It is noted that in some examples, external device  699   a  continues displaying talk user interface  602   a  without interruption if device  600  leaves the voice communication application only momentarily and returns to the talk user interface  602  prior to lapse of the momentarily window of time before device  600  tears down connection with the communication channel. In this way, users are permitted to quickly view notifications in their respective applications without necessarily ending the communication channel. 
     In the examples shown at  FIGS. 6GA to 6GF , initially, both devices  600 ,  699   a  are connected to a voice communication channel for sending and receiving voice communications with one another via their respective talk user interfaces  602 ,  602   a . In  FIG. 6GA , the incoming notification  664   a  is received at device  600  during an active voice communication where touch input  620   d  is detected at talk affordance  606  and voice data is sent from device  600  to external device  699   a , causing audio output  630   a  corresponding to the voice data and visual output indication  628   a  at contact affordance  604   a  at external device  699   a . In this case, incoming notification  664   a  is suppressed from output at  FIGS. 6GA to 6GB  for the duration of the active voice communication. At  FIG. 6GC , the active voice communication ends whereupon device  600  no longer detects the touch input  620   d , and displays the notification alert  666   a  at  FIG. 6GD  corresponding to the incoming notification  664   a . At  FIG. 6GE , in response to touch input  674  on dismiss affordance  672 , notification alert  666   a  is removed from display and device  600  resumes display of talk user interface  602  at  FIG. 6GF . Throughout  FIGS. 6GA to 6GF , external device  699   a  displays talk user interface  602   a  without interruption, since device  600  did not leave the voice communication application. It is noted that in some examples, displaying notification alerts causes the device to become unavailable for voice communications while the notification is displayed. 
     In the examples shown at  FIGS. 6HA to 6HH , initially, both devices  600 , 699   a  are connected to a voice communication channel for sending and receiving voice communications with one another via their respective talk user interfaces  602 ,  602   a . At  FIG. 6HA , incoming notification  664   a  is received first, followed by second incoming notification  664   c  at device  600 . Both incoming notifications  664   b , 644   c  are received during an active voice communication where touch input  620   e  is detected at talk affordance  606  and voice data is sent from device  600  to external device  699   a , causing, at external device  699   a , audio output  630   a  corresponding to the voice data and visual output indication  628   a  at contact affordance  604   a . At  FIGS. 6HA to 6HB , incoming notifications  664   a,c  are queued in their arrival order and suppressed from output for the duration of the active voice communication. At  FIG. 6HC , the active voice communication ends whereupon device  600  no longer detects the touch input  620   e . Subsequently at  FIGS. 6HD to 6HG , device  600  displays the queued notification alerts  666   a ,  666   c  in the order that their corresponding notifications arrived. As shown at  FIGS. 6HE and 6HG , touch inputs  674   a  and  674   c , respectively, on dismiss affordance  672  at each notification alert  666   a ,  666   c  removes display of the notification alert and talk user interface  602  is displayed again at  FIG. 6HH . In some cases, the notification alerts  666   a ,  666   c  are automatically cycled through display in their queued order without requiring inputs on each dismiss affordance  672 . Throughout  FIGS. 6HA to 6HH , external device  699   a  displays talk user interface  602   a  without interruption, since device  600  did not leave the voice communication application. 
     Turning now to  FIGS. 6IA to 6IC , in some examples, when either device  600  or  699   a  becomes unavailable during voice communication, the communication channel becomes unavailable at both devices  600  and  699   a  and a contact unavailable screen is displayed. For instance, at  FIG. 61B , while external device  699   a  is detecting touch input  620   f  at its talk affordance  606   a  and capturing voice input while sending the captured voice input as voice data to device  600 , external device  699   a  becomes unavailable and its display screen turns off. Device  600  detects that the communication channel has dropped and/or that external device  699   a  has become unavailable at the communication channel, and transitions from talk user interface  602  to contact unavailable screen  640 , which includes visual representation  642  of the external contact (e.g., in this case, Jane&#39;s image), text (e.g., “Jane is unavailable”), and add affordance  644 . 
     Merely by way of example, the contact unavailable screen  640  is evoked when device  600  detects that external device  699   a  has: entered a timeout period for a do-not-disturb mode, that device  699   a  is a wearable device (e.g., smart watch) that is not currently being worn, device  699   a  is in another phone or VoIP call, device  699   a  is powered off or in an airplane mode setting where device  699   a  is not connected to any networks, device  699   a  is do-not-disturb mode, a silent mode, or another type of mode that suppresses notifications from being output, including a theater mode and a sleep mode, and/or device  699   a  is connected to another communication channel 
     Turning now to  FIGS. 6JA to 6JK , an example of connecting to a new contact via add affordance  644  initiated at contact unavailable screen  640  is shown. In the present example, John&#39;s device  600  detects touch input  676  on add affordance  644  ( FIG. 6JA ) and in response displays contacts list  678 . At  FIG. 6JB , in some examples, contacts list  678  slides onto display from a bottom of display screen of the device  600 . In the present example, contacts list  678  is sectioned by sub-lists, including a most recent contacts sub-list (e.g., including Jane Appleseed at device  699   a  that was previously in communication) that precedes remaining phonebook contacts list indexed alphabetically. In some examples, contacts list  678  first shows a sub-list of other contacts associated with other external devices that are identified as being capable of receiving voice communications via voice communications application and/or are identified as being currently available (e.g., powered on, having network connectivity) prior to displaying remaining phonebook contacts. Still, in some examples, contacts list  678  is sorted by frequency of use based on frequency of use by the voice communications application or generally frequent contacts of phonebook contacts. At  FIG. 6JB , contacts list  678  further includes cancel affordance  680  that when selected removes display of the contacts list  678  (e.g., by sliding the contacts list  678  downwardly off the display screen) and resumes to a previous display (e.g., contact unavailable screen  640  at  FIG. 6JA ). 
     At  FIG. 6JC , device  600  detects touch input  682  (e.g., tap input) on a contact in the contact list  678  (e.g., contact named Aaron Smith) or otherwise selects a contact from the contact list. In response to touch input  682 , device  600  initiates connection with Aaron&#39;s external device  699   b  to establish a communication channel unique to devices  600  and  699   b . While the communication channel is building pending acceptance by Aaron&#39;s external device  699   b , device  600  displays contact pending screen  684  at  FIGS. 6JD to 6JE . In the present example, contact pending screen  864  includes the visual representation  642 , in this case corresponding to the external contact that is pending connection (e.g., an image or monogram representing Aaron), text indicating the connection is pending (e.g., “Waiting for Aaron”), an animation  688  such as an arc circling Aaron&#39;s visual representation  642  providing visual feedback that connection is actively pending, and the add affordance  644  for causing display of the contacts list  678  when selected. 
     As shown further at  FIGS. 6JD , Aaron&#39;s device  699   b  receives connection request from John&#39;s device  600  and transitions display (e.g., from a clock screen displaying a current time) to an invitation screen  690   b  that includes text indicating the contact request (e.g., “John Appleseed wants to talk to you over Talk App. Do you want to talk?”), and an accept affordance  692  and decline affordance  694  (also referred to herein as “not now” affordance  694 ). In the present example, Aaron&#39;s device  699   b  displays invitation screen  690   b  in accordance with a determination that the pending connection with John is a new connection for device  699   b , such as a new communication channel between devices  600  and  699   b . In some embodiments, device  699   b  displays an “always accept” affordance, in addition to or in lieu of, one or more of the affordances of  FIG. 6JD . In such embodiments, in response to detecting “always accept” affordance, device  699   b  launches the voice communication application, finishes building the communication channel, and/or adds the contact John Appleseed (e.g., adds account(s) and/or device(s) associated with John Appleseed) to a whitelist for automatically answering future incoming session initiation requests, as discussed in more detail below. 
     At  FIG. 6JE , device  699   b  detects selection of the accept affordance  692  via touch input  696 , which causes launching of the voice communication application and/or finishing building the communication channel. 
     By way of example, at  FIG. 6JF , devices  600  and  699   b  display respective connection pending screens  698  and  698   b , respectively, indicating that the communication channel between devices  600 ,  699   b  has been accepted at both ends and is building connection. In some examples, connection pending screens  698 ,  698   b  are not displayed at one or both devices when network connection is speedy. In the current example, John&#39;s device  600  transitions from contact pending screen  684  to connection pending screen  698  by maintaining display of Aaron&#39;s visual representation  642  and the animation  688 , while removing add affordance  644  and updating the text (e.g., updated with “Connecting to Aaron”). At Aaron&#39;s device  699   b , connection pending screen  698   b  shows visual representation  642  for John. 
       FIGS. 6JG to 6JK  illustrate an example animation occurring at both devices  600 ,  699   b  as they transition from connecting to displaying their respective talk user interfaces  602 ,  602   b . For example, at John&#39;s device  600 , visual representation  642  of Aaron initially enlarges in size at  FIG. 6JG  and then reduces in size while receding toward an edge of device  600  and defining an updated contact affordance  604  that previously represented the previous contact, Jane. Talk affordance  606  appears at  FIG. 6JK , centralized on the display and visual indication  608  is animated forming around the contact affordance  604  and talk affordance  600 . At  FIG. 6JK , Aaron&#39;s device  699   b  displays similar talk user interface  602   b  including talk affordance  606   b , contact affordance  604   b  with visual representation  642  representing John, and visual indication  608   b . At  FIG. 6JK , devices  600  and  699   b  are ready for voice communications. 
     Meanwhile, as a further example shown at  FIGS. 6JA to 6JG , Jane&#39;s device  699   a  receives indication that John&#39;s device  600  is unavailable anytime Jane&#39;s device  699   a  attempts to connect to John&#39;s device  600  while John&#39;s device  600  is connected to another communication channel. In the current illustrated example, Jane&#39;s device  699   a  detects activation input  648   a  at rotatable input mechanism  616   a  ( FIG. 6JB ), detects touch input  654  on voice communication application launch icon  652  ( FIG. 6JC ) from home screen  650   a , and displays do-not-disturb screen  656   a  including a visual representation  642  corresponding to the latest contact (e.g., John&#39;s image). At  FIG. 6JE , Jane&#39;s device  699   a  detects touch input  660   a  at switch  612  (off position) and toggles off the do-not-disturb mode that may have been established previously at Jane&#39;s device  699   a . At  FIG. 6JF , since John&#39;s device  600  is current unavailable, Jane&#39;s device  699   a  transitions from the do-not-disturb screen  656   a  to contact unavailable screen  640   a  indicating that John, the last contact, is unavailable. 
     The following  FIGS. 6KA to 6KN, 6LA to 6LD, 6MA to 6MC, 6NA to 6NF  illustrate various examples for handling invitations for communication channels and connecting to new contacts. For clarity, the top row of illustrations in  FIGS. 6KA to 6KN, 6LA to 6LD, 6MA to 6MC, 6NA to 6NF  corresponds to user interfaces displayed on John&#39;s device  600 , and the bottom row of illustrations corresponds to user interfaces displayed on Aaron&#39;s device  699   b , also referred to as external device  699   b.    
     As shown in  FIGS. 6KA to 6KN , in some examples, invitations to connect are received and/or accepted when either device  600 ,  699   b  is out-of-app (e.g., not currently in the voice communications application or “Talk App” as shown in the figures). For example, John&#39;s device  600  at  FIGS. 6KA to 6KD  first displays contact list  678  and detects selection of Aaron Smith from the contact list  678  in response to touch input  682 . John&#39;s device  600  transitions to contact pending screen  684  which in the present depiction includes the elements discussed previously, including visual representation  642  for Aaron. Meanwhile, Aaron&#39;s device  699   b  receives indication of the incoming connection from John&#39;s device  600  and displays a notification  6000   b  (and/or in some examples, displays the invitation) that indicates the application (e.g., “Talk App”) corresponding to the notification  6000   b . At  FIGS. 6KD to 6KE , Aaron dismisses the notification  6000   b  with touch input  6002  (e.g., swipe input). As shown at  FIG. 6KE , dismissing the notification  6000   b  is animated as being swept off of the display screen. 
     Meanwhile, at  FIG. 6KD , John&#39;s device  600  detects activation input  648  at rotatable input mechanism  616  while displaying the contact pending screen  684 , and in some cases exits the voice communications application and displays another screen (e.g., current time at  FIG. 6KE ) while waiting for Aaron to accept connection. In  FIGS. 6KF to 6KK , John may check whether Aaron&#39;s connection is still pending by, merely by way of example, activating the display screen again at  FIG. 6KF  to display the home screen  650  at  FIG. 6KG , detecting touch input  654  on the voice communication application launch icon  652  at  FIG. 6KH , and launching the application which causes display of the contact pending screen  684  at  FIG. 6KI , since Aaron has not yet accepted. At  FIG. 6KI , John may close the application again via activation input  648  and resume display of another screen (e.g., current time at  FIGS. 6KJ to 6KK ). In another example, John may choose to connect to another contact via add affordance  644  on contact pending screen  684 . 
     While John is waiting on Aaron&#39;s acceptance, Aaron at a later time (e.g., at  FIG. 6KF ) can see an unread message indicator  6004  on the display screen at device  699   b , such as a circle or dot on an upper portion of the display. The unread message indicator  6004  corresponds to the unread talk app notification  6000   b  that was previously dismissed. Aaron requests to view the notification  6000   b  at the later time via touch input  6002   a  (e.g., swipe input downward and/or opposite direction of  6002 ) which brings notification  6000   c  back into display (e.g., a banner view of notification  6000   b ). In response to detecting touch input  6000   c  on the notification  6000   c , invitation screen  690   b  appears and Aaron accepts the connection via touch input  696  on accept affordance  692  at  FIG. 6KK . 
     At  FIG. 6KK , Aaron accepts the invitation while John&#39;s device  600  is out-of-app. At  FIG. 6KL , Aaron&#39;s device  699   b  transitions from the invitation screen  690   b  to connection pending screen  698   b  has accepted connection of the communication channel between device  600  and  699   b  by nature of John&#39;s invitation request to Aaron. Since John&#39;s device  600  is out-of-app, John&#39;s device  600  receives indication that Aaron&#39;s device  699   b  and displays invitation status notification  6008 . At  FIG. 6KL , the invitation status notification  6008  includes text indicating the status of the invitation (e.g., “Aaron Smith accepted your invitation.”), launch affordance  670  (e.g., “Talk”) and dismiss affordance  672 . At  FIG. 6KM , touch input  674   d  (e.g., tap) on launch affordance  670  launches the voice communication application which displays the talk user interface  602  with contact affordance  604  having a visual representation of Aaron, while Aaron&#39;s device  699   b  displays talk user interface  60   b  with contact affordance  604   b  having a visual representation of John. At  FIG. 6KN , John and Aaron are connected at the communication channel and can communicate with one another by activation of the talk affordances  606 ,  606   b  on the respective talk user interfaces  602 ,  602   b.    
     Turning now to  FIGS. 6LA to 6LD , in another example, John dismisses the invitation status notification  6008  via touch input  674   e  on dismiss affordance  694  and returns to displaying another screen (e.g., current time at  FIGS. 6LB to 6LC ). Meanwhile, Aaron has accepted the invitation and is connected to the communication channel at  FIG. 6LA , and displays the talk user interface  602   b  associated with John. At  FIGS. 6LC to 6LD , Aaron activates talk affordance  606   b  with touch input  620  to talk to John, and John&#39;s device, in response, issues perceptual notification  626  followed by the audio output  630  corresponding to Aaron&#39;s speech and launching of the voice communication application that displays the talk user interface  602  corresponding to Aaron. 
     Turning now to  FIGS. 6MA to 6MC , in another example, John&#39;s device  600  is out-of-app when Aaron declines the invitation. For example, at  FIG. 6MB , Aaron&#39;s device  699   b  detects touch input  696  on the decline affordance  694 , which removes display of the invitation screen  690   b  at  FIG. 6MC  and causes device  699   b  not to connect to the communication channel. While John&#39;s device  600  is in-app and showing contact pending screen  684 , John&#39;s device  600  receives indication that the communication channel is not available, or otherwise that Aaron has not accepted the connection, and transitions to contact declined screen  6010  at  FIG. 6MC , which includes visual representation  642  of the contact (e.g., image of Aaron), text indicating the invitation is declined (e.g., “Aaron declined”), and add affordance  644  for choosing another contact for connection via contacts list. 
     Turning now to  FIGS. 6NA to 6NC , in some examples, invitations are declined while the sender is out-of-app. Merely by way of example, John&#39;s device  600  at  FIGS. 6NA to 6NE  first displays contact list  678  and detects selection of Aaron Smith from the contact list  678  in response to touch input  682 . John&#39;s device  600  transitions to contact pending screen  684 . John decides to not wait on the contact pending screen  684  by providing activation input  648  at rotatable input mechanism  616 , which removes display of the contact pending screen  684  at  FIG. 6NE . Meanwhile, Aaron&#39;s device  699   b  receives indication of the incoming connection from John&#39;s device  600  and displays a notification  6000   b  (and/or in some examples, displays the invitation) that indicates the application (e.g., “Talk App”) corresponding to the notification  6000   b.    
     Referring now to exemplary specifics of establishing voice communications from the perspective of Aaron&#39;s device  699   b , device  699   b  receives a request to establish a live audio communication session with an additional device (e.g., John&#39;s device  600 ). For example, the request is, in some cases, a signal transmitted according to Session Initiation Protocol (SIP) that includes an INVITE request and a description unit specifying the media format of the live audio communication session. In the example of  FIG. 6NB , the request is sent to Aaron&#39;s device  699   b  by John&#39;s device  600  in response to detecting selection of Aaron Smith from contact list  678  by touch input  682 . 
     In response to the session initiation request, device  699   b  in some cases, determines whether a contact associated with device  600  (e.g., John) is on a list. In some embodiments, the list is a whitelist that contains contacts with which device  699   b  has previously established a live audio communication session via the application (e.g., the “Talk App”). In another embodiment, the list is Aaron&#39;s contact list, similar to contact list  678  displayed on device  600 . 
     If device  699   b  finds the contact associated with requesting device  600  on the list, device  699   b  automatically accepts the session initiation request and proceeds to establish a live audio communication session with device  600  without first receiving a user input that acknowledges the request. Media channels and/or control channels are optionally allocated to the audio communication session, allowing device  600  to send control data and/or voice audio data to device  699   b . In this way, device  699   b  automatically answers a session initiation request (e.g., an incoming call) from a device associated with a whitelisted contact. 
     In some embodiments, in accordance with a determination that the contact is not on the list, however, device  699   b  establishes the live audio communication session (e.g., connect to the appropriate media and/or control channels) only in response to detecting a user input that acknowledges the session invitation. In particular, referring back to the examples of  FIGS. 6JD  and  6 J 5 , Aaron&#39;s device  699   b  receives a session initiation request from a device (e.g., device  600 ) associated with an un-vetted contact. If device  699   b  determines that the contact associated with the requesting device  600  is not on its whitelist, device  699   b  waits for a user input that accepts the request (e.g., user input  696  on accept affordance  692 ). Invitation screen  690   b  is displayed while waiting for the user input. In response to detecting a user input at the accept affordance, device  699   b  establishes the live audio communication session with requesting device  600  by sending one or more SIP response codes to device  600  and connecting to the one or more communication channels allocated to the live audio communication session. Optionally, device  699   b  adds the contact associated with requesting device  600  to the whitelist. Thus, future session invitations from device  600  will be automatically accepted as discussed above. 
     In some embodiments, device  699   b  disables audio input to its microphone (e.g., microphone  113 ) immediately after establishing the full-duplex live audio communication session. Alternatively and/or additionally, device  699   a  optionally mutes its uplink to media channel  1506 . In some cases, the transmitter, the analog-to-digital converter associated with the transmitter and/or the audio codec associated with the transmitter on device  699   a  are also powered down while the microphone is disabled. Audio input to the microphone (and/or the various transmitter components of device  699   b ) optionally remains disabled until enabled by the user (e.g., by activating talk affordance  606   a ). 
     Referring now to the specifics of sending voice communication requests from the perspective of  699   b , device  699   b  receives a user input (e.g., a touch gesture) corresponding to selection of a contact (e.g., from contact list  678 ) associated with an external device (e.g., device  600 ). In response to receiving the user input, device  699   b  optionally queries the network (e.g., network  1702 ) to determine if the contact supports communications using the voice communication application. Alternatively, the contact list (e.g., contact list  678 ) for the voice communication application is optionally populated only by contacts that support communication over the voice communication application. In response to the user input selecting an appropriate contact, device  699   a  sends a request to establish a live audio communication session to device  600 . For example, in some cases, the request is a signal transmitted according to Session Initiation Protocol (SIP) that includes an INVITE request and a description unit specifying the media format of the live audio communication session. After sending the session initiation request, device  699   b  optionally adds the contact associated with device  600  to its whitelist such that future requests from device  600  are automatically accepted in the manner discussed above. In the example of  FIGS. 6LA through 6LD , John&#39;s device  600  has whitelisted Aaron&#39;s device  699   b  by accepting a previous session request from device  699   b  (see  FIG. 6KK ). As a result, when Aaron activates talk affordance  606   b  (e.g., with touch input  620   g ), the session request sent to John&#39;s device is automatically accepted and John&#39;s device outputs incoming audio data and displays talk user interface  602 . 
     Referring back to user interface flow associated with session invitations and to  FIGS. 6ND to 6NF , notification  6000   b  was not dismissed and proceeds to displaying invitation screen  690   b . Aaron chooses the decline affordance  694  via touch input  696  and the invitation screen  690   b  is removed from display at  FIG. 6NF . At  FIG. 6NF , John&#39;s device  600  is out-of-app and receives indication that Aaron declined the connection. John&#39;s device  600  displays invitation status notification  6008  with launch affordance  670  to launch the voice communication application, connect to another contact, and dismiss affordance  672  to remove the notification  6008 . 
     Turning now to  FIGS. 6OA to 6OH , examples of when a contact is unavailable is shown. For clarity, the top row of illustrations in  FIGS. 6OA to 6OH  corresponds to user interfaces displayed on John&#39;s device  600 , the middle row of illustrations corresponds to user interfaces displayed on Jane&#39;s device  699   a , and the bottom row of illustrations corresponds to user interfaces displayed on Aaron&#39;s device  699   b.    
     Initially at  FIGS. 6OA to 6OB , John&#39;s device  600  and Jane&#39;s device  699   a  are in an active voice communications, where touch input  620   h  is detected at talk affordance  606   a  in Jane&#39;s talk user interface  602   a  and voice data is sent from Jane&#39;s device  699   a  to John&#39;s device  600 , causing, at John&#39;s device  600 , audio output  630  corresponding to the voice data. At  FIG. 6OB , John&#39;s device  600  detects touch input  660  at switch  612  to toggle off and enter do-not-disturb mode, as indicated with display of do-not-disturb screen  656  at  FIGS. 6OC to 6OG . Accordingly, Jane&#39;s device  699   a  detects that John&#39;s device  600  is no longer available and transitions from talk user interface  602   a  to contact unavailable screen  640   a  at  FIGS. 6OC to 6OG . At  FIG. 6OG , John&#39;s device  600  detects another touch input  660  at switch  612  to toggle on and exit do-not-disturb mode, and while Jane&#39;s device  699   a  is still in-app, both devices  600 ,  699   a  transition to display their respective talk user interfaces  602 ,  602   a  again at  FIG. 6OH . 
     Meanwhile at Aaron&#39;s device  699   b  in  FIGS. 6OA to 6OD , Aaron launches the voice communication application from home screen  650  at  FIG. 6OB  and displays contact unavailable screen  640   b , showing visual representation  642  of John who was the last connection at Aaron&#39;s device  699   b . In some examples, the contact unavailable screen  640   b  for John appears when the connection with John has timed out or was otherwise previously ended. At  FIG. 6OD , Aaron selects add affordance  644  via touch input  676  to cause display of contacts list  678 , which shows John in the “recents” sub-list since John was a recent contact. At  FIG. 6OF , Aaron selects John with touch input  682  and attempts to connect to John&#39;s device  600 . However, as shown at  FIGS. 6OG to 6OH , Aaron&#39;s device  699   a  receives indication that John&#39;s device  600  is unavailable and displays contact unavailable screen  640   b . In this case, John&#39;s device  600  is unavailable to Aaron&#39;s device  699   b  since John&#39;s device  600  is already in communication with Jane&#39;s device  699   a.    
     It is noted that some examples, contact unavailable screen  640 ,  640   a , or  640   b  is displayed after a connection at a communication channel has timed out, and/or otherwise ended by closing the voice communication application. For example, subsequent to  FIG. 6OI , both John and Jane&#39;s devices  600 ,  699   a  can transition to contact unavailable screens  640 ,  640   a  indicating John and Jane are unavailable to each other. At the same time however, John&#39;s device  600  may appear available to Aaron&#39;s device  699   a . Similarly, John and/or Jane may re-establish connection by choosing the other from their respective contacts lists. 
     The following figures starting with the set of  FIGS. 7AA to 7AI  through ending with the set of  FIGS. 7EA to 7ED  illustrate exemplary user interfaces for electronic communications, and transitions between the user interfaces, in accordance with some embodiments. The user interfaces in these figures are used to illustrate the processes described below, including the processes shown at  FIG. 10 . It is noted that the flow of the user interfaces presented herein are only some examples of a variety of possible flows available in the voice communications techniques disclosed herein, and that in some cases, the flow of user interfaces can be modified and/or rearranged without departing from the spirit of the invention. 
       FIGS. 7AA to 7AI and 7BA to 7BH  depict exemplary user interfaces and transitions thereof for voice communications, and particularly examples for switching communication channels, between the users of computing devices  600 ,  699   a , and  699   b . For clarity, the top row of illustrations corresponds to user interfaces displayed on John&#39;s device  600 , the middle row of illustrations corresponds to user interfaces displayed on Jane&#39;s device  699   a , and the bottom row of illustrations corresponds to user interfaces displayed on Aaron&#39;s device  699   b . Further, a fourth row of illustrations at  FIGS. 7CA to 7CH, 7DA to 7DD, and 7EA to 7ED  corresponds to user interfaces displayed on Emily&#39;s device  699   c , which is also a computing device  100 ,  300 , or  500  ( FIGS. 1A-1B, 3, and 5A-5B ). 
       FIGS. 7AA to 7AI  show examples for switching voice communications between contacts via a channel switch mode provided at the talk user interface. For example, at John&#39;s device  600 , while talk user interface  602  is in channel-switch mode, the talk user interface  602  is updated to channel switch mode user interface  700  (also referred to as channel switch mode  700 ) while maintaining connection to a currently connected voice communications channel. Initially at  FIG. 7AA , John&#39;s device  600  and Jane&#39;s device  699   a  are in the voice communication application and currently connected to one another through the communication channel, as indicated at their respective talk user interfaces  602 ,  602   a , respectively. Specifically, John&#39;s talk user interface  602  includes a first contact affordance  704   a  (hereinafter referred to as Jane&#39;s contact affordance  704   a ) while Jane&#39;s talk user interface  602   a  includes John&#39;s contact affordance  604   a.    
     To enter channel-switch mode at John&#39;s device  600 , touch input  702   a  on Jane&#39;s contact affordance  704   a  is detected and transitions display from talk user interface  602  at  FIG. 7AA  to channel switch mode  700  at  FIG. 7AC . Merely by way of example, an animated transition to (and subsequently, from) channel switch mode  700  is demonstrated at an intermediate stage at  FIG. 7AB , where talk user interface  602   x  is transitioning into channel switch mode  700  and visual indication  608   x  begins to separate into a first indicator  608   y  and second indicator  608   z  of  FIG. 7AC . At  FIG. 7AC , channel switch mode  700  is shown, and includes Jane&#39;s contact affordance  704   a  at a first position with first indicator  608   y  and an add affordance  644  at a second position. Second indicator  608   z  is displayed at talk affordance  606 . The first and second indicators  608   y ,  608   z  provide visual feedback that John&#39;s device  600  is still connected to the communication channel with Jane&#39;s device  699   a  even though the display has changed. Accordingly, Jane&#39;s device  699   a  at  FIGS. 7AA to 7AC  continues to display talk user interface  602   a  as the communication channel is not interrupted by entering channel switch mode  700 . For example, voice communications can still be relayed between devices  600  and  699   a , as demonstrated at  FIG. 7AD . At  FIG. 7AD , Jane&#39;s device  699   a  shows talk affordance  606   a  being activated by touch input  620   i , which captures voice input at device  699   a  and sends voice data corresponding to the captured voice input to John&#39;s device  600 . John&#39;s device  600  continues to issue audio output  630  and provide visual output indication  628  at Jane&#39;s contact affordance  704   a  even though the talk user interface  602  has transitioned into the channel switch mode  700 . Similarly, John can activate talk affordance  606  from the channel switch mode  700  at  FIG. 7AD  to send voice data back to Jane&#39;s device  699   a.    
     At  FIG. 7AD , while John&#39;s device  600  is in channel switch mode  700 , touch input  702   j  is detected at the add affordance and causes display of the contacts list  678  at  FIG. 7AE . At  FIG. 7AF , touch input  682  selects a contact (e.g., Aaron Smith) from the contacts list  678  and attempts to connect to the external device associated with the contact (e.g., Aaron&#39;s device  699   b ). While waiting for Aaron&#39;s device to connect, John&#39;s device displays contact pending screen for Aaron and ceases to display the talk user interface  602 , because the communication channel with Jane&#39;s device  699   a  has become unavailable since John&#39;s device  600  can only connect to a single communication channel at the voice communications application at a time. Accordingly, Jane&#39;s device  699   a  transitions from talk user interface  602   a  to contact unavailable screen  640   a  at  FIGS. 7AG to 7AI . 
     At  FIGS. 7AG to 7AH , Aaron&#39;s device  699   b  receives the connection request to connected to a communication channel with John&#39;s device  600  and displays invitation screen  690   b  including the accept affordance  692  and decline affordance  694 . In response to detecting selection of accept affordance  692  via touch input  696  at  FIG. 7AH , Aaron&#39;s device  699   b  transitions the display into talk user interface  602   b  at  FIG. 7AI  showing contact affordance  604   b  (representing John). John&#39;s device  600  receives an indication that the communication channel between devices  600 ,  699   b  has been established and/or otherwise that Aaron has approved connection. At  FIG. 7AI , John&#39;s device  600  displays talk user interface  602  with an updated contact affordance showing Aaron&#39;s contact affordance  704   b . Aaron&#39;s contact affordance  704   b  is associated with talk affordance  606  via the visual indicator  608 . 
     Turning now to  FIGS. 7BA to 7BH , an example channel switch mode  700  is shown where device  600  has previously connected to another contact&#39;s device (e.g., Jane&#39;s device  699   a ). The channel switch mode  700  allows users to quickly switch between communication channels of recent contacts by displaying the contact affordance of a most-recent and/or a most-frequent contact to allow for quick selection and connection to that contact. 
     For example, at  FIG. 7BA , while John&#39;s device  600  displays talk user interface  602  with Aaron&#39;s contact affordance  704   b , touch input  702   b  on Aaron&#39;s contact affordance  704   b  initiates transition (at  FIG. 7BB ) into channel switch mode  700  at  FIG. 7BC . At  FIG. 7BC , channel switch mode  700  maintains display of Aaron&#39;s contact affordance  704   b  and causes further display of Jane&#39;s contact affordance  704   a  since Jane was the last contacted contact. Specifically, Jane&#39;s contact affordance  704   a  is displayed at the second position (e.g., the second position where add affordance  644  was located in  FIGS. 7AC to 7AD ) adjacent to Aaron&#39;s contact affordance  704   b  at the first position, and add affordance  644  is bumped to the far right at a third position. In the channel switch mode  700 , indicator  608   y  at Aaron&#39;s contact affordance  704   b  indicates that the communication channel between John&#39;s device  600  and Aaron&#39;s device  699   a  is still connected. As such, Aaron&#39;s device  699   b  from  FIGS. 7BA to 7BD  continues to display the talk user interface  602   b  associated with John, while Jane&#39;s device  699   a  continues to display contact unavailable screen  640   a  indicating John is unavailable. 
     At  FIGS. 7BD to 7BE , upon detecting selection of Jane&#39;s contact affordance  704   a  from touch input  702   c , John&#39;s device  600  disconnects from the communication channel associated with Aaron&#39;s device  699   b  and connects to the communication channel associated with Jane&#39;s device  699   a . As such, Jane&#39;s device  699   a  transitions from displaying contact unavailable screen  640   a  to talk user interface  602   a  associated with John, while Aaron&#39;s device  699   b  transitions from displaying talk user interface  602   b  associated with John to displaying contact unavailable screen  640   b.    
     As further shown at  FIG. 7BE , at John&#39;s device  600 , indicator  608   y  has jumped to the selected contact&#39;s affordance, Jane&#39;s contact affordance  704   a , to indicate that talk affordance  606  is now associated with Jane&#39;s device  699   a .  FIGS. 7BF to 7BH  show an example animated transition from channel switch mode  700  to talk user interface  602 , where the previous contact affordance, Aaron&#39;s contact affordance  704   b , slides off of display as it is being pushed off from the first position by Jane&#39;s contact affordance  704   a , and add affordance  644  collapses or otherwise shrinks and disappears.  FIG. 7BG  shows another intermediate stage of the animation at talk user interface  602   x , where indicators  608   y  and  608   z  are in the process of merging into a single border  608   x  associating Jane&#39;s contact affordance  704   a  with talk affordance  606 . 
     Turning now to  FIGS. 7CA to 7CH , a further example of channel switch mode  700  is shown. While John&#39;s device  600  and Jane&#39;s device  699   a  are connected at their communication channel, at  FIG. 7CA , in response to touch input  702   d  detected at Jane&#39;s contact affordance  704   a , device enters channel switch mode  700  at  FIG. 7CB . As shown in channel switch mode  700 , Jane&#39;s contact affordance  704   a  is maintained at the first position with indicator  608   y  indicating that the current communication channel is associated with Jane&#39;s device  699   a . Aaron&#39;s contact affordance  704   b  is shown at the second position, indicating Aaron&#39;s device is a most recent and/or most frequent contact of any remaining other contacts. At  FIG. 7CC , John&#39;s device  600  detects touch input  702   e  on add affordance and displays contacts list  678  at  FIG. 7CD , which shows Jane Appleseed and Aaron Smith under a “recents” sub-list. At  FIG. 7CE , contacts list  678  has been scrolled down to find another contact, Emily Miles, and subsequently receive touch input  678  selecting Emily Miles. In response to detecting the selection, John&#39;s device  600  at  FIGS. 7CF to 7CH  displays contact pending screen  684  showing a visual representation for Emily before transitioning to talk user interface  602  at  FIG. 7CH , which shows Emily&#39;s contact affordance  704   c , after Emily&#39;s device  699   c  has accepted the connection via touch input  696  on accept affordance  692  of invitation screen  690   c  at  FIG. 7CG . 
     In the present example, in response to detecting the selection via touch input  678  for Emily from the contacts list  678 , device  600  disconnects from the communication channel with Jane&#39;s device  699   a  in order to establish connection or otherwise attempt to connect to another communication channel with Emily&#39;s device  699   c . As shown, Jane&#39;s device  699   a  transitions to contact unavailable screen  640   a  at  FIGS. 7CE to 7CH  upon receiving indication that the communication channel with John&#39;s device  600  is no longer available. 
     Turning now to  FIGS. 7DA to 7DD , in some examples during channel switch mode  700 , no channels are switched. For example, as shown at  FIG. 7DA to 7DB , John&#39;s device  600  is connected to the communication channel with Emily&#39;s device  699   c . In response detecting touch input  704   f  on Emily&#39;s contact affordance  704   c  at talk user interface  602 , device  600  enters channel switch mode  700  at  FIG. 7DB , which maintains Emily&#39;s contact affordance  704   c  at the first position, causes display of Jane&#39;s contact affordance  704   a  at the second position indicating Jane was the most recent or most frequent contact, and add affordance  644 . As shown at  FIG. 7DC , in response to detecting another touch input  704   g  at Emily&#39;s contact affordance  704   c  during channel switch mode  700 , device  600  maintains the communication channel that is currently connected and transitions back to talk user interface  602  associated with Emily&#39;s contact affordance  704   c . As shown at Emily&#39;s device  699   c , the talk user interface  602   c  associated with John&#39;s device  600  continues to be displayed through  FIGS. 7DA to 7DD  since the communication channel was not disconnected. 
     Turning now to  FIGS. 7EA to 7ED , in some examples during channel switch mode  700 , no communication channels are connected and the device enters an idle state at the voice communication application. For example, as shown at  FIG. 7EA to 7EB , John&#39;s device  600  is connected to the communication channel with Emily&#39;s device  699   c . In response detecting touch input  704   h  on Emily&#39;s contact affordance  704   c  at talk user interface  602 , device  600  enters channel switch mode  700  at  FIG. 7EB , which maintains Emily&#39;s contact affordance  704   c  at the first position, causes display of Jane&#39;s contact affordance  704   a  at the second position indicating Jane was the most recent or most frequent contact, and add affordance  644 . As shown at  FIG. 7EC to 7ED , in response to detecting a touch input  704   i  at Jane&#39;s contact affordance  704   a  during channel switch mode  700 , device  600  disconnects from the communication channel with Emily&#39;s device  699   c  and attempts to connect to the communication channel that is associated with Jane&#39;s device  704   a . In this example, Jane&#39;s device  699   a  may be powered off, lacking network connectivity, and/or otherwise unavailable. At  FIG. 7ED , John&#39;s device  600  receives indication of the status of Jane&#39;s device  600   a  and displays contact unavailable screen  640  indicating that Jane is unavailable. At this state, John&#39;s device  600  is disconnected from Emily&#39;s device  699   c  and did not connect to Jane&#39;s device  699   a  and is therefore in an idle state where no communication channel is currently connected. Optionally, John can select add affordance  644  at contact unavailable screen  640  to connect to another communication channel. 
     The following figures  FIGS. 8A-8X  illustrate exemplary user interfaces for electronic communications, and transitions between the user interfaces, in accordance with some embodiments. The user interfaces in these figures are used to illustrate the processes described below, including the processes shown at  FIG. 11 . It is noted that the flow of the user interfaces presented herein are only some examples of a variety of possible flows available in the voice communications techniques disclosed herein, and that in some cases, the flow of user interfaces can be modified and/or rearranged without departing from the spirit of the invention. 
       FIGS. 8A-8X  depict exemplary user interfaces and transitions thereof for voice communications between the users of computing devices  600  and  699   a  in an example first time user setup or onboarding experience at the voice communications application at device  600 . For clarity, the top row of illustrations corresponds to user interfaces displayed on John&#39;s device  600 , and the bottom row of illustrations corresponds to user interfaces displayed on Jane&#39;s device  699   a.    
     As shown at  FIG. 8A , device  600  receives activation input  648  on rotatable input mechanism  616  and displays, at  FIG. 8B , home screen  650  including voice communications application launch icon  652 . In response to detecting touch input  654  selecting the launch icon  652 , and in accordance with a determination no relationships have been previously established at the device  600 , voice communications application displays a welcome screen  800  that includes a representative symbol or glyph  802  of the application, brief text describing the application (e.g., “A fun way to talk to other Watch users”), name of the application (e.g., “Talk App”), and a get started affordance  804  for continuing with onboarding. 
     In response to detecting touch input  806   a  at the get started affordance  804  at  FIG. 8D , device  600  transitions to displaying an add screen  808  including initial add affordance  810  and brief instructions (e.g., “Add a person to begin”). At  FIG. 8F , in response to detecting touch input  806   b  on the displayed initial add affordance  810 , device  600  displays contact list  678 . At  FIG. 8H , in response to detecting selection of a contact, for example detecting touch input  682  on Jane Appleseed from contacts list  678 , device  600  attempts to connect to Jane&#39;s device  699   a , which receives indication of the attempt and issues a perceptual notification  812 . In some examples, perceptual notification  812  is similar to the haptic and/or audible output as perceptual notification  626  described in the foregoing paragraphs. 
     As shown at  FIGS. 8I-8J , after initiating connection with Jane&#39;s device  699   a  from contacts list  678 , device John&#39;s device  600  displays contact pending screen  684  while waiting for Jane&#39;s device  699   a  to accept or decline connection. Jane&#39;s device  699   a  displays invitation screen  690   a  including the accept affordance  692  and not now affordance  694 , and detects touch input  696  on accept affordance  692  at  FIG. 8J  to accept connection to the communication channel with John&#39;s device  600 . 
     As shown throughout  FIGS. 8K-8P , voice inputs are captured at their respective devices  600 ,  699   a  in response to activation of talk affordances  606   a  and  606  with touch inputs  620   j  ( FIGS. 8L-8M ) and  620   k  ( FIGS. 8O-8P ), and transmitted as voice data between Jane&#39;s device  699   a  and John&#39;s device  600  at the communication channel. At  FIG. 8Q , activation input  648  at rotatable input mechanism  616  at John&#39;s device  600 , and/or activation input  648  at rotatable input mechanism  616   a  at Jane&#39;s device  699   a , closes the voice communication application and disconnects the communication channel. Merely by way of example, if John&#39;s activation input  648  initiates disconnection before Jane&#39;s activation input  648   a , then Jane&#39;s device  699   a  receives indication that John has closed or otherwise exited the voice communications application at John&#39;s device  600 , and that the communication channel is no longer available. In response, Jane&#39;s device  699   a  automatically closes the voice communications application and displays another screen at device  699   a  (e.g., current time at  FIG. 8K ). However, if Jane&#39;s activation input  648   a  is first to disconnect the communication channel, then John&#39;s device  600  detects that the communication channel is no longer available, and automatically closes or exits the voice communications application and displays another screen at device  600  (e.g., current time at  FIG. 8K ). 
     As shown further throughout  FIGS. 8S-8X , in some examples, John&#39;s device  600  re-enters voice communication application upon detecting subsequent selection  654  of voice communications application launch icon  652  from home screen  650  ( FIG. 8U ). In some examples at  FIGS. 8V-8X , communications via the communication channel are resumed upon detecting touch input  620   l  on talk affordance  606  at John&#39;s device  600 . 
       FIG. 9  is a flow diagram illustrating a method  900  for electronic voice communications using an electronic device in accordance with some embodiments. Method  900  is performed at a device (e.g.,  100 ,  300 ,  500 ) with a display with a touch-sensitive surface, such as a touch-sensitive display, and in some examples further with a microphone and speakers. Some operations in method  900  are, optionally, combined, the order of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  900  provides an intuitive way for electronic voice communications. The method reduces the cognitive burden on a user for voice communications, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to communicate faster and more efficiently conserves power and increases the time between battery charges. 
     At block  902 , the electronic device receives a data signal, including voice data, from an external device (e.g., device  699   a ) associated with a contact. For example, the data signal can optionally include a start message and audio data. 
     In accordance with some embodiments, the electronic device, in response to receiving the data signal, activates the display screen and launches an application associated with the voice data (e.g.,  FIGS. 6CB to 6CC ). For example, the device launches the application and displays the talk user interface  602 . 
     At block  904 , in response to receiving the data signal, the electronic device issues a perceptual notification (e.g., perceptual notification  626 ) distinct from the voice data. For example, the device can optionally issue a haptic output and audible ding in response to receiving the start message. Issuing the perceptual notification in response to receiving the data signal provides the user with feedback that an incoming communication has arrived at the device and provides further feedback to the user indicating that voice data is about to be automatically and audibly output. In some examples, the perceptual notification permits the user to stop automatic audio output of the voice data in situations where it is inconvenient for audio output. Providing improved feedback enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, the electronic device determines whether a user input (e.g., quiet gesture  638 ) is detected during the predetermined delay period (e.g., 250 ms, 500 ms, or 1000 ms). 
     In accordance with some embodiments, the perceptual notification (e.g., perceptual notification  626 ) includes a haptic output or an audible output. For example, the perceptual notification can include both haptic output and audible output. 
     At block  906 , subsequent to issuing the perceptual notification and in accordance with a determination that a user input is not detected on the display within a predetermined delay period (e.g., 250 ms, 500 ms, or 1000 ms), the electronic device causes audio output (e.g., audio output  630 ) of the voice data. For example, the user input is a palm-to-watch gesture that, when not received, causes automatic output of voice data at the speaker or through headphones. Automatically causing audio output of the received voice data when the user input is not detected allows the user to quickly and efficiently communicate with the contact without needing to provide further input (e.g., to answer the contact&#39;s incoming message before playing) and enables the user to multitask while still hearing the live voice data when it arrives and without delay. Performing an operation when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, at block  908 , in response to detecting the user input (e.g., quiet gesture  638 ) during the predetermined delay period (e.g., 250 ms, 500 ms, or 1000 ms), the electronic device enters a timeout period for a predetermined duration of time (e.g., 5 minutes, 7 minutes, or 10 minutes) and automatically exits the timeout period upon expiration of the predetermined duration of time. In some examples, the electronic device receives a second data signal including second voice data. In some examples, the electronic device, in accordance with a determination that the second data signal is received during the timeout period, forego issuance of a second perceptual notification corresponding to the second data signal and respond to a source of the second data signal with an unavailable status (e.g., contact unavailable screen  640 ). In some examples, the electronic device, in accordance with a determination that the second data signal is not received during the timeout period (e.g., 5 minutes, 7 minutes, or 10 minutes), issues the second perceptual notification (e.g., perceptual notification  626 ) distinct from the second voice data. Automatically entering a timeout period in response to detecting the user input allows the user to quickly silence the device and prevent audio output of voice data under inconvenient circumstances (e.g., user is in a meeting) and enables the user to stay in the do-not-disturb mode for a period of time without requiring further inputs to enter a do-not-disturb mode. Automatically exiting the timeout period further allows the user to continue to receive incoming voice data, for example at a later time, and prevents accidentally missing incoming voice data if the user forgets to exit the timeout period. Performing an operation when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, the electronic device, in response to receiving a user request (e.g., touch input  660  at switch  612 ) to exit the timeout period during the timeout period, exits the timeout period (e.g.,  FIG. 6DE ). For example, prior to lapse of the timeout period (e.g., 5 minutes, 7 minutes, or 10 minutes), the device detects touch input  660  to manually toggle switch  612  to an on position, which exits the timeout period and transitions from do not disturb screen  656  to talk user interface  602  with a most-recent contact. 
     In accordance with some embodiments, the electronic device, while causing audio output, displays a talk user interface (e.g., talk user interface  602 ) including a talk affordance (e.g., talk affordance  606 ) for communicating data with the external device (e.g., external device  699   a ), wherein the external device is a first external device associated with a first contact, and a contact affordance (e.g., contact affordance  604 ), wherein the contact affordance is a first affordance representing the first contact. For example, the communicated data includes voice data corresponding to voice input captured at the microphone. In another example, the monogram or image represents the first contact at the contact affordance  604 . 
     In accordance with some embodiments, the electronic device, while causing audio output (e.g., audio output  630 ), displays, in the talk user interface (e.g., talk user interface  602 ), an output indication (e.g., visual output indication  628 ). For example, output indication is animation of ripples emerging from the contact affordance  604  that is displayed for a duration of the audio output  630  and removed after the audio output  630  ceases. In some examples, the device issues an end-of-message perceptual notification for a haptic output and audible output to indicate an end of the audio output  630 . 
     In accordance with some embodiments, the electronic device displays in the talk user interface (e.g., talk user interface  602 ) a visual indication (e.g., visual indication  608 ) that communications via the talk user interface are associated with the first contact. For example, the visual indication is merged white circles at the talk affordance  606  and contact affordance  604 . 
     In accordance with some embodiments, the electronic device, while causing audio output (e.g., audio output  630   a ), adjusts a volume level of the audio output in accordance with a detected rotational input (e.g., rotational input  632 ) at a rotatable input mechanism (e.g., rotatable input mechanism  616   a ) at the device. For example, the device displays an indication of the adjusted volume level on the talk user interface  606  by animating the volume icon  610  on the talk user interface  602  in accordance with the rotation. 
     In accordance with some embodiments, the electronic device, in response to detecting activation of the talk affordance (e.g., talk affordance  606 ), captures voice input at the microphone, and while capturing voice input, sends an outgoing data signal including outgoing voice data corresponding to the captured voice input to the first external device (e.g., external device  699   a ). For example, the device captures voice input while a press-and-hold gesture at talk affordance  606  is detected, and/or while a single tap to start and subsequent tap to stop activation is detected. Further, for example, the device sends live voice data to the first external device. 
     In accordance with some embodiments, the electronic device, in response to detecting activation of the (e.g., talk affordance  606 ), issues a perceptual output (e.g., perceptual output  622 ) including a haptic output or an audible output, and while capturing voice input, displays, in the talk user interface (e.g., talk user interface  602 ), an input indication (e.g., visual input indication  624 ). For example, the device issues a perceptual output prior to capturing voice input. Further, for example, the device displays an animation associated with the talk affordance  606  for a duration of the activation, such as ripples emerging from talk affordance  606 . 
     In accordance with some embodiments, the electronic device receives a communication (e.g., incoming notification  664   a ) from a second external device. Further, the device can optionally, in response to receiving the communication and in accordance with a set of first time notification criteria being satisfied, including a criterion that is satisfied when the talk user interface (e.g., talk user interface  602 ) is not displayed, issue a third perceptual notification at a first time, and in response to receiving the communication and in accordance with the set of first time notification criteria not being satisfied, forgo issuing the third perceptual notification at the first time (e.g.,  FIGS. 6GA ). For example, the device delays issuing the perceptual notification to a second time later than the first time or not issuing the perceptual notification, and in some embodiments, logs the incoming communication for later retrieval from a notification center. 
     In accordance with some embodiments, the electronic device, while displaying the talk user interface (e.g., talk user interface  602 ), receives an indication that the first contact is unavailable, and in response to detecting that the first contact becomes unavailable, ceases display of the talk user interface (e.g.,  FIGS. 61B to 6IC ). For example, the device receives an indication that the communication channel is disconnected and subsequently closes the voice communications application, or replaces display of the talk user interface  602  with display of a contact unavailable screen  640 . 
     In accordance with some embodiments, while the talk user interface (e.g., talk user interface  602   b ) is not being displayed, the electronic device receives third data signal from a third external device associated with a third contact. In some examples, the electronic device, in response to receiving the third data signal and in accordance with a determination that the third contact satisfies an acceptance requirement criteria, including a criterion that is satisfied when the third contact has not been previously accepted for communication via the talk user interface, displays an invitation screen (e.g., invitation screen  690   b ) including an accept affordance (e.g., accept affordance  692 ) and a reject affordance (e.g., not now affordance  694 ). In some examples, the electronic device, in response to receiving selection (touch input  696 ) of the accept affordance (e.g., accept affordance  692 ), replaces display of the invitation screen (e.g., invitation screen  690   b ) with display of the talk user interface (e.g., talk user interface  602   b ) and updates the contact affordance (e.g., contact affordance  604 ) with a third contact affordance representing the third contact. In some examples, the electronic device, in response to receiving user selection of the reject affordance (e.g., not now affordance  694 ), ceases display of the invitation screen (e.g., invitation screen  690   b ). Further, for example, the device does not display talk user interface  606  when the device is in an idle state and/or is not connected to any communication channels. 
     At block  910 , subsequent to issuing the perceptual notification (e.g., perceptual notification  626 ) and in accordance with a determination that the user input (e.g., quiet gesture  638 ) is detected on the display within the predetermined delay period (e.g., 250 ms, 500 ms, or 1000 ms), the electronic device forgoes causing audio output of the voice data (e.g.,  FIG. 6BD ). For example, the palm-to-watch gesture detected before audio data is audibly output stops the audio data from being output and silences the device. Forgoing causing audio output of voice data after issuing the perceptual notification and in accordance with the determination that the user input is received within the delay period (e.g., 250 ms, 500 ms, or 1000 ms) allows the user to stop unwanted output of the voice communication in situations where audio output is undesirable and enables the user to do so quickly and easily without requiring numerous inputs. Reducing the number of inputs needed to perform an operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, the user input (e.g., quiet gesture  638 ) comprises a palm gesture covering a majority of the display. 
     In accordance with some embodiments, the electronic device, in response to detecting the user input (e.g., quiet gesture  638 ) while the display screen is on, turn the display screen off (e.g.,  FIG. 6CE ). 
     In accordance with some embodiments, at block  912 , the electronic device determines whether a second input (e.g., quiet gesture  638 ) is detected during audio output (e.g., audio output  630 ) of the voice data, and in accordance with a determination that the second user input (e.g., quiet gesture  638 ) is detected on the touch-sensitive display during audio output of the voice data, ceases audio output of the voice data (e.g.,  FIG. 6CE ). For example, the electronic device interrupts audio output  630  and stops receiving further voice data from electronic device  699   a . Ceasing audio output of voice data after the audio output has already started if a second user input is detected provides the user with more control of the device by helping the user avoid unintentionally executing audio output (e.g., when the user unintentionally misses the predetermined delay period to enter the first user input) and allows the user to hear at least a portion of the voice data prior to deciding whether to continue with audio output. Providing additional control options enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     Note that details of the processes described above with respect to method  900  (e.g.,  FIG. 9 ) are also applicable in an analogous manner to the methods described below. For example, methods  1000  and  1100  optionally include one or more of the characteristics of the various methods described above with reference to method  900 . For example, methods  1000  and  11000  can be combined with method  900  to further include that subsequent to issuing the perceptual notification and in accordance with a determination that the user input is detected on the display within the predetermined delay period (e.g., 250 ms, 500 ms, or 1000 ms), the device forgoes causing audio output of the voice data. For brevity, these details are not repeated below. 
       FIG. 10  is a flow diagram illustrating a method for electronic voice communications using an electronic device in accordance with some embodiments. Method  1000  is performed at a device (e.g.,  100 ,  300 ,  500 ) with a display with a touch-sensitive surface, such as a touch-sensitive display, and in some examples further with a microphone and speakers. Some operations in method  1000  are, optionally, combined, the order of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  1000  provides an intuitive way for electronic voice communications. The method reduces the cognitive burden on a user for communicating with others, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to communicate faster and more efficiently conserves power and increases the time between battery charges. 
     At block  1002 , while the electronic device is connected to (e.g., active, open line) a first communication channel associated with a first external device (e.g., device  699   b ) of a first contact and not connected (e.g., inactive, closed line) to a second communication channel associated with a second external device (e.g., device  699   a ) of a second contact, the electronic device concurrently displays a first affordance (e.g., contact affordance  704   b ) associated with the first contact and a second affordance (e.g., contact affordance  704   a ) associated with the second contact. For example, each of the first and second affordances is an image or monogram. Displaying both the first and second contact affordances while the device is currently connected to only one of the two contacts provides the user with feedback that another contact can be connected for voice communications and provides visual feedback to the user indicating a suggested other contact, for example a most-recent and/or most-frequent contact. Providing improved feedback enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, at block  1004 , the second contact (e.g., contact affordance  704   a ) is a most-recent contact that is determined based on meeting a set of most-recent contact criteria, including a criterion that is met when the second communication channel corresponding to the second contact is a most-recently-connected channel that was connected prior to connecting to a currently connected channel, wherein the currently connected channel is the first communication channel. Providing a most recent contact as the second contact allows the user to quickly switch between different voice communication channels, such as a between a currently connected channel and a previously connected channel, which may be more relevant to the user at the time than another communication channel that was not recently connected. Providing improved feedback enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, the electronic device concurrently displays the first affordance (e.g., contact affordance  704   b ) and the second affordance (e.g., contact affordance  704   a ) in response to receiving a first user request (e.g., touch input  702   b ) to enter a channel-switch mode (e.g., channel switch mode  700 ), wherein the first affordance (e.g., contact affordance  704   b ) is displayed at a first position on the display and the second affordance (e.g., contact affordance  704   a ) is displayed at a second position relative to the first position on the display. For example, the user request is tap input (e.g., touch input  702   b ) on the first affordance (e.g., contact affordance  704   b ) that causes display of the second affordance (e.g., contact affordance  704   a ). 
     In accordance with some embodiments, the second contact (e.g., contact affordance  704   a ) is a most-frequent contact that is determined based on meeting a set of most-frequent contact criteria, including a criterion that is met when the second communication channel corresponding to the second contact is ranked a most-frequently-connected communication channel of a plurality of previously-connected communication channels at the device. 
     In accordance with some embodiments, the second contact (e.g., contact affordance  704   a ) is a currently-available contact that is determined based on meeting a set of availability criteria, including a criterion that is met when the device receives an indication that the second communication channel corresponding to the second contact is available for connecting to the device. For example, the second contact (e.g., contact affordance  704   a ) is in network and/or has an electronic device that supports voice communications disclosed herein, such as any of devices  100 ,  300 , and/or  500 , and/or has the voice communications application on the electronic device. 
     In accordance with some embodiments, the electronic device while concurrently displaying the first affordance (e.g., contact affordance  704   b ) and the second affordance (e.g., contact affordance  704   a ) and while the device is connected to the first communication channel and not connected to the second communication channel, displaying a first talk affordance (e.g., talk affordance  606 ) for communicating with the first contact (e.g., contact affordance  704   b ) through the first communication channel. 
     In accordance with some embodiments, while the device is connected to the first communication channel and not connected to the second communication channel, the electronic device displays a first visual indication (e.g., indicators  608   y ,  608   z ) that the device is connected to the first communication channel, wherein the first visual indication (e.g., indicators  608   y ,  608   z ) is distinct from the visual indication (e.g., visual indication  608 ). For example, the first visual indication is two separate borders at the first affordance (e.g., contact affordance  704   b ) and the talk affordance (e.g., talk affordance  606 ). 
     In accordance with some embodiments, subsequent to receiving a first data signal including first voice data at the first communication channel from the first contact (e.g., contact affordance  704   b ), the electronic device causes audio output (e.g., audio output  630 ) of the first voice data. In some examples, in response to detecting activation of the first talk affordance (e.g., talk affordance  606 ), the electronic device captures first voice input at a microphone and sends, through the first communication channel, first outgoing data signal including first outgoing voice data corresponding to the captured first voice input. 
     At block  1006 , while the electronic device is connected to (e.g., active, open line) a first communication channel associated with a first external device (e.g., device  699   b ) of a first contact and not connected (e.g., inactive, closed line) to a second communication channel associated with a second external device (e.g., device  699   a ) of a second contact, the electronic device detects a touch input (e.g., touch input  702   c ) on the second affordance (e.g., contact affordance  704   a ). 
     At block  1008 , while the electronic device is connected to (e.g., active, open line) a first communication channel associated with a first external device (e.g., device  699   b ) of a first contact and not connected (e.g., inactive, closed line) to a second communication channel associated with a second external device (e.g., device  699   a ) of a second contact, the electronic device, subsequent to detecting the touch input (e.g., touch input  702   c ) on the second affordance (e.g., contact affordance  704   a ), disconnects from the first communication channel and connects to the second communication channel. For example, the electronic device disconnects in response to the touch input (e.g., touch input  702   c ) on the second affordance (e.g., contact affordance  704   a ), or in some examples after further touch input (e.g., touch input  620 ) on the talk affordance (e.g., talk affordance  606 ), and/or after a backend check that the second contact (e.g., contact affordance  704   a ) is available. 
     In accordance with some embodiments, the electronic device disconnects from the first communication channel and connects to the second communication channel in response to detecting the touch input (e.g., touch input  702   c ) on the second affordance (e.g., contact affordance  704   b ). Disconnecting from the first communication channel and connecting to the second communication channel in response to detecting the touch input allows the user to quickly switch communication channels with a single touch input. Reducing the number of inputs needed to perform an operation enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     At block  1010 , the electronic device displays a visual indication (e.g., indicators  608   y ,  608   z  in channel-switch mode  700 , and visual indicator  608  in the talk user interface  602 ) indicating that the device is not connected to the first communication channel and is connected to the second communication channel. For example, the electronic device switches visual borders (e.g., indicators  608   y ,  608   z ) from a first affordance (e.g., contact affordance  704   b ), to second affordance (e.g., contact affordance  704   a ), and swaps places of first affordance (e.g., contact affordance  704   b ) and second affordance (e.g., contact affordance  704   a ). Displaying the visual indication that the device is not connected to the first communication channel and is connected to the second communication channel provides the user with feedback that confirms which communication channel the device is connected to and which contact the user is in voice communications with when multiple contacts are displayed, and further provides visual feedback to the user indicating whether the user&#39;s request to switch communication channels has been implemented. Providing improved feedback enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, at block  1004 , while the electronic device is connected to the second communication channel and not connected to the first communication channel, the electronic device displays the second affordance (e.g., contact affordance  704   a ) and a second talk affordance (e.g., talk affordance  606 ) for communicating data through the second communication channel. 
     In accordance with some embodiments, while the electronic device is connected to the second communication channel and not connected to the first communication channel, the electronic device displays the second affordance (e.g., contact affordance  704   a ) and a second talk affordance (e.g., talk affordance  606 ) for communicating data through the second communication channel. For example, the electronic device displays the visual indication (e.g., visual indication  608 ) and displays the second affordance (e.g., contact affordance  704   a ) without displaying the first affordance (e.g., contact affordance  704   b ). 
     In accordance with some embodiments, subsequent to receiving a second data signal including second voice data at the second communication channel from the second contact (e.g., contact affordance  704   a ), the electronic device causes audio output (e.g., audio output  630 ) of the second voice data. In some examples, in response to detecting activation of the second talk affordance (e.g., talk affordance  606 ), the electronic device captures second voice input at the microphone and sends, through the second communication channel, second outgoing data signal including second outgoing voice data corresponding to the captured second voice input. 
     In accordance with some embodiments, in response to detecting the touch input (e.g., touch input  630   c ) on the second affordance (e.g., contact affordance  704   a ), the electronic device exits the channel-switch mode (e.g., channel switch mode  700 ). For example, a touch input (touch input  630   c ) on second affordance (e.g., contact affordance  704   a ) disconnects the first channel and connects to the second channel and exiting the channel-switch mode (e.g., channel switch mode  700 ) includes collapsing the first affordance (e.g., contact affordance  704   b ). In some examples, while the device is connected to the second communication channel and not connected to the first communication channel, in response to receiving a second user request (e.g., touch input  702   d ) to re-enter the channel-switch mode (e.g., channel switch mode  700 ), the electronic device concurrently displays the second affordance (e.g., contact affordance  704   a ) at the first position and the first affordance (e.g., contact affordance  704   b ) at the second position. 
     In accordance with some embodiments, while concurrently displaying the first affordance (e.g., contact affordance  704   b ) and the second affordance (e.g., contact affordance  704   a ) in response to receiving the second user request (e.g., touch input  702   d ), the electronic device displays a second visual indication (e.g., indicators  608   y ,  608   z ) that the device is connected to the second communication channel and not connected to the first communication channel, wherein the second visual indication (e.g., indicators  608   y ,  608   z ) is distinct from the visual indication (e.g., visual indication  608 ). For example, the second visual indication (e.g., indicators  608   y ,  608   z ) is two separate borders at the second affordance (e.g., contact affordance  704   a ) and the talk affordance (e.g., talk affordance  606 ), while the visual indication (e.g., visual indication  608 ) is a single border encompassing the second affordance (e.g., contact affordance  704   a ) and the talk affordance (e.g., talk affordance  606 ) when the device is not in channel-switch mode (e.g., channel switch mode  700 ). 
     In accordance with some embodiments, while concurrently displaying the first affordance (e.g., contact affordance  704   b ) and the second affordance (e.g., contact affordance  704   a ) in response to receiving the second user request (e.g., touch input  702   f ), in response to detecting a user intent (e.g., touch input  702   g ) to stay connected to the second communication channel, the electronic device exits the channel-switch mode (e.g., channel switch mode  700 ) and removes display of the first affordance (e.g., contact affordance  704   b ). For example, the user intent is a touch input (e.g., touch input  702   g ) on the first affordance (e.g., contact affordance  704   b ) or talk affordance (e.g., talk affordance  606 ), or a lack of touch input during channel-switch mode (e.g., channel switch mode  700 ) for a period of time). Further for example, the electronic device removes the first affordance (e.g., contact affordance  704   b ) while maintaining the second affordance (e.g., contact affordance  704   a ), and/or transitions display of the second visual indication (e.g., indicators  608   x ,  608   y ) back to the visual indication (e.g., visual indication  608 ). 
     In accordance with some embodiments, in response to detecting the user intent (e.g., touch input  702   g ), the electronic device replaces display of the second visual indication (e.g., indicators  608   x ,  608   y ) with the visual indication (e.g., visual indication  608 ). For example, the electronic device displays separate borders (e.g., indicators  608   x ,  608   y ) merging into single border (e.g., visual indication  608 ). 
     In accordance with some embodiments, while the device is connected to the second communication channel and not connected to the first communication channel, the electronic device concurrently displays the first affordance (e.g., contact affordance  704   b ) and the second affordance (e.g., contact affordance  704   a ) with an add affordance (e.g., add affordance  644 ) at a third position relative to the first position and the second position on the display, detects a second touch input (e.g., touch input  702   e ) on the add affordance (e.g., add affordance  644 ), subsequent to detecting the second touch input (e.g., touch input  702   e ) on the add affordance (e.g., add affordance  644 ), displays a contact list (e.g., contact list  678 ) including a third contact, and in response to detecting selection (e.g., touch input  682 ) of the third contact, disconnects from the second communication channel and connects to a third communication channel corresponding to a third external device (e.g., external device  699   c ) associated with the third contact. For example, while connecting, the electronic device displays a connection pending screen (e.g., contact pending screen  684  and/or connection pending screen  698 ) if the connection is slow to establish. 
     In accordance with some embodiments, while the device is connected to the third communication channel and is not connected to the second communication channel, in response to receiving a third user request (e.g., touch input  702   h ) to enter the channel-switch mode (e.g., channel switch mode  700 ), concurrently displaying a third affordance (e.g., contact affordance  704   c ) corresponding to the third contact at the first position, the second affordance (e.g., contact affordance  704   a ) at the second position, and the add affordance (e.g., add affordance  644 ) at the third position. For example, the third user request (e.g., touch input  702   h ) is a tap input on the third affordance (e.g., contact affordance  704   c ) representing the third contact. 
     In accordance with some embodiments, while connecting to the third communication channel subsequent to disconnecting from the second communication channel, the electronic device determines that the third communication channel cannot be connected, and in accordance with the determination that the third communication channel cannot be connected, ceases connecting to the third communication channel and enters an idle state (e.g.,  FIG. 7ED ) wherein the device is not connected to any communication channel. 
     In accordance with some embodiments, in accordance with the determination that the third communication channel cannot be connected, the electronic device displays a contact unavailable screen (e.g., contact unavailable screen  640 ). 
     Note that details of the processes described above with respect to method  1000  (e.g.,  FIG. 10 ) are also applicable in an analogous manner to the methods described above and below. For example, methods  900  and  1100  optionally include one or more of the characteristics of the various methods described above with reference to method  1000 . For example, methods  900  and  1100  can be combined with method  1000  to further include concurrently display a first affordance associated with the first contact and a second affordance associated with the second contact. For brevity, these details are not repeated below. 
       FIG. 11  is a flow diagram illustrating a method for communicating with others using an electronic device in accordance with some embodiments. Method  1100  is performed at a device (e.g.,  100 ,  300 ,  500 ) with a display with a touch-sensitive surface, such as a touch-sensitive display, and in some examples further with a microphone and speakers. Some operations in method  1100  are, optionally, combined, the order of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     As described below, method  1100  provides an intuitive way for communicating with others. The method reduces the cognitive burden on a user for communicating with others, thereby creating a more efficient human-machine interface. For battery-operated computing devices, enabling a user to communicating with others faster and more efficiently conserves power and increases the time between battery charges. 
     At block  1102 , the electronic device launches a voice communication application (e.g., application launch icon  652 , and/or  FIGS. 61A to 61B ). For example, the electronic device displays the voice communication application. 
     In accordance with some embodiments, at block  1104 , the electronic device launches the voice communication application automatically upon receiving incoming voice data from the external device (e.g., external device  699   a ) associated with the contact through the communication channel (e.g.,  FIGS. 61A to 61B ). Automatically launching the voice communication application upon receiving incoming voice data allows the user to quickly access the communication channel via the application (e.g., to see the source of the voice data and/or to respond to the sender) and enables the user to engage in the voice communications without requiring further input to gain access to the voice communications since the application is automatically displayed. Performing an operation when a set of conditions has been met without requiring further user input enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, the electronic device launches the voice communication application in response to detecting a first touch input (e.g., touch input  654 ) on an application icon (e.g., voice communication application launch icon  652 ) corresponding to the voice communication application on a home screen (e.g., home screen  650 ). 
     In accordance with some embodiments, the electronic device launches the voice communication application in response to detecting a second touch input (e.g., touch input  696 ) on an accept affordance (e.g., accept affordance  692 ) in an invitation alert (e.g., invitation screen  690 ). 
     In accordance with some embodiments, the electronic device launches the voice communication application in response to detecting a third touch input (e.g., touch input  674   d  on and/or touch input  674   e ) on a launch affordance (e.g., launch affordance  670 ) in an invitation declined alert (e.g., invitation status notification  6008  at  FIG. 6NF ). For example, the electronic device displays an invitation declined alert and detects a touch input on an icon that launches the application instead of only dismissing the alert. 
     In accordance with some embodiments, the electronic device launches the voice communication application in response to detecting a fourth touch input (e.g., touch input  674   d ) on a launch affordance (e.g., launch affordance  670 ) in an invitation accepted alert (e.g., invitation status notification  6008  at  FIG. 6KM ). 
     In accordance with some embodiments, subsequent to launching the application, the electronic device determines whether the communication channel between the device and the external device (e.g., external device  699   a ) meets availability criteria. For example, the electronic device determines whether a communication channel is available and/or already connected. Further for example, while the voice communication application is launched and/or while displaying the talk affordance  606 , the device continuously determines whether the communication channel is available. 
     At block  1106 , in accordance with a determination that a communication channel between the device and an external device (e.g., device  699   a ) associated with a contact meets a set of availability criteria, the electronic device displays a talk affordance (e.g., talk affordance  606 ) associated with the contact. For example, the electronic device checks if any communication channels are available to be connected to or are currently connected. Displaying the talk affordance associated with the contact if the device determines that the communication channel is available provides the user with feedback that voice communications can be exchanged with the contact since the contact is currently available. Providing improved feedback enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, the availability criteria include a first criterion that is met when the device receives a first indication that the external device has previously accepted the communication channel for communication via the application. For example, the electronic device receives an indication that a previous invitation (e.g., invitation screen  690   a ) was previously accepted and/or the external device (e.g., device  699   a ) was previously connected. 
     In accordance with some embodiments, the availability criteria include a second criterion that is met when the communication channel at the device is not in a do-not-disturb mode (e.g., do-not-disturb screen  656 ) and the device receives a second indication that the communication channel at the external device (e.g., device  699   a ) is not in the do-not-disturb mode (e.g., do-not-disturb screen  656   a ). For example, one or both of the devices  600 ,  699   a  are in the do-not-disturb mode in situations where either user is toggled-off or in a timeout period, when either device  600 ,  699   a  is not being worn if the device is a wearable device (e.g., a skin contact sensor at the device indicates a lack of physical skin contact), and/or when either device  600 ,  699   a  is in another phone or VoIP call. 
     In accordance with some embodiments, the availability criteria include a third criterion that is met when a network connectivity status at the device is a connected status, and the device receives a third indication that a network connectivity status at the external device (e.g., device  699   a ) is the connected status. For example, neither device is powered off or in an airplane mode setting where the device  600  or  699   a  is not connected to any networks. 
     In accordance with some embodiments, the availability criteria include a fourth criterion that is met when a notifications setting at the device is enabled, wherein notifications corresponding to alerts are not suppressed from output, and the device receives a fourth indication that a notifications setting at the external device (e.g.,  699   a ) is enabled. For example, neither device  600  nor  699   a  is in a do-not-disturb mode, a silent mode, or another type of mode that suppresses notifications from being output, including a theater mode and a sleep mode. 
     In accordance with some embodiments, the availability criteria include a fifth criterion that is met when the device receives a fifth indication that the external device (e.g., device  699   a ) is not currently connected to another communication channel. For example, external device  699   a  is not connected to another communication channel in the voice communications application at the device  699   a , and/or a third party application or phone call. 
     In accordance with some embodiments, while displaying the talk affordance (e.g., talk affordance  606 ) associated with the contact, the electronic device displays an availability toggle (e.g., switch  612 ) in an on position, wherein the device is connected to the communication channel when the availability toggle (e.g., switch  612 ) is in the on position. In some examples, in response to detecting a fifth touch input (e.g., touch input  660 ) at the availability toggle (e.g., switch  612 ) to change the on position to an off position, the device disconnects from the communication channel and enters a do-not-disturb mode (e.g., do-not-disturb screen  656 ), wherein the device is not available for communication via the voice communication application. For example, the electronic device replaces the talk affordance (e.g., talk affordance  606 ) with a do-not-disturb screen (e.g., do-not-disturb screen  656 ), and the communication channel no longer meets availability criteria. Further for example, the device enters in idle state wherein no communication channels are connected at the application. 
     In accordance with some embodiments, while the device is connected to the communication channel, the electronic device receives voice data from the external device (e.g., device  699   a ) and causes audio output (e.g., audio output  630 ) of the voice data. In some examples, in response to detecting the fifth touch input (e.g., touch input  660 ) while causing audio output (e.g., audio output  630 ) of the voice data, the electronic device ceases receiving the voice data or ceases audio output (e.g., audio output  630 ) of the voice data. For example, the electronic device interrupts audio output and/or stops receiving further voice data from device  699   a.    
     In accordance with some embodiments, in response to detecting a sixth touch input (e.g., touch input  660  at  FIG. 6OG ) at the availability toggle (e.g., switch  612 ) to change the off position to an on position, the electronic device exits the do-not-disturb mode (e.g., do-not-disturb mode  656 ), in accordance with a determination that the communication channel meets the set of availability criteria, the device connects to the communication channel and displays the talk affordance (e.g., talk affordance  606 ) while connected to the communication channel (e.g., connects to a most-recent channel), and in accordance with a determination that the communication channel does not meet the set of availability criteria, the device forgoes displaying the talk affordance (e.g., talk affordance  606 ) associated with the contact and enters an idle state wherein the device remains disconnected to the communication channel. For example, in the idle state, the device is not connected to any communication channels in the voice communications application. 
     In accordance with some embodiments, while displaying the talk affordance (e.g., talk affordance  606 ) associated with the contact, wherein the device is connected to the communication channel when the talk affordance (e.g., talk affordance  606 ) is displayed, determining whether the communication channel meets the availability criteria, and in accordance with a determination that the communication channel no longer meets the availability criteria, the device disconnects from the communication channel and ceases displaying the talk affordance (e.g., talk affordance  606 ). For example, when the contact at the external device  699   a  toggles off and/or loses network connectivity, the electronic device displays a contact unavailable screen (e.g., contact unavailable screen  640 ) and/or enters an idle state. 
     At block  1108 , in response to detecting a touch input (e.g., touch input  620 ) on the talk affordance (e.g., talk affordance  606 ) at the touch-sensitive display, the electronic device captures voice input. For example, the device captures voice input at a microphone (e.g., microphone  113 ). 
     At block  1110 , in response to detecting a touch input (e.g., touch input  620 ) on the talk affordance (e.g., talk affordance  606 ) at the touch-sensitive display, the electronic device sends voice data representing the voice input to the external device (e.g., device  699   a ) associated with the contact. For example, the electronic device sends live voice input to device  699   a.    
     In accordance with some embodiments, while the device is connected to the communication channel, the electronic device detects the touch input (e.g., touch input  620 ) on the talk affordance (e.g., talk affordance  606 ), and in accordance with the determination that the communication channel no longer meets the availability criteria while detecting the touch input (e.g., touch input  620 ) on the talk affordance (e.g., talk affordance  606 ), the device ceases sending voice data representing the voice input to the external device (e.g., device  699   a ). In some examples, the device also ceases to capture the voice output. 
     In accordance with some embodiments, while the device is connected to the communication channel and in accordance with the determination that the communication channel no longer meets the availability criteria, the device displays a contact unavailable screen (e.g., contact unavailable screen  604 ), and in accordance with a determination that the communication channel meets the set of availability criteria while displaying the contact unavailable screen (e.g., contact unavailable screen  604 ), the device connects to the communication channel and replaces display of the contact unavailable screen (e.g., contact unavailable screen  604 ) with the talk affordance (e.g., talk affordance  606 ) associated with the contact. In some examples, the electronic device reconnects to the contact&#39;s device  699   a.    
     At block  1112 , in accordance with a determination that the communication channel does not meet the set of availability criteria, the electronic device forgoes displaying the talk affordance (e.g., talk affordance  606 ). For example, the device launches the voice communication application and displays a do-not-disturb screen (do-not-disturb screen  656 , contact unavailable screen (e.g., contact unavailable screen  640 ), invite pending screen (e.g., contact pending screen  684 , connection pending screen  698 ), invite declined screen (e.g., contact declined screen  6010 ) and/or a first-time user setup screen (e.g., welcome screen  800 ). Forgoing displaying of the talk affordance when the communication channel is not available provides the user with feedback the function of capturing and sending voice to the contact is not an option at this time and provides visual feedback to the user indicating that the contact&#39;s device cannot receive voice communications through the communication channel at this time. Providing improved feedback enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, at block  1114 , in accordance with the determination that the communication channel does not meet the availability criteria, wherein the communication channel is not connected, the electronic device displays a status screen indicating a status of the communication channel, wherein the status screen comprises at least one of a contact unavailable screen (e.g., contact unavailable screen  640 ), an incoming invitation screen (e.g., invitation screen  690 ), an invitation pending screen (e.g., contact pending screen  684 , connection pending screen  698 ), and an invitation declined screen (e.g., contact declined screen  6010 ). Displaying a status screen when the communication channel is not available upon launch of the application provides the user with feedback about why the communication channel is not available and whether a connection is currently pending and provides visual feedback to the user indicating whether the communication channel may change to available under various circumstances described above and/or whether the user may have to communicate with the unavailable contact through other forms of communication. Providing improved feedback enhances the operability of the device and makes the user-device interface more efficient (e.g., by helping the user to provide proper inputs and reducing user mistakes when operating/interacting with the device) which, additionally, reduces power usage and improves battery life of the device by enabling the user to use the device more quickly and efficiently. 
     In accordance with some embodiments, in accordance with a determination that the communication channel meets the set of availability criteria while displaying the status screen, wherein the availability criteria include a sixth criterion that is met when the device receives a sixth indication that the status of the communication channel has changed, the electronic device connects to the communication channel and replaces display of the status screen with display of the talk affordance (e.g., talk affordance  606 ) associated with the contact. 
     In accordance with some embodiments, the status screen is the invitation pending screen (e.g., contact pending screen  684 , connection pending screen  698 ) and the criterion is met when the status changes from a pending-acceptance status to a contact-accepted status when the external device (e.g., device  699   a ) accepts connection to the communication channel. 
     In accordance with some embodiments, the status screen is the incoming invitation screen (e.g., invitation screen  690 ) including an accept affordance (e.g., accept affordance  692 ) and the criterion is met when the status changes from a pending-acceptance status to a user-accepted status in response to detecting a seventh touch input (e.g., touch input  697 ) on the accept affordance (e.g., accept affordance  692 ) to accept connection to the communication channel. 
     In accordance with some embodiments, subsequent to launching the application and in accordance with the determination that the communication channel does not meet the availability criteria, including a seventh criterion that is not met when the device has not previously connected to any communication channel via the application (e.g., and no pending invitations exist), the electronic device displays an add contacts user interface (e.g., welcome screen  800 , add screen  808 ), and subsequent to displaying the add contacts user interface (e.g., welcome screen  800 , add screen  808 ) and in response to detecting a first user request (e.g., touch input  682 ) to connect to a first contact, the device connects to a first communication channel associated with a first external device (e.g., device  699   a ) corresponding to the first contact. For example, the device displays a welcome screen  800  including a start affordance  804 , detects touch input  806   a  on the start affordance  804 , and transitions from the welcome screen  800  to add contacts user interface  808  including an add affordance  810 . Further for example, in response to detecting a touch input  806   b  on the add affordance  810 , the device displays a scrollable contacts list  678  including a plurality of contacts, and in response to selecting (e.g., touch input  682 ) the first contact of the plurality of contacts, the device connects to the first communication channel and replaces display of the scrollable contact list  678  with a status screen (e.g., contact pending screen  684 ) including a visual representation (e.g., visual representation  642 ) of the contact and an add affordance  644  for causing redisplay of the scrollable contacts list  678 . In some examples, the screen is an invitation pending screen 
     In accordance with some embodiments, while connecting to the first communication channel while the application is launched for display, in accordance with a determination that the first communication channel meets the set of availability criteria, the device displays a first talk affordance (e.g., talk affordance  606 ) associated with the first contact while the device is connected to the first communication channel, and in accordance with a determination that the first communication channel does not meet the set of availability criteria, wherein the first communication channel cannot be connected, the device ceases connecting to the first communication channel and displays an invitation declined screen (e.g., contact declined screen  6010 ). For example, the device replaces display of the invitation pending screen (e.g., contact pending screen  684 ) with at least one of the scrollable contact list  678  and a contact unavailable screen  640  that includes an add affordance  644  for causing redisplay of the scrollable contact list  678 . 
     In accordance with some embodiments, subsequent to detecting the first user request (e.g., touch input  682 ) to connect to the first contact and while the application is not currently launched for display, in accordance with a determination that the first external device (e.g., device  699   a ) has accepted connecting to the first communication channel, the electronic device displays an invitation accepted alert (e.g., invitation status notification  6008 , including a launch affordance  670  to launch the application and display the talk affordance  606  associated with a first affordance (e.g., contact affordance  604 ) representing the first contact), and in accordance with a determination that the first external device (e.g.,  699   a ) has declined connecting to the first communication channel, displaying an invitation declined alert (e.g., invitation status notification  6008  at  FIG. 6NF , including a dismiss affordance  672  to remove display of the notification  6008 ). 
     Note that details of the processes described above with respect to method  1100  (e.g.,  FIG. 11 ) are also applicable in an analogous manner to the methods described above. For example, methods  900  and  1000  optionally include one or more of the characteristics of the various methods described above with reference to method  1100 . For example, methods  900  and  1000  can be combined with method  1100  to further include that in accordance with a determination that the communication channel does not meet the set of availability criteria, the device foregoes displaying the talk affordance. For brevity, these details are not repeated below. 
       FIG. 12  is a block diagram illustrating a method of signal transmission between two electronic devices for electronic voice communication. The method of  FIG. 12  may be performed by any one of devices  100 ,  300 ,  500 ,  600 , and  699   a . Some operations in the method of  FIG. 12  are, optionally, combined, the order of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     While in a full-duplex live audio communication session (e.g., live audio communication session  1500 ) with an external device (e.g., device  600 ), the full-duplex live audio communication session configured to transmit control signal data (e.g., using control channel  1502 ) and separately transmit audio data (e.g., using media channel  1506 ), the electronic device receives control signal data (e.g., control signal data  1504 ) from the external device at block  1202 . In some embodiments, the control signal data is transmitted to the external device when the user activates a talk affordance (e.g., talk affordance  606 ) on the external device. Optionally, the control signal may be encoded in the application-specific data of a Real-Time Transfer Control Protocol (RTCP) signal. In some examples, the control signal data presents as a rising signal edge on a control channel (e.g., control channel  1502 , signal goes high from a default-low state). In other embodiments, the control signal data presents as an interruption in a steady-state high signal (e.g., a falling signal edge on control channel  1502 ) 
     At block  1204 , the electronic device issues a perceptual notification (e.g., perceptual notification  626   a ) in response to receiving the control signal. In some embodiments, the perceptual notification is an audio output (e.g., from speaker  113  on device  100 ), a visual notification on a touch display (e.g., touch screen  112 ), a haptic output, or any combination thereof. 
     Optionally, at block  1206 , the electronic device prevents audio input to a microphone (e.g., microphone  113  on device  699   a ) in response to receiving the control signal. In some embodiments, a touch affordance (e.g., touch affordance  606   a  on device  699   a ) allowing the user to enable the microphone is optionally disabled. In another such embodiment, the electronic device optionally mutes its uplink connection to a media channel (e.g., media channel  1506 ) in response to receiving the control signal data, thereby preventing second audio data (e.g., audio data  1610 ) from being sent to the external device. Since the control signal data is received before the audio data, disabling audio input to the microphone in this manner effectively prevents the electronic device from sending voice audio data to the external device immediately prior to receiving and while outputting the audio data. Alternatively and/or additionally, device  699   a  optionally does not transmit audio data on media channel  1506  while audio data  1510  is being received (e.g., device  699   a  may mute its uplink to media channel  1506 ). Optionally, the microphone, the transmitter, the analog-to-digital converter associated with the transmitter and/or the audio codec associated with the transmitter on device  699   a  are also powered down while receiving audio data  1510 , lowering or eliminating power on media channel  1506  and/or control channel  1510 . Thus, for the full-duplex live audio communication session between the electronic device and the external device (e.g., the session allows sending and receiving audio data simultaneously), disabling audio input in response to the control signal, under some circumstances, allows only one of the external device or the electronic device (e.g., devices  600  and  699   a ) to transmit audio data at any given time. 
     Optionally, at block  1208 , the electronic device prevents other applications (e.g., applications shown on home screen  650  of device  600 ) from issuing notifications (e.g., notifications  664   a ) for a third predetermined time period (e.g., until talk user interface  602  or  602   a  is no longer displayed, when talk affordance  606  or  606   a  is no longer being activated, and/or when voice data is not currently being output) in response to the receiving the control signal. For example, perceptual notifications from other applications suppressed in response to the control signal include audio, visual and/or haptic alerts corresponding to receipt of a text message, e-mail alert, and so on. Optionally, the suppressed perceptual notifications are then issued after the predetermined time period elapses or after the full-duplex live audio communication session between the external device and the electronic device is terminated. 
     At block  1210 , after a first predetermined time period (e.g., predetermined time period  1512 ) since receiving the control signal, the electronic device receives audio data (e.g., voice audio data  1510 ) from the external device. In some examples, the audio data is a digital data stream that encodes a voice signal (e.g., the voice signal picked up by the microphone (e.g., microphone  113 ) on external device  600  after activating talk affordance  606 ) and is interspersed in an existing audio data stream (e.g., the audio data steam transmitted over media channel  1506 ). During the full-duplex live audio communication session, baseline audio data (e.g., baseline audio data  1508 , a baseline signal from a muted microphone) is, in some cases, still transmitted even though it does not encode a voice signal. In this case, baseline audio data is, optionally, transmitted at a lower bit rate than the audio data, which may encode a voice signal. In some embodiments, the audio data and baseline audio data are compressed using MPEG, AWS, EVS, ACELD, or any other audio codec suitable for real-time applications. 
     At block  1212 , after a second predetermined time period (e.g., 100 ms, 150 ms, 250 ms, 500 ms, 1 s, etc.) since issuing the perceptual notification, the electronic device outputs the audio data from a speaker (e.g., speaker  111  on electronic device  699   a ). 
     In accordance with some embodiments, control signal data (e.g., control signal data  1504 ) is received on a first channel (e.g., control channel  1502 ) and audio data (e.g., voice audio data  1510 ) is received on a second channel (e.g., media channel  1506 ) that is different than the first channel during the full-duplex live audio communication session. 
     In accordance with some embodiments, the audio data (e.g., voice audio data  1510 ) comprises a plurality of audio data packets each having a header (e.g., RTP extension header, TCP extension header, non-audio encoding information) and a payload (e.g., RTP signal that encodes a voice signal). In some examples, the control signal data (e.g., control signal data  1504 ) is encoded in the header of at least one audio data packet in the plurality of audio data packets. In this case, the control signal data and audio data are received by the electronic device on the same channel. As an example, if audio data is transmitted to the electronic device according to the RTP standard, the corresponding control signal data is optionally encoded in the RTP extension header of the first RTP packet in the audio data stream. Alternatively and/or additionally, if audio data is transmitted to the electronic device according to the TCP standard, the corresponding control signal data is optionally encoded in the TCP extension header of the first TCP packet in the audio data steam. 
     In accordance with some embodiments, audio input to the microphone (e.g., microphone  113 ) is optionally enabled and second control signal data (e.g., control signal data  1604 ) is optionally output to the external device (e.g., device  600 ). In some embodiments, the audio input to the microphone is enabled in response to receiving a user input at the electronic device (e.g., user touch  620   a  that activates talk affordance  606   a ). In some embodiments, audio input to the microphone is enabled only if the user input is detected prior to receiving the control signal data (e.g., control signal  1504 ) from the external device or after playback of audio data sent by the external device (e.g., voice audio data  1510 ) has finished. 
     In accordance with some embodiments, audio input to the microphone is enabled a fourth predetermined time period (e.g., 100 ms, 150 ms, 250 ms, or any suitable time period, predetermined time period  1612 ) after receiving a user input (e.g., user touch  620   a  that activates talk affordance  606   a ). 
     In accordance with some embodiments, second audio data (e.g., audio data  1610 ) is output to the external device at a fourth predetermined time period (e.g., predetermined time period  1612 ) after outputting the second control signal data. For example, the second audio data is a digital data stream that encodes a voice signal (e.g., the voice signal picked up by the microphone (e.g., microphone  113 ) on electronic device  699   a  after activating talk affordance  606   a ) and is interspersed in an existing audio data stream (e.g., audio data transmitted over media channel  1606 ). In some cases, during the full-duplex live audio communication session, baseline audio data (e.g., baseline audio data  1608 , a baseline signal from a muted microphone) is still transmitted (e.g., on media channel  1606 ) even though it does not encode a voice signal. In this case, baseline audio data is, optionally, transmitted to the external device at a lower bit rate (e.g., sample rate) than the audio data. In some cases, the audio data and baseline audio data is compressed using MPEG, AWS, EVS, ACELD, or any other audio codec suitable for real-time applications. 
     In accordance with some embodiments, the device determines if the user input occurred before the control signal data (e.g., control signal data  1504 ) was generated based on clocking data (e.g., a time-stamp) within the control signal data. For example, if talk affordances  606  and  606   a  are activated on both the electronic device and the external device at roughly the same time, the external device (e.g., device  600 ), in some cases, detects user activation of the talk affordance before receiving the second control signal data (e.g., control signal data  1604 ), but after the talk affordance on the electronic device (e.g., device  699   a ) was activated. Under some circumstances, this timing conflict is caused by latency, the non-instantaneous nature of signal transmission, or a number of other factors. In these cases, it is necessary to determine whether the talk affordance of the external device was activated before the control signal data was generated by the sending device. In some examples, the result then determines which device transmits audio data (e.g., over media channel  1606 ) and which device&#39;s audio output is disabled. In the example above, determining if the user input that activated talk affordance  606   a  occurred before the control signal data (e.g., control signal  1504 ) was generated is, optionally, based on clocking data contained in the control signal data and/or the second control signal (e.g., control signal  1604 ). In some embodiments, the clocking data is a time stamp specifying the absolute time (e.g., time elapsed since a time predetermined by the signaling standard) at which the control signal data was generated. In other embodiments, the clock data is a time stamp specifying the time elapsed since the audio communication session between the electronic device and the external device was established. In some examples, the determination is performed if the time difference between the time-stamp of the control signal data (e.g., control signal data  1504 ) and the time-stamp of the second control signal data (e.g., control signal  1604 ) is less than the average signal transmission time between the electronic device and the external device. 
     In some embodiments, in accordance with a determination that the user input occurred before the control signal data (e.g., control signal data  1504 ) was generated, the electronic device enables audio input to the microphone (e.g., microphone  113 ) and forgo outputting the audio data (e.g., audio data  1510 ) from the speaker. In accordance with a determination that the user input occurred after the control signal data was generated, the electronic device optionally prevents audio input to the microphone from being enabled and outputs the audio data from the speaker. 
     In accordance with some embodiments, the first predetermined time period (e.g., predetermined time period  1512 ) and the second predetermined time period have different lengths. 
     In accordance with some embodiments, the first predetermined time period (e.g., predetermined time period  1512 ) has the same length as the second predetermined time period. 
     In accordance with some embodiments, the first and second audio data (e.g., audio data  1510  and audio data  1610 ) are transmitted according to a voice over internet protocol (VoIP) standard selected from the group consisting of: FaceTime Audio, Real-Time Transfer Protocol, Secure Real-Time Transfer Protocol, Universal Datagram Protocol, and Transmission Control Protocol. 
     In accordance with some embodiments, the first and second control signal data (e.g., control signal data  1504  and control signal data  1604 ) are transmitted according to a voice over internet protocol (VoIP) standard selected from the group consisting of: Real-Time Transfer Control Protocol, Real-Time Transfer Protocol, and Transmission Control Protocol. 
       FIG. 13  is a flow chart illustrating a method for initiating live audio communication sessions between two electronic devices for electronic voice communications. The method of  FIG. 13  is optionally performed by any one of devices  100 ,  300 ,  500 ,  600 , and  699   a . Some operations in the method of  FIG. 13  are, optionally, combined, the order of some operations are, optionally, changed, and some operations are, optionally, omitted. 
     At block  1302 , an electronic device (e.g., device  699   a ) receives, from an external device (e.g., device  600 ) associated with a contact (e.g., Aaron, John, Jane etc.) a request (e.g., session initiation protocol request signal) to establish a full-duplex live audio communication session (e.g., live audio communication session  1500 ) between the electronic device and the external device. For example, the request is, in some cases, a signal transmitted according to Session Initiation Protocol (SIP) that includes an INVITE request and a description unit specifying the media format of the full-duplex live audio communication session. In the example of  FIG. 6NB , the request is sent to the external device by the electronic device in response to detecting selection of Aaron Smith from contact list  678  by touch input  682 . 
     At block  1304 , the electronic device determines whether the contact is on a list (e.g., a whitelist representing a list of contacts associated with external devices with which the electronic device has established a communication session via the “Talk App” and/or contact list  678 ). 
     In accordance with a determination that the contact is on the list, the electronic device establishes the full-duplex audio communication session (e.g., connects to control channel  1502  and media channel  1506  allocated to the full-duplex audio communication session) between the electronic device and the external device at block  1306 . In particular, the electronic device establishes the full-duplex live audio communication session without receiving a user input (e.g., user touch  692 ) that acknowledges the request. 
     Optionally, at block  1308 , the electronic device disables audio input to a microphone (e.g., microphone  113 ) on the electronic device in response to establishing the full-duplex live audio communication session. In accordance with some embodiments, the microphone is disabled for a predetermined period of time (e.g., 1 s, 5 s, 10 s, 30 s, etc.) after establishing the full-duplex live audio communication session. In accordance with other embodiments, the audio input to the microphone is disabled until playback of audio data (e.g., voice audio data  1510 ) is finished playing back through a speaker (e.g., speaker  113 ) on the electronic device. In yet other embodiments, audio input to the microphone is disabled until a talk affordance on the electronic device (e.g., talk affordance  606   a ) is activated. 
     In accordance with a determination that the contact is not on the list, the electronic device waits for a user input (e.g., user touch  692  at touch screen  112 ) that accepts the request at block  1310  and establishes the full-duplex live audio communication session only if the user input is detected (e.g., at touch screen  112 ). 
     Optionally, at block  1312 , the electronic device establishes the full-duplex live audio communication session and adds the contact to the list in response to the detecting the user input. 
     Optionally, in response to establishing the full-duplex live audio communication after detecting the user input, the electronic device disables audio input to the microphone at block  1314 . 
     In accordance with some embodiments, in response to detecting an additional user input (e.g., touch input  682  that selects a contact from contact list  678 ), the electronic device sends a request (e.g., an SIP request) to establish a second full-duplex live audio communication session between the electronic device and a second external device (e.g., device  699   b ) associated with a second contact. In some examples, in response to sending the request to the second external device, the electronic device adds the additional contact to the whitelist (e.g., whitelist on device  600 ). For example, the request is, in some cases, a signal transmitted according to Session Initiation Protocol (SIP) that includes an INVITE request and a description unit specifying the media format of the full-duplex live audio communication session. 
     Referring now to a high-level discussion of exemplary receiver states (e.g., states of devices  600 ,  699   a , and/or  699   b  while performing processes  900 ,  1000 ,  1100 ,  1200  and/or  1300 ),  FIG. 14A  illustrates various states of a receiving device and transitions between those states. Before receiving a session initiation request (e.g., an SIP signal), the receiver device is in idle state  1400 . As an example, device  699   b  in  FIG. 6KA  is in idle state  1400  prior to receiving an incoming call. In idle state  1400 , talk user interface  602   b , request  6000   c , and any other affordances associated with the voice communication application are not displayed, and the receiving device (e.g.,  699   b ) is not connected to other devices over the voice communication application. 
     In response to receiving an incoming voice communication session request from an external device (e.g., at block  1302  of  FIG. 13 ), the receiving device determines whether or not the contact associated with that external device is on a whitelist (e.g., a list of vetted contacts the device has previously communicated with over the voice application) as discussed above (e.g., at block  1302  of  FIG. 13 ). If the contact is not whitelisted (e.g., is not on the whitelist, determined at block  1310  of  FIG. 13 ), the receiving device transitions to pre-active state  1402 . As an example, device  699   b  in  FIG. 6KJ  is in pre-active state  1402  after receiving a session initiation request from an external device (e.g., device  600 ) associated with non-whitelisted contact (e.g., John). In pre-active state  1402 , the device optionally waits for a user input that accepts the request and establish the audio communication session only if a user input that accepts the request is detected (e.g., at block  1310  of  FIG. 13 ). While waiting for a user input that accepts the request, the receiving device optionally displays an invitation screen (e.g., invitation screen  690   b ) that includes a visual indication of the call request, as well as affordances to either accept (e.g., accept affordance  692 ) or decline (e.g., decline affordance  694 ) the incoming call. In some cases, the receiving device optionally issues an audio, visual or haptic notification in response to receiving the incoming call (e.g., at block  1204  of  FIG. 12 ). In some examples, the receiving device also sends a response signal (e.g., an SIP response code) to the external device that acknowledges receipt of the session initiation request, but does not accept or decline. 
     In response to receiving a user input that accepts the request (e.g., user touch  696  at accept affordance  692  in  FIG. 6KK , block  1312  of  FIG. 13 ), the receiving device transitions to active state  1406 . As an example, device  699   b  in  FIG. 6KN  is in active state  1406 . In active state  1406 , the receiver device is connected to one or more communication channels allocated to a live audio communication session with the calling device (e.g., device  600 ). For example, the receiving device optionally connects to the calling (external) device via control channel  1502  and media channel  1506  shown in  FIG. 15 . In active state  1406 , the receiving device (e.g., device  699   b ) optionally receives and transmits audio and/or control data to/from the external device. In particular, while in active state  1406 , the receiving device optionally receives control signal data from the calling device (e.g., at block  1202  of  FIG. 12 ) and issues an additional perceptual notification (e.g., notification  630  at block  1204  of  FIG. 12 ) in response to receiving the control signal data. After a predetermined time since receiving the control signal data, while still in active state  1416 , the receiving device also receives audio data from the external device (e.g., audio data  1510  at block  1210  of  FIG. 12 ). After a second predetermined time period since issuing the additional perceptual notification and while still in active state  1416 , the receiving device outputs audio data received from the external device on a speaker (e.g., speaker  111 , block  1212  of  FIG. 12 ) While in active state  1406 , the receiving device optionally displays a talk user interface (e.g., talk user interface  602   b ), as well as a talk affordance (e.g., talk affordance  606   b ) that may be activated to transmit audio data to the external device (e.g., using microphone  113 ). In the example of  FIG. 14A , after disconnecting from the live audio communication session (e.g., due to time-out, exiting the voice communication application, etc.), or if network connectivity is lost, the receiving device returns to idle state  1400 . 
     In the example of  FIG. 14A , if the contact associated with the calling device is whitelisted (e.g., in response to determining that the contact is on a list at block  1304  of  FIG. 13 ), the receiving device transitions to auto-answer state  1404 . As an example, device  600  in  FIG. 6L-4  is in auto-answer state  1404 . While in auto-answer state  1404 , the receiving device optionally connects to one or more communication channels allocated to a live audio communication session with the calling device so that incoming audio data can be received. In some examples, device  600  also issues an audio, visual, and/or tactile notification (e.g., notification  626 ) indicating that the audio session is being established and audio data is incoming. After connecting to the one or more communication channels, the receiver device automatically transitions to active state  1406  without receiving a user input that acknowledges the session initiation request (e.g., establish the full-duplex live audio communication session at block  1306  of  FIG. 13 ). 
     Similarly,  FIG. 14B  illustrates exemplary states of a calling device (e.g., device  600 ,  699   a , and/or  699   b ) and transitions between those states (e.g., according to processes  1200  and  1300  in  FIGS. 12 and 13 ). Before opening the voice communication application or placing a call, the calling device is in an idle state  1410 . As an example, device  600  in  FIG. 6KA  is in idle state  1410 . In this state, the calling device is not connected to another device through the voice communication application, but optionally displays a contact list (e.g., contact list  678 ) representing contacts to which a call can be made. Alternatively, the calling device (e.g., device  600 ) optionally displays a home screen (e.g., home screen  650  in  FIG. 6KG ) or the user interface of another application besides the voice communication application. 
     In the example of  FIG. 14B , in response to selecting a contact associated with an external device (e.g., from contact list  678 ), the calling device transitions to calling state  1412 . As an example, device  600  in  FIG. 6KA  is shown in calling state  1412 . In this state, the calling device optionally displays a contact pending screen (e.g., contact pending screen  684 ), indicating that the calling device is waiting to connect. In some cases, while in calling state  1412 , the calling device (e.g., device  600 ) sends a session initiation request (e.g., an SIP request signal) to the external device (e.g., device  699   b ), and optionally connects to one or more communication channels allocated to a live audio communication session with the external device (e.g., control channel  1602  and media channel  1606  in  FIG. 16 ). 
     If the calling device is whitelisted by the receiving device, the calling device immediately transitions to active state  1416  (e.g., receiving device auto-accepts the session request sent at calling state  1412 ). As an example, device  600  in  FIG. 6KN  is in active state  1416 . In active state  1416 , both the calling device and receiving device are connected through the live audio communication session and may either transmit or receive media and/or control data (e.g., over media channel  1606  and control channel  1602 ). Calling device  600  optionally displays talk user interface  602  with talk affordance  606 , activation of which allows the user to send voice audio data to the receiving device (e.g., device  699   b ) as discussed above. In the example of  FIG. 14B , after disconnecting from the live audio communication session (e.g., due to time-out, exiting the voice communication application, etc.), or if network connectivity is lost, the calling device returns to idle state  1410   
     If the calling device is not whitelisted by the receiving device, the calling device transitions to pre-active state  1414  (e.g., after receiving an SIP response code from the receiving device acknowledging the SIP request sent at the calling state). Similar to calling state  1412 , the calling device optionally displays a contact pending screen such as contact pending screen  684  shown on device  600  in  FIG. 6KA . While in pre-active state  1414 , the calling device waits for a signal (e.g., an SIP response code) indicating that the receiving device either accepted or denied the session initiation request. 
     If the receiving device accepts the session initiation request, the calling device transitions to active state  1416  discussed above. 
     If the receiving device declines the session initiation request or otherwise becomes unavailable (e.g., due to network failure), the calling device transitions to unavailable state  1418 . As an example, device  600  in  FIG. 6MC  is in unavailable state  1418 . In this state, device  600  optionally displays contact declined screen  6010  (e.g., in the case that the receiver declined the request). Alternatively, the device optionally displays an indication that the contact is unavailable (e.g., contact unavailable screen  640   a  displayed on device  699   a  in  FIG. 6OC ) in the case that the receiver device is not connected to a network or is on another call. In the example of  FIG. 14B , the calling device then transitions back to idle state  1410 . For example, the device transitions back to idle state  1410  either at a predetermined time after entering unavailable state  1418 , or in response to the user exiting the voice communication application. However, if the receiving device later accepts the request within a predetermined time period (e.g., 5 m, 10 m, 30 m, or another suitable time period), the calling device optionally transitions directly into active state  1416 . In this example, the receiving device automatically answers a call returned by the receiver within a predetermined window. 
     The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the techniques and their practical applications. Others skilled in the art are thereby enabled to best utilize the techniques and various embodiments with various modifications as are suited to the particular use contemplated. 
     Although the disclosure and examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the disclosure and examples as defined by the claims. 
     As described above, one aspect of the present technology is the gathering and use of data available from various sources to improve the delivery to users of invitational content or any other content that may be of interest to them. The present disclosure contemplates that in some instances, this gathered data may include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, home addresses, or any other identifying information. 
     The present disclosure recognizes that the use of such personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver targeted content that is of greater interest to the user. Accordingly, use of such personal information data enables calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. 
     The present disclosure further contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. For example, personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection should occur only after receiving the informed consent of the users. Additionally, such entities would take any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services. In another example, users can select not to provide location information for targeted content delivery services. In yet another example, users can select to not provide precise location information, but permit the transfer of location zone information. 
     Therefore, although the present disclosure broadly covers use of personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing such personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. For example, content can be selected and delivered to users by inferring preferences based on non-personal information data or a bare minimum amount of personal information, such as the content being requested by the device associated with a user, other non-personal information available to the content delivery services, or publically available information.

Metadata:
Filing Date: 20191029
Publication Date: 20210504
Grant Date: 20210504
Priority Date: 20170516
Inventors: JOHNSON, HUGH W.
Garrido, Christopher
SCHOBEL, Andreas E.
Assignee: APPLE INC
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Family ID: 64272350