Patent Description:
Cellular telephones, computers, and other electronic equipment may generate audio signals during media playback operations and telephone calls. Users often use microphones and speakers in these devices to handle telephone calls and media playback. Sometimes ear buds have cords that allow the ear buds to be plugged into an electronic device.

Wireless ear buds provide users with more flexibility than wired ear buds, but can be challenging to use. It is not always clear whether a wireless ear bud is located in a pocket, is resting on a table, or is in a user's ear. As a result, audio signals can sometimes be misdirected.

It would therefore be desirable to be able to provide improved wearable electronic devices such as improved wireless ear buds.

Ear buds are provided that communicate wirelessly with an electronic device. The electronic device may be a cellular telephone, wristwatch device, or other electronic equipment. A wireless link may be established between the electronic device and the ear buds. The wireless link may be used to transfer audio information between the ear buds and the electronic device. For example, if the electronic device is being used for a cellular telephone call or media playback operations, audio associated with the cellular telephone call or media playback operations may be transferred between the electronic device and the ear buds over the wireless link.

The state of the ear buds may be monitored and corresponding actions taken in controlling the ear buds and electronic device. For example, if a user places an ear bud in the ear of the user in response to receiving a cellular telephone call with the electronic device, the telephone call can be automatically transferred to the ear bud. If the user removes the ear bud from the ear during a telephone call or media playback operation, the audio for the call or media playback operation can be routed to a speaker in the electronic device.

During use by a user, the ear buds may be stored in a case or pocket, may be rest on a table top, may be inserted into the ear of a user, or may rest in the ear of a user. To determine the current status of the ear buds and thereby take suitable action in controlling the operation of the electronic device and ear buds, the ear buds may be provided with sensor circuitry. The sensor circuitry may include proximity sensors. The ear buds may each have a main body portion that is configured to be inserted into the ear of the user and an elongated stem portion that extends from the main body portion. The proximity sensors may include sensors on the main body and sensors on the stem.

The proximity sensors may be light-based sensors each of which has a light source such as an infrared light-emitting diode and a corresponding light detector. Infrared light from the light-emitting diodes can pass through the housings of the ear buds. There may be two proximity sensors on the main body of each ear bud and two proximity sensors on the stem of each ear bud or other numbers of proximity sensors may be used. The present invention defines an ear bud as set forth in independent claim <NUM>.

An electronic device such as a host device may have wireless circuitry. Wireless wearable electronic devices such as wireless ear buds may communicate with the host device and with each other. In general, any suitable types of host electronic device and wearable wireless electronic devices may be used in this type of arrangement. The use of a wireless host such as a cellular telephone, computer, or wristwatch may sometimes be described herein as an example. Moreover, any suitable wearable wireless electronic devices may communicate wirelessly with the wireless host. The use of wireless ear buds to communicate with the wireless host is merely illustrative.

A schematic diagram of an illustrative system in which a wireless electronic device host communicates wirelessly with accessory devices such as ear buds is shown in <FIG>. Host electronic device <NUM> may be a cellular telephone, may be a computer, may be a wristwatch device or other wearable equipment, may be part of an embedded system (e.g., a system in a plane or vehicle), may be part of a home network, or may be any other suitable electronic equipment. Illustrative configurations in which electronic device <NUM> is a watch, computer, or cellular telephone, may sometimes be described herein as an example.

As shown in <FIG>, electronic device <NUM> may have control circuitry <NUM>. Control circuitry <NUM> may include storage and processing circuitry for supporting the operation of device <NUM>. The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry <NUM> may be used to control the operation of device <NUM>. The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc..

Device <NUM> may have input-output circuitry <NUM>. Input-output circuitry <NUM> may include wireless communications circuitry <NUM> (e.g., radio-frequency transceivers) for supporting communications with wireless wearable devices such as ear buds <NUM> or other wireless wearable electronic devices via wireless links <NUM>. Ear buds <NUM> may have wireless communications circuitry <NUM> for supporting communications with circuitry <NUM> of device <NUM>. Ear buds <NUM> may also communicate with each other using wireless circuitry <NUM>. In general, the wireless devices that communicate with device <NUM> may be any suitable portable and/or wearable equipment. Configurations in which wireless wearable devices <NUM> are ear buds are sometimes described herein as an example.

Input-output circuitry in device <NUM> such as input-output devices <NUM> may be used to allow data to be supplied to device <NUM> and to allow data to be provided from device <NUM> to external devices. Input-output devices <NUM> may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, displays (e.g., touch screen displays), tone generators, vibrators (e.g., piezoelectric vibrating components, etc.), cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device <NUM> by supplying commands through input-output devices <NUM> and may receive status information and other output from device <NUM> using the output resources of input-output devices <NUM>. If desired, some or all of these input-output devices may be incorporated into ear buds <NUM>.

Each ear bud <NUM> may have control circuitry <NUM> (e.g., control circuitry such as control circuitry <NUM> of device <NUM>), wireless communications circuitry <NUM> (e.g., one or more radio-frequency transceivers for supporting wireless communications over links <NUM>), may have one or more sensors <NUM>, and may have additional components such as speakers <NUM>, microphones <NUM>, and accelerometers <NUM>. Speakers <NUM> may play audio into the ears of a user. Microphones <NUM> may gather audio data such as the voice of a user who is making a telephone call. Accelerometer <NUM> may detect when ear buds <NUM> are in motion or are at rest.

Control circuitry <NUM> on ear buds <NUM> and control circuitry <NUM> of device <NUM> may be used to run software on ear buds <NUM> and device <NUM>, respectively. During operation, the software running on control circuitry <NUM> and/or <NUM> may be used in gathering sensor data, user input, and other input and may be used in taking suitable actions in response to detected conditions. As an example, control circuitry <NUM> and <NUM> may be used in handling audio signals in connection with incoming cellular telephone calls when it is determined that a user has placed one of ear buds <NUM> in the ear of the user. Control circuitry <NUM> and/or <NUM> may also be used in coordinating operation between a pair of ear buds <NUM> that are paired with a common host device (e.g., device <NUM>), handshaking operations, etc..

In some situations, it may be desirable to accommodate stereo playback from ear buds <NUM>. This can be handled by designating one of ear buds <NUM> as a primary ear bud and one of ear buds <NUM> as a secondary ear bud. The primary ear bud may serve as a slave device while device <NUM> serves as a master device. A wireless link between device <NUM> and the primary ear bud may be used to provide the primary ear bud with stereo content. The primary ear bud may transmit one of the two channels of the stereo content to the secondary ear bud for communicating to the user (or this channel may be transmitted to the secondary ear bud from device <NUM>). Microphone signals (e.g., voice information from the user during a telephone call) may be captured by using microphone <NUM> in the primary ear bud and conveyed wirelessly to device <NUM>.

Sensors <NUM> may include strain gauge sensors, proximity sensors, ambient light sensors, touch sensors, force sensors, temperature sensors, pressure sensors, magnetic sensors, accelerometers (see, e.g., accelerometers <NUM>), gyroscopes and other sensors for measuring orientation (e.g., position sensors, orientation sensors), microelectromechanical systems sensors, and other sensors. Proximity sensors in sensors <NUM> may emit and/or detect light and/or may be capacitive proximity sensors that generate proximity output data based on measurements by capacitance sensors (as examples). Proximity sensors may be used to detect the presence of a portion of a user's ear to ear bud <NUM> and/or may be triggered by the finger of a user (e.g., when it is desired to use a proximity sensor as a capacitive button or when a user's fingers are gripping part of ear bud <NUM> as ear bud <NUM> is being inserted into the user's ear).

<FIG> is a perspective view of an illustrative ear bud. As shown in <FIG>, ear bud <NUM> may include a housing such as housing <NUM>. Housing <NUM> may have walls formed from plastic, metal, ceramic, glass, sapphire or other crystalline materials, fiber-based composites such as fiberglass and carbon-fiber composite material, natural materials such as wood and cotton, other suitable materials, and/or combinations of these materials. Housing <NUM> may have a main portion such as main body <NUM>-<NUM> that houses audio port <NUM> and a stem portion such as stem <NUM>-<NUM> or other elongated portion that extends away from main body portion <NUM>-<NUM>. During operation, a user may grasp stem <NUM>-<NUM> and, while holding stem <NUM>-<NUM>, may insert main portion <NUM>-<NUM> and audio port <NUM> into the ear.

Audio ports such as audio port <NUM> may be used for gathering sound for a microphone and/or for providing sound to a user (e.g., audio associated with a telephone call, media playback, an audible alert, etc.). For example, audio port <NUM> of <FIG> may be a speaker port that allows sound from speaker <NUM> (<FIG>) to be presented to a user. Sound may also pass through additional audio ports (e.g., one or more perforations may be formed in housing <NUM> to accommodate microphone <NUM>).

Sensor data (e.g., proximity sensor data, accelerometer data or other motion sensor data), wireless communications circuitry status information, and/or other information may be used in determining the current operating state of each ear bud <NUM>. Proximity sensor data may be gathered using proximity sensors located at any suitable locations in housing <NUM>. <FIG> is a side view of ear bud <NUM> in an illustrative configuration in which ear bud <NUM> has four proximity sensors S1, S2, S3, and S4. Sensors S1 and S2 may be mounted in main body portion <NUM>-<NUM> of housing <NUM> and sensors S3 and S4 may be mounted on stem <NUM>-<NUM> or other mounting arrangements may be used. In the example of <FIG>, there are four proximity sensors on housing <NUM>. More proximity sensors or fewer proximity sensors may be used in ear bud <NUM>, if desired.

Sensors S1, S2, S3, and S4 may use reflected light, capacitance measurements, or other measurements to determine whether an external object is nearby. During operation, a raw sensor signal (e.g., a reflected light signal, capacitance signal, etc.) may be compared to a predetermined threshold. If the raw signal is greater than the threshold, the sensor output will be positive (i.e., an external object is in the vicinity of the sensor). If the raw signal is less than the threshold of the sensor, the sensor output will be negative (i.e., no external object is in the vicinity of the sensor).

As shown in <FIG>, ear bud <NUM> may be inserted into the ear (ear <NUM>) of a user, so that speaker port <NUM> is aligned with ear canal <NUM>. Ear <NUM> may have features such as concha <NUM>, tragus <NUM>, and antitragus <NUM>. Proximity sensors such as proximity sensors S1 and S2 may output positive signals when ear bud <NUM> is inserted into ear <NUM>. Sensor S1 may be a tragus sensor and sensor S2 may be a concha sensor or sensors such as sensors S1 and/or S2 may be mounted adjacent to other portions of ear <NUM>. Sensors S3 and S4 may be located away from ear <NUM>, so that sensors S3 and S4 output negative signals when ear bud <NUM> is inserted into ear <NUM>.

The status of sensors S1, S2, S3, and S4 may be analyzed to help discriminate between possible usage scenarios for ear buds <NUM> (e.g., an ear bud is in a protective case, an ear bud is in a user's pocket, an ear bud is being held by the fingers of a user as the user is inserting the ear bud into ear <NUM>, ear bud <NUM> is in ear <NUM>, etc.). Based on this status information, appropriate action can be taken by ear buds <NUM> and electronic device <NUM>.

With one illustrative arrangement, proximity sensors in ear buds <NUM> may be formed using light-based proximity sensors. An illustrative light-based proximity sensor that has been mounted within housing <NUM> of ear bud <NUM> is shown in <FIG>. As shown in the cross-sectional side view of <FIG>, light-based proximity sensor <NUM> may have a substrate such as substrate <NUM>. Substrate <NUM> may be formed from a rigid printed circuit board (e.g., substrate <NUM> may be formed from fiberglass-filled epoxy or other rigid printed circuit board material) or may be a flexible printed circuit (e.g., substrate <NUM> may be formed from a flexible layer of polyimide or a sheet of other flexible polymer). Components may be mounted on substrate <NUM> for handling proximity sensor signals. These components may include light source <NUM> and light detectors <NUM>.

Light source <NUM> may be a light-emitting diode such as an infrared light-emitting diode that emits light <NUM> that is out of the visible spectrum (e.g., to avoid distracting the user). Light detector <NUM> may be a photodetector based on a phototransistor or photodiode and may be sensitive to the wavelength of light <NUM>. In the absence of ear <NUM> or other external object such as external object <NUM> (e.g., a user's finger, the interior of a pocket, a table top, etc.), light <NUM> will travel into free space and will not be reflected towards detector <NUM>. As a result, the output of sensor <NUM> will be negative. In the presence of ear <NUM> or other external object <NUM>, however, reflected light <NUM> from external object <NUM> will be detected by detector <NUM>. The output of sensor <NUM> in this situation will therefore be positive. Light <NUM> (and reflected light <NUM>) may be visible light, infrared light, broad spectrum light, narrow spectrum light (e.g., light having a spectral width of less than <NUM> or less than <NUM>), may be ultraviolet light, or may be other suitable light.

Sensor <NUM> may be mounted behind a portion of housing wall <NUM>. In the illustrative configuration of <FIG>, portions 40D of housing wall <NUM> are different than portions 40W of housing wall <NUM>. Portions 40D may absorb light <NUM> and may therefore reduce the signal-to-noise ratio of reflected signal <NUM>. To enhance the signal-to-noise ratio of proximity sensor <NUM>, infrared-transparent materials may be used in forming windows in housing <NUM>. For example, portions 40W may be infrared-transparent materials (e.g., plastic, glass, etc.), may be portions of housing <NUM> that include microperforations to enhance infrared light transmission (e.g., laser-drilled openings with diameters of less than <NUM> microns, more than <NUM> microns, less than <NUM> microns, or other suitable sizes), or may be other material or structures for enhancing the transmission of light <NUM> and the transmission of reflected light <NUM>.

Some of light <NUM> may scatter when emitted by light source <NUM>, so an optional light blocking structure such as structure <NUM> may be incorporated into sensor <NUM>, if desired. Structure <NUM> may be formed from opaque plastic, metal, or other opaque materials. Structure <NUM> may be formed as an integral portion of housing <NUM>, may be a molded plastic member on substrate <NUM>, may be a member that is attached to substrate <NUM> using adhesive or other suitable mounting arrangements, or may be any other light blocking structure. Clear polymer or other material may be interposed between light source <NUM> and housing <NUM> and may be interposed between housing <NUM> and light detector <NUM>. The illustrative configuration of <FIG>, which does not include any polymer or other material between the circuitry of sensor <NUM> and the inner surface of housing <NUM>, is shown as an example.

<FIG> is a cross-sectional side view of housing <NUM> and sensor <NUM> in an illustrative configuration in which a portion of housing <NUM> has been locally thinned to enhance light transmission for sensor <NUM>. Housing <NUM> has a thickness of D2 in regions of ear bud <NUM> that are not aligned with sensor <NUM>. In portions of housing <NUM> that are aligned with sensor <NUM>, housing <NUM> is locally thinned and has a thickness D1 that is less than D2. The value of D2 may be <NUM> microns, more than <NUM> microns, more than <NUM> microns, less than <NUM>, or other suitable thickness. The value of D1 may be <NUM> microns, more than <NUM> microns, less than <NUM> microns, or other suitable thickness). Illustrative polymer <NUM> (e.g., infrared-transparent polymer) or other structures may be placed between substrate <NUM> and the inner surface of thinned portion 40T of housing <NUM> to help secure sensor <NUM> to ear bud <NUM> or other mounting techniques may be used.

Some of light <NUM> may be scattered into detector <NUM> by particles or other substances in housing <NUM>. Calibration operations may be performed during manufacturing or during use of ear bud <NUM> by a user to remove this source of noise from the proximity detector signal produced by sensor <NUM>. Illustrative steps involved in the calibration and use of proximity sensor data in ear buds <NUM> is shown in <FIG>. During calibration operations (step <NUM>), the amount of light <NUM> that is being scattered back towards detector <NUM> by housing <NUM> rather than being reflected back towards detector <NUM> by an external object can be ascertained. In particular, the amount of light <NUM> that is scattered rather than being transmitted may be measured at step <NUM>. For example, light source <NUM> may be modulated using a square wave or other suitable modulating signal in the absence of an external object. When light source <NUM> is turned on, detector <NUM> can measured the scattered light signal from housing <NUM>. When light source <NUM> is turned off, detector <NUM> will measure background signals. Using this technique, the amount of scattered light in sensor <NUM> (e.g., a fraction of the amount of transmitted light <NUM>) may be determined and stored in control circuitry <NUM> for use as calibration data (see, e.g., step <NUM>).

At step <NUM>, after the calibration operations of step <NUM> have been performed, ear bud <NUM> may be used by a user while data is gathered from proximity sensors S1, S2, S3, and S4 and other sensors and circuitry in ear buds <NUM>. The user may store ear buds <NUM> in a protective charging case (e.g., a case having a connector that mates with a corresponding connector on stem <NUM>-<NUM> or other portion of ear bud <NUM> to facilitate battery recharging operations), may store ear buds <NUM> in a pocket of an article of clothing or a bag, may allow ear buds <NUM> to rest on a surface such as a table top, may pick up and hold ear buds <NUM> by body <NUM>-<NUM> and/or stem <NUM>-<NUM>, may insert ear buds <NUM> into ears <NUM>, and may remove ear buds <NUM> from ears <NUM>.

In each of these different possible usage scenarios, there is a potential for a different set of sensors to be blocked and a potential for a corresponding different set of sensors to be unblocked. The amounts of time that the sensors are blocked and unblocked will also generally vary in different scenarios.

Sensors may be blocked by ears <NUM>, by a user's fingers, by a portion of a pocket of a case or article of clothing, by a table surface of other resting surface, etc. For example, if sensors S1 and S2 are positive and sensors S3 and S4 are negative, ear buds <NUM> and device <NUM> can conclude that ear buds <NUM> have been inserted into ears <NUM> (i.e., sensors S1 and S2 are now resting adjacent to ear <NUM> and sensors S3 and S4 are uncovered because the user's fingers have released the stems of ear buds <NUM>). If sensors S1, S2, S3, and S4 are all negative (as another example), it can be concluded that ear buds <NUM> are in an enclosed area such as the interior of a pocket.

Accelerometer data from accelerometer <NUM> and/or other information (e.g., information from microphone <NUM>) may be used to help accurately identify usage scenarios. As an example, if accelerometer <NUM> indicates that ear buds <NUM> are not moving, it can be concluded that ear buds <NUM> are resting on a table or other non-moving surface. If accelerometer <NUM> indicates that ear buds <NUM> are moving, it can be assumed that ear buds <NUM> are not resting on a table. Clock data (e.g., time information, date information, etc.) may be used in conjunction with sensor data, communications status data (e.g., whether an incoming cellular telephone is being received by device <NUM>), and other information to determine which actions should be taken by ear buds <NUM> and device <NUM>.

At step <NUM>, ear buds <NUM> and/or device <NUM> of <FIG> may take suitable action based on the detected state of ear buds <NUM>. For example, if it is determined that a user has just placed one of ear buds <NUM> into ear <NUM> in response to an incoming cellular telephone call to device <NUM>, audio playback may be transferred from device <NUM> to that ear bud. A remote wireless link (e. , a cellular telephone link with a wireless base station in a cellular telephone network) may be handled by device <NUM>. A local wireless link (link <NUM> of <FIG>) may be established between device <NUM> and ear bud <NUM> to allow ear bud <NUM> to transmit and receive audio. If it is determined that ear buds <NUM> are located in the pocket of a user when an incoming call is received on device <NUM>, the incoming call can be routed to the speaker and microphone of device <NUM>.

In yet another scenario, a user may be using ear bud <NUM> in ear <NUM> to handle a cellular telephone call. A local wireless link (link <NUM>) between ear bud <NUM> and device <NUM> may be used to transmit microphone and speaker audio signals between device <NUM> and ear bud <NUM>. Device <NUM> may maintain a cellular telephone link with remote network equipment. If a user removes ear bud <NUM> from ear <NUM> during the telephone call, the microphone and speaker of device <NUM> can be switched into use so that the telephone call can be sustained even though the user is no longer using ear bud <NUM>.

In some situations, the output of sensor S1 may be positive while sensors S3 and S4 are negative, indicating that ear bud <NUM> is in ear <NUM>. During media playback, audio may be streamed from device <NUM> to ear bud <NUM> and presented to the user with the speaker in ear bud <NUM>. Sensors S3 and S4 may be used as touch buttons. A user can momentarily block one or both of these sensors to advance a track, to pause a track that is currently playing, or to otherwise control media playback. As this example demonstrates, temporarily unused proximity sensors can serve as input devices.

To discriminate between different usage states, control circuitry <NUM> and/or control circuitry <NUM> may analyze sensor data from each of the proximity sensors in ear buds <NUM> and/or the sensors and other circuitry of ear buds <NUM> and device <NUM>. An illustrative state diagram showing the operation of the system of <FIG> in different states is shown in <FIG>. Control circuitry <NUM> and/or control circuitry <NUM> may determine the current operating state of the <FIG> system (e.g., ear buds <NUM> and/or device <NUM>) by analyzing the output of sensors S1, S2, S3, and S4 and, if desired, additional sensors and sources of operational state information in ear buds <NUM> and device <NUM>.

In state <NUM>, ear bud <NUM> is not in ear <NUM>. While ear bud <NUM> is out of the user's ear, the status of sensors S1, S2, S3, and S4 may be monitored. So long as S1 and S2 are not positive while S3 and S4 are negative, it can be concluded that ear bud <NUM> is remaining out of the user's ear (i.e., in state <NUM>). Monitoring of S1, S2, S3, and S4 may therefore continue.

In response to detecting a positive output from sensors S1 and S2 and a negative output from sensors S3 and S4, it can be tentatively concluded that ear bud <NUM> has been placed in ear <NUM> in a configuration of the type shown in <FIG> and that the user has released stem <NUM>-<NUM>. Operations may therefore transition to state <NUM> (a state representing the transition of ear bud <NUM> into ear <NUM>), as indicated by line <NUM>. During state <NUM>, the status of sensors S1, S2, S3, and S4 can be monitored to determine whether the positive state of sensors S1 and S2 and the negative state of sensors S3 and S4 will be sustained for a threshold amount of time (time T2). The value of T2 may be <NUM> seconds, more than <NUM> seconds, less than <NUM> second, or other suitable length of time. If any of the outputs of sensors S1, S2, S3, and S4 changes during state <NUM>, it can be concluded that ear bud <NUM> is not in ear <NUM> and operations may transition back to state <NUM>, as indicated by line <NUM>.

If sensors S1 and S2 remain positive and sensors S3 and S4 remain negative for time T2, it can be concluded that ear bud <NUM> is in ear <NUM> and operations can transition to state <NUM>, as indicated by line <NUM>. During the monitoring operations of state <NUM>, the status of sensor S1 (the tragus sensor) or sensor S2 (the concha sensor) can be monitored and the status of sensors S3 and S4 can be ignored. After ear bud <NUM> has been placed in ear <NUM>, a user may move in a way that causes sensors S3 and S4 to produce a positive output (e.g., due to the presence of hair, a hat, or other obstructions). The output of sensors S3 and S4 is therefore not necessarily representative of the status of ear bud <NUM> during use of ear bud <NUM> and can be ignored when monitoring the sensors to determine the current operating state of ear bud <NUM>. Sensors such as sensors S1 and S2 are immediately adjacent to the user's ear and are therefore more representative of whether or not ear bud <NUM> is in the user's ear. With one illustrative configuration, sensor S1 may be monitored and sensor S2 may be ignored along with sensors S3 and S4 (e.g., because sensor S1 is more representative of whether or not ear bud <NUM> is present in ear <NUM>). Other sensor monitoring schemes may be used during state <NUM>, if desired (e.g., schemes in which S2 is monitored but not S1, schemes in which S1 and S2 are monitored, schemes in which S1 and S2 are both monitored but are weighted unequally and/or are filtered using different time-dependent filters, etc.). The arrangement of state <NUM> of <FIG> is an example.

In a scenario in which sensor S1 is being monitored during state <NUM> while the outputs of sensors S2, S3, and S4 are being ignored, any transition in the state of the output of sensor S1 from positive to negative indicates that ear bud <NUM> is potentially being removed from ear <NUM>. Operations may therefore transition to state <NUM>, as indicated by line <NUM>.

During the operations of state <NUM>, ear bud <NUM> is believed to be transitioning out of ear <NUM>. In response to determining during the operations of step <NUM> that the S1 sensor output has returned to positive before reaching time T1, operations may transition back to state <NUM>, as indicated by line <NUM> (i.e., it can be concluded that ear bud <NUM> is still in ear <NUM>). The value of T1 may be <NUM> seconds, less than <NUM> second, more than <NUM> second, or other suitable amount. The value of T1 may be less than the value of T2 or may be more than the value of T2. If the output of sensor S1 remains negative for a predetermined threshold amount of time (e.g., more than time T1), it can be concluded that ear bud <NUM> is out of ear <NUM> and operations can transition to state <NUM>.

Information from the monitoring operations and analysis operations of <FIG> can be used to determine which actions to take during the operations of step <NUM> (<FIG>). If desired, other sensor data (e.g., accelerometer output), cellular telephone call status information (incoming call present, current call active, etc.), and/or other communications status information and operating status information may be used in determining which actions to take. The user of proximity sensor output information from sensors S1, S2, S3, and S4 is merely illustrative.

In accordance with an embodiment a wireless ear bud is provided that includes a housing, a speaker in the housing, a concha sensor in the housing, tragus sensor in the housing, and an accelerometer in the housing that is configured to produce output indicative of movement of the housing.

In accordance with another embodiment, the concha and tragus sensors include light-based proximity sensors.

In accordance with another embodiment, the concha and tragus sensors each have an infrared light-emitting diode and each have a light detector.

In accordance with another embodiment, the housing includes a wall and the infrared light-emitting diodes in the concha and tragus sensors emit infrared light that passes through the wall.

In accordance with another embodiment, the wireless ear bud has a current operating state, the wireless ear bud includes control circuitry that is configured to determine the current operating state by analyzing output from at least the concha and tragus sensors.

In accordance with another embodiment, the control circuitry is further configured to determine the current operating state by analyzing output from the accelerometer.

In accordance with another embodiment, the concha and tragus sensors include respective infrared light-emitting diodes.

In accordance with another embodiment, the housing has a first portion that is configured to be inserted into an ear and a second portion that extends from the first portion, the first portion has infrared-transparent portions, and the infrared light from the infrared light-emitting diodes passes through the infrared-transparent portions.

In accordance with another embodiment, the infrared-transparent portions include plastic and the concha sensor is configure to detect infrared light that has reflected off of a concha of the ear.

In accordance with another embodiment, the housing has a first portion that is configured to be inserted into an ear and a second portion that extends from the first portion, the wireless ear bud includes an infrared light-based proximity sensor in the second portion.

In accordance with an embodiment, an ear bud is provided that includes control circuitry, wireless circuitry that the control circuitry uses to communicate wirelessly with an electronic device, a housing having a main body portion that is configured to be inserted into an ear of a user and a stem portion that extends from the main body portion, a speaker in the main body portion, a first proximity sensor on the main body portion that monitors whether the first proximity sensor is adjacent to the ear and a second proximity sensor on the stem portion.

In accordance with another embodiment, when the main body portion is in the ear, the first proximity sensor produces a positive output indicating that the first proximity sensor is adjacent to the ear and the second proximity sensor produces a negative output indicating that no external object is adjacent to the second proximity sensor.

In accordance with another embodiment, the first proximity sensor is a light-based proximity sensor.

In accordance with another embodiment, the second proximity sensor is a light-based proximity sensor.

In accordance with another embodiment, the first and second proximity sensors each include an infrared light-emitting diode and the infrared light-emitting diodes produce infrared light that passes through the housing, the ear bud includes an accelerometer in the housing.

In accordance with an embodiment, an ear bud is provided that includes a housing having a main body portion and a stem portion that extends from the main body portion, a speaker in the main body portion, and at least two proximity sensors on the housing.

In accordance with another embodiment, the proximity sensors include first and second proximity sensors on the main body portion, and third and fourth proximity sensors on the stem portion.

In accordance with another embodiment, the proximity sensors include at least a first proximity sensor on the main body portion and at least a second proximity sensor on the stem portion, the ear bud includes an accelerometer, and control circuitry that is configured to analyze outputs from the first and second proximity sensors to determine whether the main body portion has been inserted into an ear and that is configured to use the accelerometer to determine whether the housing is moving.

In accordance with another embodiment, the control circuitry determines that the main body portion has been inserted to the ear when at least the first proximity sensor has a positive output indicating that the ear is adjacent to the first proximity sensor while at least the second sensor has a negative output indicating that no external object is adjacent to the second sensor.

In accordance with another embodiment, the first and second proximity sensors each have an infrared light-emitting diode that emits infrared light that passes through the housing and each have a light detector,.

Claim 1:
A wireless ear bud (<NUM>), comprising:
a housing (<NUM>) having a main body portion (<NUM>-<NUM>) and a stem portion (<NUM>-<NUM>) extending from the main body portion (<NUM>-<NUM>);
a speaker (<NUM>) in the main body portion (<NUM>-<NUM>);
a first proximity sensor (S1) in the main body portion (<NUM>-<NUM>) that produces a first sensor output;
a second proximity sensor (S3) in the stem portion (<NUM>-<NUM>) that produces a second sensor output;
a third proximity sensor (S2) in the main body portion (<NUM>-<NUM>) that produces a third sensor output;
a fourth proximity sensor (S4) in the stem portion (<NUM>-<NUM>) that produces a fourth sensor output and
control circuitry (<NUM>) that:
determines whether the ear bud (<NUM>) has been placed in a user's ear based on the first and third sensor outputs being positive and the second and fourth sensor outputs being negative; and
determines whether the ear bud (<NUM>) is being removed from the user's ear based on the first proximity sensor output being negative without using the second, third, and fourth proximity sensor (S3, S2, S4) outputs.