Abstract:
A system and method for controlling a telecommunications device capable of text telephone, and voice carry over or hearing carry over operation where transition from text to voice operation, and vice versa, is accomplished without operator intervention. The system includes a text telephone signal detector that detects the presence of text telephone signals and an audio control manager coupled to the text telephone signal detector. The audio control manager comprises an audio stream manger that controls the processing of audio signals, and an audio profile manager that controls the routing of voice signals to the audio peripherals and the audio peripheral output sound loudness.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to EPO Patent Application No. 07290483.2, filed on Apr. 19, 2007, incorporated herein by reference. 
     BACKGROUND 
     Teletypewriters allow the hearing or speech impaired to make unassisted telephone calls over the voice grade telephone system. Communicating with teletypewriters through the voice telephone system is called text telephony (“TTY”). There are hundreds of thousands of TTY users in the United States and many more worldwide. 
     A Telecommunications Relay Service (“TRS”) allows TTY users to communicate with voice telephone users. The TRS employs an operator called a Communication Assistant (“CA”) who serves as an interface between the TTY user and the voice telephone user. The CA voices the TTY messages to the voice telephone user, and types the voice telephone user&#39;s spoken responses for the TTY user. 
     Voice carry over (“VCO”) and hearing carry over (“HCO”) are two additional services offered by the TRS. These services allow the user to combine voice and TTY communication as he deems desirable. 
     VCO allows a hearing impaired user to communicate using his own voice while receiving typed responses. The CA translates the voice telephone user&#39;s spoken responses into text for the VCO user, while the voice telephone user hears the VCO user&#39;s spoken voice. 
     HCO allows a speech impaired person to type his input, while hearing the speech of the voice telephone user. The CA voices the VCO user&#39;s typed messages for the voice telephone user, while the HCO user directly hears the voice telephone user&#39;s speech. 
     Many modern TTY devices allow VCO or HCO operation in addition to standard all text operation. Unfortunately, these devices burden the user by requiring the user to manually select the TTY device&#39;s mode of operation by, for example, inputting a particular key sequence or toggling a dedicated switch. 
     SUMMARY 
     Accordingly there are herein disclosed apparatus, methods, and systems for dynamically and autonomously switching between TTY and voice operation in telecommunications devices. Some embodiments provide a method for configuring a telecommunications device including detecting text telephone signals to be processed by the telecommunications device and configuring, without user interaction, the telecommunications device to process the text telephone signals. 
     Some embodiments provide a system for processing voice and text telephone signals within a telecommunications device including a text telephone signal detector, and coupled to the text telephone signal detector, an audio control manager. The text telephone signal detector detects text telephone signals to be processed by the telecommunications device. The audio control manger configures the telecommunications device for text telephone signal processing when text telephone signals are detected by the text telephone signal detector. 
     Some embodiments provide a telecommunications device including a text telephone signal detector, an audio control manager, a transceiver for transmitting and receiving signals on a telecommunications network. The text telephone signal detector detects text telephone signals. The audio control manager is configured to adapt the telecommunications device for text telephone signal processing when text telephone signals are detected by the text telephone signal detector. 
     Notation and Nomenclature 
     Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” and “e.g.” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. The term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first component couples to a second component, that connection may be through a direct connection, or through an indirect connection via other components and connections. The term “system” refers to a collection of two or more hardware and/or software components, and may be used to refer to an electronic device or devices, or a sub-system thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following detailed description, reference will be made to the accompanying drawings, in which: 
         FIG. 1  shows an illustrative telecommunications system operating in voice carry over mode; 
         FIG. 2  shows a flow diagram for an illustrative TTY mode to voice mode control method; 
         FIG. 3  shows a block diagram of an illustrative system for controlling transitions from TTY operation to voice operation; 
         FIG. 4  shows an illustrative telecommunications device configured to allow transitions from TTY operation to voice operation without user intervention; 
         FIG. 5  shows an alternative illustrative telecommunications device configured to allow transitions from TTY operation to voice operation without user intervention; and 
         FIG. 6  show an illustrative text telephone coupled to a wireless telecommunications device configured to allow transitions from TTY operation to voice operation without user intervention. 
     
    
    
     The drawings show illustrative embodiments that will be described in detail. However, the description and accompanying drawings are not intended to limit the claimed invention to the illustrative embodiments, but to the contrary, the intention is to disclose and protect all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims. 
     DETAILED DESCRIPTION 
     Disclosed herein are various systems and methods for controlling audio processing in a telecommunications device capable of TTY operation, and VCO operation or HCO operation. The disclosed systems and methods include: 
     A method for controlling audio processing in a telecommunications device capable of TTY operation, and VCO operation or HCO operation; 
     A system for controlling audio processing in a telecommunications device capable of TTY operation, and VCO operation or HCO operation; and 
     Apparatus capable of transitioning from TTY operation to VCO operation or HCO operation with no user intervention. 
       FIG. 1  shows an illustrative telecommunications system for implementing VCO operation. Text telephone  101  is enabled for VCO operation. For purposes of illustration, text telephone  101  is depicted as a table top model, adapted for use on the wired telephone network, also known as Plain Old Telephone Service (“POTS”). In other embodiments text telephone  101  may be a wireless handset operable for TTY and VCO or HCO operation. Text telephone  101  includes keyboard  102  for use in non-VCO modes of operation. In VCO mode, keyboard  102  is not used to converse with the user of voice telephone  109 . To initiate a VCO call, the user of text telephone  101 , places a call to Relay Service (“TRS”)  107 . TRS  107 , in turn, calls voice telephone  109 . With these connections in place, the user of text telephone  101  voices conversation  105  into handset  104 . Voice transmission  113  is received by voice telephone  109  and converted into audible voice  112  by handset  110 . The user of telephone  109  voices replies  111  into handset  110 . Voice transmissions  108  from telephone  109  are intercepted by TRS  107 . TRS  107  converts the speech received from telephone  109  into text, and transmits the text  106  to text telephone  101 . Text transmission  106  is received by text telephone  101 , output on text telephone display  103 , and read by the text telephone user. 
     Operation in HCO mode is similar, but with the text telephone user typing input on keyboard  102  and hearing the voice telephone user&#39;s speech in handset  104  of text telephone  101 . The CA at TRS  107  intercepts the text telephone user&#39;s typed input and voices the words for the user of voice telephone  109  to hear. 
     TRS  107  enables a VCO or HCO user to communicate with voice telephone users. However when both parties to a tele-conversation employ VCO or HCO compatible telecommunications equipment TRS  107  may be omitted. The parties to the call may be directly connected through the telecommunications network, with each party employing voice or text communication as necessary. 
     With a conventional VCO or HCO enabled text telephone, the user employs the keyboard, or other manual control, to switch the text telephone from standard TTY operation to VCO or HCO operation. According to the present disclosure, text telephone  101  is operable for self-configuration for either voice or text operation without user intervention. When text telephone signals, for example Baudot, Cellular Text Telephone Modem (“CTM”), or other text representative signals received via a telecommunications network, attached keyboard, or other input device, are detected, the text telephone&#39;s audio processing circuitry is automatically configured for text reception; audio processing on the text channel may be disabled, and user audio is muted, (output volume reduced), to prevent the user from hearing the TTY tones. When not receiving text signals, the text telephone&#39;s audio processing circuitry is automatically configured for reception of voice signals (voice including any audio intended to be understood by the hearer); audio processing is enabled, user audio output volume is returned to a user preset level, and audio is routed to the appropriate interface, for example, the handset earpiece, speakerphone speaker, wired headset jack, or Bluetooth interface. 
     Text telephone signal detection is well known in the art and includes, for example, the text telephone signal detection methods described by ITU-T Recommendation V.18, entitled “Operational and internetworking requirements for DCEs operating in the text telephone mode” which is hereby incorporated by reference. 
       FIG. 2  shows a flow diagram of a method for controlling text telephone audio processing to automatically (i.e. without user interaction) enable VCO or HCO operation. Text telephone  101  is connected to telephone  109 , which may be either a voice or text telephone. The two telephones may be directly connected or connected through a TRS. Audio processing in text telephone  101  is configured for voice operation. In  202 , text telephone  101  receives signals that are transmitted through the telephone network. In  204 , text telephone  101  monitors the received signals to distinguish voice signals from TTY signals. If a TTY signal is detected, the voice stream is disabled (i.e. audio processing of the TTY signal is disabled) and TTY processing is enabled in  206 . For example, digital signal processor modules or other circuits that process the audio channel are instructed to discontinue audio processing. In  208 , the handset audio path is disabled; routing of audio signals within text telephone  101  is modified, preventing audio signals from driving the audio peripherals. The audio peripherals may include, for example, a handset speaker, a speakerphone speaker, a Bluetooth interface, or a headset jack. Audio parameters are set for text in  210 , audio is muted as there is no audio signal to be reproduced. As indicated in  212 , blocks  204 - 210  configure text telephone  101  for operation in TTY, VCO, or HCO mode, and the telephone continues to operate in TTY, VCO, or HCO mode while TTY signals are detected. 
     In  214 , text telephone  101  continues processing TTY signals and monitors the received signal for completion of the TTY signal sequence, indicating a resumption of voice signals. When the end of the TTY sequence is detected at  214 , for example by time-out from the last TTY signal detected, text telephone  101  discontinues TTY processing and reconfigures itself for voice processing. In  216 , the voice stream is enabled, for example by instructing a digital signal processor (“DSP”) or other circuits to resume audio processing. The appropriate voice audio path is reestablished in  218 , routing audio to the proper peripheral. In  220 , audio parameters are set for voice; audio volume is returned to a level appropriate for voice operation, for example, the level previously employed for voice operation. Text telephone  101  is now again configured for voice operation and remains so configured until a TTY signal is detected. 
     Although  FIG. 2  depicts control of audio processing, routing, and volume in a particular sequence, this depiction is a matter of convenience only. No particular sequence is intended, and modification of audio parameters may occur in any sequence or concurrently. Further, in at least some embodiments, all of the actions depicted in  FIG. 2  are performed without user interaction. 
     The above description of text telephone operation is directed to the perspective of signal received via the telephone network. However, a telecommunications device adapted to voice and TTY use, including VCO or HCO modes, comprises two audio channels, one detecting and processing text or audio input by the user, and the other detecting and processing text or audio received via the telephone network. These channels operate independently, and detection of text on one channel and the attendant configuration of that channel has no effect on the operation of the other channel. Each channel is dynamically and independently configured for voice or text processing without user intervention to enable VCO or HCO operation. 
       FIG. 3  shows a block diagram of an illustrative system for controlling text and audio processing in a telecommunications device adapted for TTY, and VCO or HCO operation. Text/audio signal  301  is input to TTY detector  302  and to signal processor  309 . TTY detector  302  monitors text/audio signal  301  to determine whether the signal is a TTY or other text signal, or an audio signal. TTY detector  302  outputs signal  303  to Audio Control Manager  305 . Signal  303  indicates to Audio Control Manager  305  whether text or audio signals are being received, enabling Audio Control Manager  305  to configure the telecommunication device&#39;s audio systems to handle the signal appropriately. Audio Control Manager  305  comprises two sub-components, Audio Stream Manager  306 , and Audio Profile Manager  304 . 
     Audio Stream Manager  306  controls processing of text/audio signal  301  by audio signal processor  309 . If signal  303  indicates to Audio Stream Manager  306  that text/audio signal  301  is a text signal, then Audio Stream Manager  306  outputs signal  307  instructing audio signal processor  309  to disable audio processing and to initiate text processing. When signal  303  indicates that the text sequence is complete, and that signal  301  comprises audio, Audio Stream Manager  305  outputs signal  307  instructing audio signal processor  309  to enable audio processing and to discontinue text processing. 
     Audio Profile Manager  304  controls the various audio device entities  310  included in a telecommunications device. Included in such control is routing of audio signal (not shown) from signal processor  309  to the selected audio entity  310 , and selection of the audio output volume level for each audio entity  310 . The audio device entities  310  encompass the telephone&#39;s various audio peripherals. Each included entity may require different signal routing and volume parameters. Examples of various audio entities include, but are not limited to, handset audio entity, speakerphone audio entity, headset audio entity, and Bluetooth audio entity. When signal  303  indicates to Audio Profile Manager  304  that text/audio signal  301  is a text signal, then Audio Profile Manager  304  outputs signal  308  disabling audio signal routing to the audio peripherals and muting audio. When signal  303  indicates that the text sequence is complete, and signal  301  comprises audio, Audio Profile Manager  304  outputs signal  308  routing audio to the appropriate audio peripheral, and increasing audio volume to a level suitable for that peripheral, for example, the volume level last applied to that peripheral or a default volume known to be safe. 
     Because a telecommunications device typically includes a pair of audio channels, a telecommunications device enabled to automatically and independently configure each channel for TTY or audio processing may employ a separate instance of the Audio Control Manager  305  for each channel. Alternatively, multiple channels may share a single instance of the Audio Control Manager  305 . However implemented, input and output channels are autonomously and independently controlled to switch from TTY to voice operation without user interaction. For example, a TTY keyboard generating Baudot signals may be interfaced to a telephone incorporating the above described system through a microphone or headset connector on the telephone. The TTY signals generated by the keyboard are recognized by TTY detector  302 , and consequently Audio Control Manager  305  initiates TTY processing and adjusts input volume to an optimum level for Baudot input. Simultaneously, an audio signal may be received via the telecommunications network and detected by TTY detector  302 . Audio Control Manager  305  initiates audio processing on this channel, routes the audio to a selected audio peripheral, and adjusts output volume to an appropriate level. Thus, independent and autonomous TTY signal detection and audio channel control enables VCO or HCO operation without user configuration. 
     TTY detector  302  and Audio Control Manager  305  may be implemented in numerous forms, for example, programs executing on a DSP, microcontroller, or microprocessor, or as dedicated circuitry, either integrated or discrete. 
       FIG. 4  shows an illustrative embodiment of a telecommunications device, a teletypewriter,  401  adapted to dynamically switch between TTY mode and VCO or HCO mode without operator intervention in accordance with the present disclosure. Teletypewriter  401  includes keyboard  404  for text entry in TTY or HCO modes, and display  403  for output of text in TTY or VCO modes. Handset  402  is applicable to both VCO and HCO modes, as are speaker  405  and microphone  409 . Teletypewriter  401  comprises TTY detector  302  for detection of TTY and audio signals, Audio Stream Manager  306  to control processing of audio and TTY signals, and Audio Profile Manager  304  to control audio signal routing to audio peripherals and audio peripheral operational parameters, such as audio volume. Transceiver  406  is provided for transmitting and receiving signals on a wired or wireless telecommunications network. 
       FIG. 5  shows an embodiment of a wireless telecommunications device  501  adapted to dynamically switch between TTY mode, and VCO or HCO mode without operator intervention. Wireless telecommunications device  501  includes keyboard  503  for text entry in TTY or VCO modes, and display  502  for presentation of text in TTY or VCO modes. Other embodiments, for example, an embodiment implemented in a conventional cellular telephone may employ the cellular telephone keypad rather than the illustrated keyboard. Wireless telecommunications device  501  may also include a speaker and microphone (not shown) to facilitate HCO and VCO operation. Peripheral expansion ports  507  may be included to allow connection of external peripherals to facilitate TTY, and VCO or HCO operation. Keyboard  504  and headset  505  are illustrative examples. Although wired peripheral connections are illustrated, it is understood that peripherals may be connected by wireless means, for example, infrared or Bluetooth interfaces. Wireless telecommunications device  501  comprises TTY detector  302  for detection of TTY signals, coupled to both Audio Stream Manager  306  for control of audio and text signal processing, and Audio Profile Manager  304  for control of audio signal routing to audio peripherals and audio peripheral operational parameters, such as audio volume. Transceiver  506  is provided for transmitting and receiving signals on a wireless telecommunications network. 
       FIG. 6  shows an illustrative TTY compatible wireless telecommunications device  616  configured to switch from TTY operation to voice operation without user intervention coupled to a text telephone  602 . In the illustration of  FIG. 6 , telecommunications device  616  is exemplified as a cellular telephone, and text telephone  602  is shown as a portable device suitable for convenient transport. Text telephone  602  comprises keyboard  606 , for entry of text in TTY or HCO modes, and display  604  for output of text in TTY or VCO modes. Text telephone  602  is coupled to cellular telephone  616  by interconnect cable  614 , which connects to text telephone interface port  608  and headset port (or other interface port)  620  on cellular telephone  616 . Although physical interconnect cable  614  is illustrated, it is understood that the available interconnection means includes wireless interconnection, such as Bluetooth, infrared, or other wireless interfaces. Cellular telephone  616  comprises TTY detector  302  for detection of TTY signals, coupled to both Audio Stream Manager  306  for control of audio and text signal processing, and Audio Profile Manager  304  for control of audio signal routing to audio peripherals and audio peripheral operational parameters, such as audio volume. Transceiver  624  is provided for transmitting and receiving signals on a wireless telecommunications network. Cellular telephone  616  additionally comprises microphone  618  for VCO use and speaker  622  for HCO operation. Audio input or output may also be performed using an external headset, integrated speakerphone speaker, etc. 
     As disclosed, TTY detector  302  identifies TTY signals received either via the telecommunications network or from text telephone  602 . Based on the presence or absence of a TTY signal, Audio Stream Manager  306  and Audio Profile Manager  304  control audio processing, and audio device entities to simplify VCO or HCO operation. In the system of  FIG. 6 , cellular telephone  616  supplies the audio functionality required for VCO or HCO operation, and text telephone  602  supplies text entry and display. No user action is required to switch between TTY, VCO, and HCO operation. 
     In an alternative embodiment of the system of  FIG. 6 , text telephone  602  includes a TTY detector, Audio Stream Manager, and Audio Profile Manger. Audio transducers (speaker and microphone) included in text telephone  602 , or an external headset (not shown) coupled to text telephone  602 , perform audio input or output for VCO or HCO operation. Text telephone  602  is self-configured for TTY, VCO, or HCO operation based on the detection of TTY signals. In this alternative embodiment, microphone  618  and speaker  622  of cellular telephone  616  need not be used for VCO or HCO operation. Text telephone  602  provides the user with audio and TTY functionality, including automated switching between audio and TTY as disclosed herein, while cellular telephone  616  provides network access. 
     While illustrative embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are illustrative and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.