摘要:
A variable voice compression device and method in a voice messaging system is provided. The device includes a call related information/coding table or database which contains associations between call related information regarding desired calling parties, and selected coding techniques and effective data rates resulting in varying voice compression ratios. Upon receipt of an incoming call, call related information sent from the central office is compared to entries in the call related information/coding table or database. If a match is found, the subsequent voice message is encoded with a coding technique and effective data rate determined from the matching entry in the call related information/coding table or database. Otherwise, the voice message is encoded with a default coding technique and effective data rate.
摘要:
An adjunct Type II caller ID/call waiting (CIDCW) receiver unit is provided which has a greatly improved ability to detect tones and other call related information on a telephone line from a central office while the customer premises equipment is in an off-hook condition. The inventive adjunct CIDCW receiver unit is placed in series between the telephone line from the central office and the customer premises equipment, rather than in parallel with the customer premises equipment as in conventional adjunct CIDCW receiver units. A second telephone line interface (TLI) is included in the adjunct CIDCW receiver unit for connection to the customer premises unit to simulate the impedance of the telephone line. The adjunct CIDCW receiver unit has the ability to disconnect, mute or suppress the microphone signal from the customer premises equipment from being included in the signal received by the call related information receiver portion of the adjunct CIDCW receiver unit.
摘要:
Type 2 caller ID/call waiting (CIDCW) customer premises equipment (CPE) is provided which has a greatly improved method of detecting tones indicating the availability of call information regarding an incoming call while the customer premises equipment is in an off-hook condition. A hybrid echo canceler (HEC) algorithm is added to the customer premises equipment (CPE) to suppress the signal from the microphone of the customer premises equipment from being included in the signal analyzed for the presence of tones. Thus, the microphone of the customer premises equipment need not be muted upon detection of the alerting CAS tone sequence in a Caller ID service. The HEC algorithm runs substantially continuously in a preferred embodiment, and may be combined with a conventionally operating HEC which cancels reflections due to the hybrid or telephone line interface.
摘要:
A digital telephone answering device having speakerphone capability allows a recorded message to be played back and heard by the far-end party as well as over the local speakerphone by the near-end party during speakerphone operation as if it were a normal receive signal. Moreover, normal speakerphone conversation is possible during this conversational playback mode allowing the far-end party and/or near-end party to break-in over the played back pre-recorded message as desired and be heard by the other party. Both message and conversation signals are preferably (but not necessarily) at similar levels. Also, the message playback at the near end is preferably (but not necessarily) subject to the same speakerphone digital volume control as that received at the far end.
摘要:
An automotive system provides an integrated user interface for control and communication functions in an automobile or other type of vehicle. The user interface supports voice enabled interactions, as well as other modes of interaction, such as manual interactions using controls such as dashboard or steering wheel mounted controls. The system also includes interfaces to devices in the vehicle, such as wireless interfaces to mobile devices that are brought into the vehicle. The system also provides interfaces to information sources such as a remote server, for example, for accessing information.
摘要:
Methods and apparatuses for deriving a signal-to-noise ratio based at least in part on a measured level of a signal carrying far-end speech, and a measured level of a signal carrying ambient acoustic noise; determining a target gain adjustment based at least in part on the derived signal-to-noise ratio; applying the target gain adjustment to the signal carrying far-end speech to produce a gain-adjusted signal; and providing the gain-adjusted signal for audio output from a communications device.
摘要:
A system for combining signals includes a first microphone generating a first input signal having a first voice component and a first noise component, a second microphone generating a second input signal having a second voice component and a second noise component, a mixing circuit, and an adaptive filter. The mixing circuit applies a first gain having a value α to the first input signal to produce a first scaled signal, applies a second gain having a value 1−α to the second input signal to produce a second scaled signal, and sums the first scaled signal and the second scaled signal to produce a summed signal. The adaptive filter computes an updated value of α to minimize the energy of the summed signal based on the summed signal, the first input signal and the second input signal, and provides the updated value of α to the mixing circuit.
摘要:
A microphone includes a sensing element having two opposing sides; and a housing including a first acoustic port having an external-facing portion defined in part by a first aperture located on a first housing side and an internal-facing portion defined in part by a first cavity within the housing, the first cavity being coupled to a first side of the element; and a second acoustic port having an external-facing portion defined in part by a second aperture located on the first housing side and an internal-facing portion defined in part by a second cavity within the housing, the second cavity being coupled to a second side of the element. The ports are spaced apart at a distance such that a level of an electrical response by the element to an ambient acoustic noise at 50 dB A-weighted sound pressure level exceeds an internal electrical noise level of the element.
摘要:
An echo canceller system includes first and second echo cancellers. Each echo canceller includes a foreground filter and an adaptive background filter, with the foreground filter providing the actual echo cancellation and the background filter updating the foreground filter. The echo canceller system also includes send and receive paths, a shared coefficient memory, and a controller for switching the shared coefficient memory between background filters in response to signals along the send and receive paths. The switching includes resetting the shared coefficient memory to prevent any transfer of filter coefficients between the background filters. The background filters operate one at a time, depending on which background filter has access to the shared coefficient memory, while the foreground filters operate simultaneously. The echo canceller system is well-suited for use in loudspeaking telephone sets, with the first echo canceller canceling a line echo through a hybrid transformer, and the second echo canceller canceling an acoustic echo between a loudspeaker and a microphone. The coefficient memory may be switched to the first background filter in response to a near-end signal without a far-end signal (i.e., transmit state), and switched to the second background filter in response to a far-end signal without a near-end signal (i.e., receive state).
摘要:
A system for combining signals includes a first microphone generating a first input signal having a first voice component and a first noise component, a second microphone generating a second input signal having a second voice component and a second noise component, a mixing circuit, and an adaptive filter. The mixing circuit applies a first gain having a value α to the first input signal to produce a first scaled signal, applies a second gain having a value 1−α to the second input signal to produce a second scaled signal, and sums the first scaled signal and the second scaled signal to produce a summed signal. The adaptive filter computes an updated value of α to minimize the energy of the summed signal based on the summed signal, the first input signal and the second input signal, and provides the updated value of α to the mixing circuit.