Method and apparatus for active reduction of speakerphone singing
AssigneeAT&T Intellectual Property II, L.P.
InventorsRichard Henry Erving, Robert Raymond Miller, II
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Abstract
In a speakerphone device identification of signals (i.e., voice input or speaker output) in a process for reducing acoustic feedback, in a communication device, is accomplished by adding a signature noise (i.e., an identification mark) to output signals radiated by the speaker to enable these signals to be separated from speech input to the microphone. Having identified the signal (i.e., speech output) likely to cause a “singing” phenomenon, appropriate insertion loss to reduce the feedback may be added to the appropriate speech path within the communication device, to reduce a probability of singing.
Claims17
A method of reducing feedback in a communication device having a microphone and a speaker, the communication device being connected to a network;
- the method comprising:
- applying an identification mark to output from the speaker;
- correlating the identification mark with a signal from the microphone to produce a correlation signal reflective of an amount of feedback;
- introducing insertion loss in the microphone and speaker based on the correlation signal and relative signal levels of the microphone and speaker, in order to reduce the feedback.
A speakerphone connected to a communication network, comprising:
- a loudspeaker for providing voice output from an output path;
- a microphone for accepting voice input to an input path;
- a signal identification mark generator connected to modulate a voice output signal with a signal identification mark;
- a correlator connected to both the signal identification mark generator and the input path to produce a correlation signal reflective of an amount of feedback;
- and
- a loss control processor to insert loss in the input and output paths responsive the correlation signal, to reduce signal feedback between the input and output path.
Dependencies are inferred from the claim text.