Ambience-adapted audio watermarking for teleconferencing

An apparatus comprising:

• a loudspeaker to play a loudspeaker signal into a space;
• a microphone to detect audio in the space, to produce a feedback audio signal;
• and
• a controller coupled to the loudspeaker and the microphone and configured to perform:
• estimating acoustic parameters for the space including a reverberation time and an ambient noise power based on the feedback audio signal and the loudspeaker signal;
• receiving an incoming audio signal that is not detected by the microphone;
• using the acoustic parameters, generating an acoustic watermark signal that, when played into the space through the loudspeaker, would be inaudible to a listener;
• adding the acoustic watermark signal to the incoming audio signal to produce a watermarked audio signal;
• and
• causing the watermarked audio signal to be played by the loudspeaker into the space.

A non-transitory computer readable medium encoded with instructions that, when executed by a processor of an endpoint device including a loudspeaker and a microphone, cause the processor to perform:

• causing the loudspeaker to play a loudspeaker signal into a space;
• receiving, from the microphone, audio detected in the space as a feedback audio signal;
• estimating acoustic parameters for the space including a reverberation time and an ambient noise power based on the feedback audio signal and the loudspeaker signal;
• receiving an incoming audio signal that is not detected by the microphone;
• using the acoustic parameters, generating an acoustic watermark signal that, when played into the space through the loudspeaker, would be inaudible to a listener;
• adding the acoustic watermark signal to the incoming audio signal to produce a watermarked audio signal;
• and
• causing the watermarked audio signal to be played by the loudspeaker into the space.