Communication system for multiple acoustic zones
An In-Car Communication (ICC) system supports the communication paths within a car by receiving the speech signals of a speaking passenger and playing it back for one or more listening passengers. Signal processing tasks are split into a microphone related part and into a loudspeaker related part. A sound processing system suitable for use in a vehicle having multiple acoustic zones includes a plurality of microphone In-Car Communication (Mic-ICC) instances coupled and a plurality of loudspeaker In-Car Communication (Ls-ICC) instances. The system further includes a dynamic audio routing matrix with a controller and coupled to the Mic-ICC instances, a mixer coupled to the plurality of Mic-ICC instances and a distributor coupled to the Ls-ICC instances.
1. An apparatus comprising
microphone instances to receive audio signals from corresponding microphones,
loudspeaker instances to generate signals for corresponding loudspeakers, and
a routing matrix to provide signal paths from at least one of the microphone instances to at least two of the loudspeaker instances,
wherein each of said microphones is configured to receive sound from a corresponding acoustic zone from a plurality of acoustic zones,
wherein each of said loudspeakers is configured to transmit sound into a corresponding one of said acoustic zones; and
wherein said routing matrix is configured to inactivate a loudspeaker instance for an acoustic zone that corresponds to an active microphone instance and, for each path from an active microphone to an active loudspeaker, to determine an equalizer setting for said path,
wherein the number of equalizer settings is one less than the number of loudspeakers.
2. The apparatus of claim 1 , wherein said microphone instances are configured to compensate for varying speech levels by performing perform high-pass filtering noise reduction, and gain control.
3. The apparatus of claim 1 , wherein said routing matrix comprises an adaptive gain controller that adjusts playback level to compensate for current noise levels by adjusting a playback level for each loudspeaker instance individually to compensate for current noise levels within a corresponding one of said acoustic zones.
4. The apparatus of claim 1 , wherein a number of said microphone instances equals a number of said loudspeaker instances.
5. The apparatus of claim 1 , further comprising, for each of said microphone instances, forming a specific subset of said loudspeaker instances.
6. The apparatus of claim 1 , further comprising a notch filter, said notch filter being a constituent of said routing matrix.
7. The apparatus of claim 1 , wherein said routing matrix comprises at most one notch filter.
8. The apparatus of claim 1 , wherein vehicle speed is used to determine said equalizer settings.
9. The apparatus of claim 1 , wherein the acoustic zones are formed within a vehicle.
10. The apparatus of claim 1 , wherein said routing matrix comprises a mixer coupled to said microphone instances, a distributor coupled to said loudspeaker instances, and a controller coupled to said distributor and to said mixer, wherein said controller comprises an adaptive gain controller.
11. The apparatus of claim 1 , wherein said routing matrix comprises a controller that obtains signal information from said microphone instances and, based on said signal information, determines said active microphone instance.
12. The apparatus of claim 1 , wherein said loudspeaker instances are configured to carry out gain compensation to compensate for current noise levels in a corresponding one of said acoustic zones.
13. The apparatus of claim 1 , wherein said routing matrix comprises a controller that is configured to set weights to be applied to each of said loudspeaker instances, wherein, for each loudspeaker instance, said weight depends on a level of background noise in a corresponding acoustic zone for said loudspeaker.
14. The apparatus of claim 1 , wherein at least one of said microphone instances processes more then one microphone signal and wherein at least one of said loudspeaker instances addresses more than one loudspeaker.
15. The apparatus of claim 1 , wherein among said microphone instances is a microphone instance that receives microphone signals from plural microphones and carries out beamforming based at least in part on said signals.
16. The apparatus of claim 1 , wherein said routing matrix is configured to pass a signal from a microphone instance that serves a first zone to a plurality of acoustic zones other than said first zone.
17. The apparatus of claim 1 , wherein said acoustic zones comprise a driver zone, a front-passenger zone, and plural back-seat zones and wherein said router is configured to pass speech uttered by a driver in said driver zone to said back-seat zones and to exclude said front-passenger zone.
18. The apparatus of claim 1 , wherein said routing matrix, which is configured to pass a signal from a first microphone instance to a first loudspeaker instance is configurable to pass said signal from said first microphone instance to a second loudspeaker instance.
19. The apparatus of claim 1 , wherein said routing matrix is a dynamic routing matrix that comprises a notch filter that receives signals from all of said microphone instances, said notch filter being coupled to all of said loudspeaker instances.
20. A method, comprising:
receiving audio signals from a plurality of microphones at a corresponding one of a plurality of microphone instances, wherein each of the microphones is configured to receive sound from a corresponding one of a plurality of acoustic zones, wherein a number of the acoustic zones is at least three;
generating signals, by a plurality of loudspeaker instances, for corresponding ones of loudspeakers, each of which is configured to transmit sound into a corresponding one of the plurality of acoustic zones;
routing of signal paths from at least one of the microphone instances to at least two of the loudspeaker instances by determining an active one of the microphone instances corresponding to an acoustic zone of an active speaker; and
determining an equalizer setting from each path from each active one of the microphones to each active one of the loudspeakers such that a number of equalizer settings is one less than a number of loudspeakers.