Multi-channel communication system

• US 5,602,928 A
• Filed: 01/05/1995
• Issued: 02/11/1997
• Est. Priority Date: 01/05/1995
• Status: Expired due to Term

• Current Assignee: Digisonix Incorporated
• Original Assignee: Digisonix Incorporated
• Inventors: Bremigan, Cary D., Eriksson, Larry J.
• Primary Examiner(s): Isen, Forester W.
• Application Number:
  US08/368,920
• Time in Patent Office: 768 Days
• Field of Search: 381/71, 381/94
• US Class Current: 381/71.4
• CPC Class Codes: G10K 11/17817 between the output signals and the error signals, i.e. secondary path
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17881 the reference signal being an acoustic signal, e.g. recorded with a microphone
• CPC Class Codes: G10K 11/17883 the reference signal being derived from a machine operating condition, e.g. engine RPM or vehicle speed
• CPC Class Codes: G10K 11/17885 additionally using a desired external signal, e.g. pass-through audio such as music or speech
• CPC Class Codes: G10K 2210/108 Communication systems, e.g. where useful sound is kept and noise is cancelled
• CPC Class Codes: G10K 2210/128 Vehicles
• CPC Class Codes: G10K 2210/3012 Algorithms
• CPC Class Codes: G10K 2210/3019 Cross-terms between multiple in's and out's
• CPC Class Codes: G10K 2210/3027 Feedforward
• CPC Class Codes: G10K 2210/3042 Parallel processing
• CPC Class Codes: G10K 2210/505 Echo cancellation, e.g. multipath-, ghost- or reverberation-cancellation

Abstract

A multi-channel communication system is provided. In an active acoustic attenuation implementation, noise, including cross-coupled noise between channels and locations, designated audio signals, and echoes, are canceled, but not speech from another location. A particularly desirable vehicle application is provided.

Claims

1. A communication system comprising:

a plurality of zones subject to noise from one or more noise sources;

one or more speaking locations in each zone such that a person at a speaking location is subject to noise from a noise source;

a plurality of speakers, each introducing sound into a respective zone at a respective speaking location;

a plurality of microphones each sensing noise and speech at a respective speaking location;

a plurality of adaptive filter models each canceling noise from a respective noise source, each model having a model input from a reference signal correlated to said noise from said respective noise source, each model having a plurality of error inputs, each model having an output outputting a correction signal to cancel noise from the respective noise source, such that the output of the microphone carries a speech signal from a person at the speaking location but not a noise signal from the noise source;

the output of at least one microphone carrying the speech of a first person at one speaking location being supplied to at least one speaker at another speaking location, such that a second person at said other speaking location can hear the speech of said first person at said one speaking location.

2. The invention according to claim 1 comprising a first set of a plurality of adaptive filter models each acoustically canceling noise, and a second set of a plurality of adaptive filter models each electrically canceling noise.

3. The invention according to claim 2 wherein said first set of models includes modeling of at least one of a respective said speaker and the respective path between the speaker and a respective microphone, and wherein said second set of models are operated at a substantially higher sampling rate than said first set of models.

4. The invention according to claim 1 wherein at least one of said models has a model input from a summer summing said noise with a designated audio signal.

5. The invention according to claim 1 wherein at least one of said zones is in a vehicle having an occupant restraint system including a shoulder harness, and wherein at least one of said microphones is mounted to said shoulder harness.

6. The invention according to claim 1 wherein each of said zones is in a vehicle.

7. The invention according to claim 6 wherein all of said zones are in the same vehicle.

8. The invention according to claim 1 wherein at least one of said zones is in a vehicle, and at least another of said zones is external to said vehicle.

9. An active acoustic attenuation system comprising:

a plurality of zones subject to noise from one or more noise sources;

one or more speaking locations in each zone such that a person at a speaking location is subject to noise from a noise source;

a plurality of speakers, each introducing sound into a respective zone at a respective speaking location;

a plurality of error microphones each sensing noise and speech at a respective speaking location;

a plurality of adaptive filter models each canceling noise from a respective noise source at a respective speaking location as sensed by a respective error microphone, each model having a model input from a reference signal correlated to said noise from said respective noise source, each model having a plurality of error inputs from respective error microphones, each model having an output outputting a correction signal to introduce canceling sound at the respective speaking location to cancel noise from the respective noise source, such that the output of the error microphone carries a speech signal from a person at the speaking location but not a noise signal from the noise source;

the output of at least one error microphone carrying the speech of a first person at one speaking location being supplied to at least one speaker at another speaking location, such that a second person at said other speaking location can hear the speech of said first person at said one speaking location.

10. The invention according to claim 9 wherein each said model has an error input from each of said error microphones.

11. The invention according to claim 9 comprising:

a first said zone comprising first and second speaking locations;

a second said zone comprising third and fourth speaking locations;

a first said speaker at said first speaking location;

a second said speaker at said second speaking location;

a third said speaker at said third speaking location;

a fourth said speaker at said fourth speaking location;

a first said error microphone at said first speaking location;

a second said error microphone at said second speaking location;

a third said error microphone at said third speaking location;

a fourth said error microphone at said fourth speaking location;

a first said model having a model output to said first speaker, and first, second, third and fourth error inputs from said first, second, third and fourth error microphones, respective;

a second said model having a model output to said second speaker, and first, second, third and fourth error inputs from said first, second, third and fourth error microphones, respective;

a third said model having a model output to said third speaker, and first, second, third and fourth error inputs from said first, second, third and fourth error microphones, respective;

a fourth said model having a model output to said fourth speaker, and first, second, third and fourth error inputs from said first, second, third and fourth error microphones, respective.

12. The invention according to claim 11 wherein said first and second zones are subject to noise from a common noise source, and each of said first, second, third and fourth models has a model input receiving a common reference signal correlated to noise from said common noise source.

13. The invention according to claim 11 comprising:

a fifth adaptive filter model;

a sixth adaptive filter model;

a seventh adaptive filter model;

an eighth adaptive filter model;

a first summer having an input from said first model, and an output supplied to said first speaker;

a second summer having an input from said second model, and an output supplied to said second speaker;

a third summer having an input from said third model, and an output supplied to said third speaker;

a fourth summer having an input from said fourth model, and an output supplied to said fourth speaker;

a fifth summer having an input from said fifth model;

a sixth summer having an input from said sixth model;

a seventh summer having an input from said seventh model;

an eighth summer having an input from said eighth model;

a ninth summer having an input from said first error microphone and another input from said second microphone, and having an output supplied to said fifth summer;

a tenth summer having an input from said third error microphone and another input from said fourth error microphone, and having an output supplied to said sixth summer;

said fifth summer having an output supplied to said seventh summer and to an error input of said fifth model;

said sixth summer having an output supplied to said eighth summer and to an error input of said sixth model;

said seventh summer having an output supplied to said third and fourth summers and to a model input of said eighth model and to an error input of said seventh model;

said eighth summer having an output supplied to said first and second summers and to a model input of said seventh model and to an error input of said eighth model.

14. The invention according to claim 13 wherein each said first and second zones are subject to noise from a common noise source, and each of said first, second, third, fourth, fifth and sixth models has a model input receiving a common reference signal correlated to noise from said common noise source.

15. The invention according to claim 14 comprising an eleventh summer having an input from said common reference signal and another input from a designated audio signal, and having an output supplied to said model inputs of said fifth and sixth models.

16. The invention according to claim 9 comprising a first set of a plurality of adaptive filter models each acoustically canceling noise, and a second set of a plurality of adaptive filter models each electrically canceling noise.

17. The invention according to claim 16 wherein at least one model of said second set has a model input from a summer summing said noise with a designated audio signal to cancel said designated audio signal at the respective speaking location.

18. The invention according to claim 16 wherein said first set of models includes modeling of at least one of a respective said speaker and the respective error path between the speaker and a respective said error microphone, and wherein said second set of models are operated at a substantially higher sampling rate than said first set of models.

19. The invention according to claim 9 wherein at least one of said zones is in a vehicle having an occupant restraint system including a shoulder harness, and wherein at least one of said error microphones is mounted to said shoulder harness.

20. The invention according to claim 9 comprising a further plurality of adaptive filter models each canceling speech of a person in one zone from the signal sent to a speaker in said one zone from an error microphone in another zone.

21. The invention according to claim 9 wherein each of said zones is in a vehicle.

22. The invention according to claim 21 wherein all of said zones are in the same vehicle.

23. The invention according to claim 9 wherein at least one of said zones is in a vehicle, and at least another of said zones is external to said vehicle.

24. An occupant restraint system for a vehicle, comprising a shoulder harness including a belt, and a communication system microphone mounted to said belt such that said microphone is automatically positioned in proper location upon deployment of said belt, and a wire running from said microphone and connected to a seat belt interlock to provide feedback information confirming deployment of said belt and presence of an occupant in the respective location.