Method and device for operating a microphone system, especially in a motor vehicle

• US 6,748,088 B1
• Filed: 11/20/2000
• Issued: 06/08/2004
• Est. Priority Date: 03/23/1998
• Status: Expired due to Term

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Schaaf, Klaus
• Primary Examiner(s): Harvey, Minsun Oh
• Assistant Examiner(s): Grier, Laura A.
• Application Number:
  US09/646,826
• Time in Patent Office: 1,296 Days
• Field of Search: 381/92, 381/91, 381/110, 381/86, 280/735, 367/118-127
• US Class Current: 381/92
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A device for operating a microphone system, particularly in a motor vehicle, detects speech sound in several different physical locations to track a virtual microphone location, which is optimized in relation to a moving speech source. From the evaluation of variables, such as operating time, phase and/or amplitude, the individual microphone locations are virtually weighted, and the audio signals from the microphones are added or otherwise combined.

Claims

1. A method for operating a microphone system, comprising the steps of:

(a) detecting a sound at a plurality of spatially distributed locations;

(b) simultaneously evaluating at least one variable of the sound detected by each of the microphones;

(c) weighting the locations of the microphones and combining audio signals from the microphones based on the evaluating step (b);

(d) tracking a changed location in 3-dimensional space of a source of the sound based on a directivity of the microphone system by shifting at least one of the variables of the microphone signals;

(e) optimizing in 3-dimensional space a virtual microphone location in relation to the position in 3-dimensional space of a movable sound source;

(f) feeding the signals from the microphones to a transmission device after the evaluating step (b).

2. The method according to claim 1, wherein the at least one variable includes at least one of a propagation delay, a phase and an amplitude.

3. The method according to claim 1, further comprising the step of analyzing the microphone signals by evaluating a sound propagation time of each microphone.

4. The method according to claim 1, wherein the spatially distributed locations are non-coplanar.

5. The method according to claim 1, further comprising the step of arranging the plurality of spatially distributed locations in a motor vehicle.

6. The method according to claim 1, further comprising the step of providing a microphone at each of the spatially distributed locations.

7. A method for operating a microphone system, comprising the steps of:

(a) detecting a sound at a plurality of spatially distributed locations;

(b) simultaneously evaluating at least one variable of the sound detected by each of the microphones;

(c) weighting the locations of the microphones and combining audio signals from the microphones based on the evaluating step (b);

(d) tracking a changed location in 3-dimensional space of a source of the sound based on a directivity of the microphone system by shifting at least one of the variables of the microphone signals;

(e) optimizing in 3-dimensional space a virtual microphone location in relation to the position in 3-dimensional space of a movable sound source;

(f) feeding the signals from the microphones to a transmission device after the evaluating step (b);

wherein the microphone system is provided in a motor vehicle.

8. The method according to claim 7, further comprising the steps of:

determining a position of the sound source based on the at least one variable; and

determining whether to trigger at least one safety system of the motor vehicle in accordance with the determined sound source position.

9. The method according to claim 8, wherein the safety system includes an air bag system.

10. A device for operating a microphone system, the microphone system including at least two spatially distributed microphones, sound signals being feedable by the microphone system into at least one of an audio system, a telephone system, a voice-controlled input unit and an active noise compensation system, the device comprising:

a signal analyzer configured to combine the signals from each of the microphones;

an arrangement including a microphone-location-determination unit logically and bidirectionally connected to the signal analyzer, the microphone-location-determination unit configured to ascertain a virtual microphone location in 3-dimensional space and to transmit a return signal to the signal analyzer to perform at least one of controlling and selecting one of an optimum microphone in 3-dimensional space relative to the sound source and a directivity characteristic of the microphone system.

11. The device according to claim 10, wherein the arrangement further includes a calculation unit.

12. The device according to claim 11, wherein the calculation unit is configured to determine a position of the sound source and to transmit a blocking signal to at least one safety system of a motor vehicle in accordance with an evaluation of the position.

13. The device according to claim 12, wherein the safety system includes at least one of an air bag system and a seat-belt tensioner.

14. The device according to claim 11, wherein the microphone-location-determination unit is configured to determine the virtual microphone location in accordance with a simultaneous evaluation of each of the microphone signals to thereby track a movable position of the sound source.

15. The device according to claim 10, further comprising:

at least two adjustable amplifiers, each of the adjustable amplifiers being connected to an output of a respective one of the microphones;

an evaluating device configured to adjust the amplifiers;

an adder, an output of each amplifier being wired to the adder; and

a transmitter configured to transmit audio signals, the adder being connected to the transmitter;

wherein the output of each amplifier is connected to the evaluating device in parallel with the adder to thereby define an information feedback loop.

16. The device according to claim 10, wherein the microphone system is provided in a motor vehicle.

17. The device according to claim 10, wherein the spatially distributed microphones are non-coplanar.