Process and device for compensating for signal loss

• US 6,980,663 B1
• Filed: 08/15/2000
• Issued: 12/27/2005
• Est. Priority Date: 08/16/1999
• Status: Expired due to Fees

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Linhard, Klaus
• Primary Examiner(s): Pendleton, Brian T.
• Application Number:
  US09/638,499
• Time in Patent Office: 1,960 Days
• Field of Search: 381/86, 381/83, 381/93, 381 711- 7112
• US Class Current: 381/86
• CPC Class Codes: B60R 11/0217 for loud-speakers
• CPC Class Codes: B60R 11/0247 for microphones or earphones
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 3/02 for preventing acoustic reaction , i.e. acoustic oscillatory feedback specially adapted for hearing aids H04R25/453

Abstract

For an especially low loss and echo free communication between several participants in a room (1) an inventive process for the compensation of losses of a signal(S) along a transmission path between at least one transmission point (6) and one receiving point (4) in a room (1) determining the transmission path of signal (S) and via the transmission paths at least one parameter of an associated transmission function will be determined, whereby via the determined parameters the signal level for a given position (P1 through P4) on the transmission path is controlled. Additionally an especially suitable device is provided for the implementation of the process.

Claims

1. A process for the compensation of losses in an acoustic signal in a room comprising multiple positions (P1, P2, P3, P4), wherein each position comprises at least one sending point (6) and at least one receiving point (4), and wherein the losses occur between a sending point (6) of a first position and a receiving point (4) of a second position, the process comprising:

transmitting an acoustic signal (S) from the sending point (6) of the first position to the receiving point(4) of the second position via an electrical path,

providing a first electro-acoustic means (M1, M2, M3, M4) for receiving the acoustic signal (S) in the vicinity of the sending point (6) of the first position,

providing a second electro-acoustic means (L1, L2, L3, L4) for reproducing the acoustic signal (S) in the vicinity of the receiving point (4) of the second position,

determining a parameter of the acoustic path between the sending point (6) of the first position and the receiving point(4) of the second position that is capable of being used to compensate losses due to echoes, feedback or ambient noise, and

generating a compensating acoustic signal via the second electro-acoustic means (L1, L2, L3, L4) using the parameter, whereby the losses in the acoustic signal are compensated

wherein the values of the parameter or of each parameter for at least one given transmission path is stored and used to control the signal level, and

wherein the values of the parameter or of each parameter is stored in the form of an attenuation matrix.

2. A process according to claim 1, wherein the attenuation of the signal (S) between the sending point (6) and the receiving point (4) is determined as the parameter.

3. A process according to claim 2, wherein upon exceeding a maximum value of attenuation, the signal level for a given position (P1 through P4) is amplified.

4. A process according to claim 2, wherein upon undershooting a minimal value of attenuation, the signal level for the given position (P1 through P4) is attenuated.

5. A process according to claim 1, wherein the propagation time of the signal (S) along the acoustical path (A1 through A2) between the sending point (6) and receiving point (4) is determined as the parameter.

6. A process according to claim 5, wherein the signal (S) is delayed along the electrical path in dependence upon the propagation time of the signal (S).

7. A process according to claim 1, wherein acoustical or electrical echoes between the sending point (6) and the receiving point (4) are determined as the parameter.

8. A process according to claim 1, wherein an interference signal between the sending point (6) and the receiving point (4) is determined as the parameter.

9. A device for the compensation of losses of a signal (S) along a transmission path between at least one sending point (6) and at least one receiving point (4) in a room, comprising:

a controller (14) for the determination of the transmission path as well as for the detection of at least one parameter of an associated transmission function, at least one level meter (W1 through W2) arranged in combination with at least one echo canceller (K1 through K2) between the sending point (6) and the receiving point (4) and connected to said controller for the control of the signal level at a given position (P1 through P4) along the transmission path.

10. A device according to claim 9, wherein an attenuation element (10) is provided between the sending point (6) and the receiving point (4).

11. A device according to claim 9, wherein a delay element (12) is provided between the sending point (6) and the receiving point (4).

12. A device according to claim 9, wherein the echo canceller (K1 through K2) is a digital filter, particularly an FIR-filter.

13. A device according to claim 9, wherein at least one microphone (M1 through M4) serves as a sender at the sending point (6).

14. A device according to claim 9, wherein at least one loudspeaker (L1 through L4) serves as a receiver at the receiving point (4).

15. A vehicle having a passenger space defined therein, said vehicle provided with a device for compensation of losses of a signal (S) along a transmission path between at least one sending point (6) and at least one receiving point (4) in said passenger space, said device comprising:

a controller (14) for determining the transmission path as well as for detecting at least one parameter of an associated transmission function,

at least one level meter (W1 through W2) arranged in combination with at least one echo canceller (K1 through K2) between the sending point (6) and the receiving point (4) and connected to said controller for the control of the signal level at a given position (P1 through P4) along the transmission path.