Motor vehicle audio system

• US 9,602,948 B2
• Filed: 03/30/2016
• Issued: 03/21/2017
• Est. Priority Date: 08/20/2014
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: Barksdale, Tobe Z., Holmi, Douglas J.
• Primary Examiner(s): Lao, Lun-See
• Application Number:
  US15/084,980
• Publication Number:
  US 20160212565A1
• Time in Patent Office: 356 Days
• Field of Search: 381/86, 381 17- 23, 381/123, 381/63, 381104-107, 381/109, 381/302, 381/310
• US Class Current: 1/1
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: H04R 1/028 associated with devices performing functions other than acoustics, e.g. electric candles
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 5/023 in a chair, pillow
• CPC Class Codes: H04S 2400/13 Aspects of volume control, not necessarily automatic, in stereophonic sound systems
• CPC Class Codes: H04S 7/303 Tracking of listener position or orientation
• CPC Class Codes: H04S 7/308 Electronic adaptation dependent on speaker or headphone connection

Abstract

A motor vehicle audio system, and a method of operating such a system. There is at least one rear far-field speaker that is located behind a front seat of the motor vehicle, and at least one near-field speaker located in front of the far-field speaker and close to an intended position of a listener'"'"'s head. There is an audio signal processor configured to detect when the rear far-field speaker is shut off while the near-field speaker remains on, and in response automatically increase the output energy of the near-field speaker.

Claims

1. A method of operating a motor vehicle audio system that has at least one rear far-field speaker that is located behind front seats of the motor vehicle, wherein the front seats of the motor vehicle comprise a driver headrest and a passenger headrest, and wherein the motor vehicle audio system comprises a pair of near-field speakers in each such front seat headrest, the method comprising:

detecting when a rear far-field speaker is shut off while at least one near-field speaker remains on; and

in response

automatically operating the pair of near-field speakers in a headrest so as to deliver approximately the same audio energy to the expected location of each ear of a front seat listener'"'"'s position as was delivered before the far-field speaker was shut off.

2. The method of claim 1 wherein operating the pair of near-field speakers in a headrest so as to deliver approximately the same audio energy to the expected location of each ear of a front seat listener'"'"'s position as was delivered before the far-field speaker was shut off comprises adjusting an equalization of the pair of near field speakers in a headrest.

3. The method of claim 1 wherein a transfer function from each far-field speaker that was shut off to the expected location of each ear of a front seat listener'"'"'s position is known, and wherein operating the pair of near-field speakers in a headrest so as to deliver approximately the same audio energy to the expected location of each ear of a front seat listener'"'"'s position as was delivered before the far-field speaker was shut off comprises operating the pair of near-field speakers so as to approximate the transfer functions from each far-field speaker that was shut off, to the expected location of each ear of a front seat listener'"'"'s position.

4. The method of claim 1 wherein the motor vehicle audio system comprises a user-operated switch that is part of an audio head unit and that can be operated so as to shut off one or more far-field speakers.

5. The method of claim 1 wherein the audio system comprises left and right rear door speakers.

6. The method of claim 1 wherein operating the pair of near-field speakers in a headrest so as to deliver approximately the same audio energy to the expected location of each ear of a front seat listener'"'"'s position as was delivered before the far-field speaker was shut off comprises using binaural signal filters to modify the outputs of the pair of near-field speakers in a headrest.

7. The method of claim 6 wherein the binaural signal filters are accomplished using a programmed digital signal processor.

8. The method of claim 1 wherein the motor vehicle audio system comprises an automatic switch that is based on sensing an occupant of a motor vehicle seat behind the front seat.

9. The method of claim 8 wherein the automatic switch shuts off a rear far-field speaker when an occupant of a motor vehicle seat behind the front seat is sensed.

10. A motor vehicle audio system for a motor vehicle with front seats that comprise a driver headrest and a passenger headrest, comprising:

at least one rear far-field speaker that is located behind the front seats of the motor vehicle;

a pair of near-field speakers in each of the driver and passenger headrests; and

an audio signal processor configured to detect when a rear far-field speaker is shut off while at least one near-field speaker remains on, and in response automatically operating the pair of near-field speakers in a headrest so as to deliver approximately the same audio energy to the expected location of each ear of a front seat listener'"'"'s position as was delivered before the far-field speaker was shut off.

11. The system of claim 10 wherein operating the pair of near-field speakers in a headrest so as to deliver approximately the same audio energy to the expected location of each ear of a front seat listener'"'"'s position as was delivered before the far-field speaker was shut off comprises adjusting an equalization of the near field speaker.

12. The system of claim 10 wherein a transfer function from each far-field speaker that was shut off to the expected location of each ear of a front seat listener'"'"'s position is known, and wherein the audio signal processor automatically increases the output energy of the pair of near-field speakers in a headrest so as to deliver approximately the same audio energy to the expected location of each ear of a front seat listener'"'"'s position as was delivered before the far-field speaker was shut off, by operating the pair of near-field speakers so as to approximate the transfer functions from each far-field speaker that was shut off, to the expected location of each ear of a front seat listener'"'"'s position.

13. The system of claim 10 wherein the at least one rear far-field speaker comprises a plurality of rear far-field speakers, and wherein the audio signal processor automatically increases the output energy of the pair of near-field speakers in a headrest by operating the pair of near-field speakers in a headrest so as to approximately replace the audio energy lost at the expected location of each ear of a front seat listener'"'"'s position.

14. The system of claim 10 further comprising a user-operated switch that is part of an audio head unit and that can be operated so as to shut off the far-field speaker.

15. The system of claim 10 wherein the audio system comprises left and right rear door speakers.

16. The system of claim 10 wherein operating the pair of near-field speakers in a headrest so as to deliver approximately the same audio energy to the expected location of each ear of a front seat listener'"'"'s position as was delivered before the far-field speaker was shut off comprises using binaural signal filters to modify the outputs of the pair of near-field speakers in a headrest.

17. The system of claim 16 wherein the binaural signal filters are accomplished using a programmed digital signal processor.

18. The system of claim 10 wherein the motor vehicle audio system comprises an automatic switch that is based on sensing an occupant of a motor vehicle seat behind the front seat.

19. The system of claim 18 wherein the automatic switch shuts off a rear far-field speaker when an occupant of a motor vehicle seat behind the front seat is sensed.