Audio systems for providing isolated listening zones

Patent metadata

Field	Value
Publication number	US-9847081-B2
Application number	US-201514828991-A
Country	US
Kind code	B2
Filing date	Aug 18, 2015
Priority date	Aug 18, 2015
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

An audio system includes a plurality of near-field speakers arranged in a listening area. A plurality of cross-talk cancellation filters are coupled to the speakers. The speakers and the filters are arranged to provide first and second listening zones in the listening area such that audio from the first listening zone is cancelled in the second listening zone and vice versa. The system also includes at least one audio source providing audio content. Volume-based equalization circuitry receives an audio signal representing audio content for the first listening zone from the audio source and controls a volume adjustment applied to the audio signal to control a volume of audio in the first listening zone. The circuitry limits attenuation or amplification of a first frequency portion of the audio signal when a volume setting differential corresponding to a difference between volume settings for the first and second zones exceeds a predetermined value.

First claim

What is claimed is:

1. An audio system comprising:
a plurality of near-field speakers arranged in a listening area;
a plurality of cross-talk cancellation filters coupled to the near-field speakers, the near-field speakers and the cross-talk cancellation filters being arranged to provide first and second listening zones in the listening area in which audio from the first listening zone is cancelled in the second listening zone and vice versa;
at least one audio source for providing identical audio content to both the first listening zone and the second listening zone;
first volume-based equalization circuitry configured to receive a first audio signal representing audio content for the first listening zone from the at least one audio source, and to control a volume adjustment applied to the first audio signal thereby to control a volume of audio in the first listening zone based on a first volume setting; and
second volume-based equalization circuitry configured to receive a second audio signal representing audio content for the second listening zone, and to control a volume adjustment applied to the second audio signal thereby to control a volume of audio in the second listening zone based on a second volume setting,
wherein the first volume-based equalization circuitry is configured to determine whether a volume setting differential between the first volume setting for the first listening zone and the second volume setting for the second listening zone exceeds a predetermined threshold, and if so, limit attenuation of a first frequency portion of the first audio signal to a corresponding amount of attenuation of a second frequency portion of the first audio signal, thereby to achieve a desired volume of audio in the first listening zone based on the first volume setting while maintaining a substantially balanced spectrum in the first listening zone, wherein the amount of attenuation of the second frequency portion of the first audio signal depends on an amount of leakage of a second frequency portion of the second audio signal from the second listening zone into the first listening zone.

2. The audio system of claim 1 , wherein the second volume-based equalization circuitry is configured to limit amplification of the second frequency portion of the second audio signal when the volume setting differential exceeds the predetermined value.

3. The audio system of claim 1 , wherein the first frequency portion of the first audio signal is a low frequency portion and the second frequency portions of both the first audio signal and the second audio signal is a high frequency portion.

4. The audio system of claim 1 , further comprising control circuitry configured to provide the first and second volume-based equalization circuitry with a volume control signal, wherein the first volume-based equalization circuitry is configured to determine the volume setting differential based on information provided in the volume control signal.

5. The audio system of claim 1 , wherein the first volume-based equalization circuitry only limits the attenuation of the first frequency portion of the first audio signal when the volume setting differential exceeds the predetermined threshold and the first and second audio signals represent the same audio content.

6. The audio system of claim 1 , wherein the first frequency portion of the first audio signal is a low frequency portion and the second frequency portion of the second audio signal is a high frequency portion, and wherein the amount of leakage of the second frequency portion of the second audio signal from the second listening zone into the first listening zone depends on an amount of cancelation that is attainable for the high frequency portion of the second audio signal in the first listeing zone.

Assignees

• Bose Corp

Inventors

• Oswald Charles
• Salvador Eduardo T
• Vautin Jeffery R
• Dublin Michael S
• Tengelsen Daniel Ross
• Ickler Christopher B

Classifications

• H03G3/20

  Automatic control ({H03G3/005 takes precedence;} combined with volume compression or expansion H03G7/00) · CPC title

• H04R2499/13

  Acoustic transducers and sound field adaptation in vehicles · CPC title

• H03G5/165

  Equalizers; Volume or gain control in limited frequency bands · CPC title

• H04S7/302

  Electronic adaptation of stereophonic sound system to listener position or orientation (H04S7/301 takes precedence) · CPC title

• H04S3/008

  in which the audio signals are in digital form, i.e. employing more than two discrete digital channels (data reduction aspects thereof based on psychoacoustics G10L19/02) · CPC title