Acoustic echo suppression device and acoustic echo suppression method

Patent metadata

Field	Value
Publication number	US-10798247-B2
Application number	US-201816489897-A
Country	US
Kind code	B2
Filing date	Jan 29, 2018
Priority date	Mar 16, 2017
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A microphone picks-up voice of a driver. A first echo suppression unit outputs a voice signal after first echo suppression based on a voice signal of the driver and a voice signal after echo suppression in the past (first reference signal) stored in a buffer memory. A second echo suppression unit outputs a voice signal after second echo suppression based on a voice signal of the driver and a voice signal after the echo suppression in the past (second reference signal) stored in a buffer memory. An output signal selector selects one of the voice signals after the first echo suppression or the voice signal after the second echo suppression according to a detection result of the presence or absence of a system variation by a system variation detector, and causes a speaker to output the selected voice signal.

First claim

The invention claimed is:

1. An acoustic echo suppression device that suppresses acoustic echo in a room where a sound pick-up unit is installed, the device comprising:
a first filter processor which is connected to the sound pick-up unit and outputs a first sound signal obtained by updating an echo component included in a picked-up sound signal acquired by the sound pick-up unit at a first rate;
a second filter processor which is connected to the sound pick-up unit and outputs a second sound signal obtained by updating the echo component included in the picked-up sound signal at a second rate faster than that of the first filter processor, against a sudden variation in a sound field environment in the room;
a detector which detects presence or absence of the variation in the sound field environment in the room; and
an output selector which selects one of the first sound signal and the second sound signal according to a detection result of the presence or absence of the variation in the sound field environment in the room and causes a voice output unit to output the selected sound signal.

2. The acoustic echo suppression device of claim 1 ,
wherein an update rate of a coefficient of a filter unit included in the second filter processor is faster than an update rate of a coefficient of a filter unit included in the first filter processor.

3. The acoustic echo suppression device of claim 1 ,
wherein the detector detects the presence or absence of the variation in the sound field environment in the room based on the first sound signal and the second sound signal.

4. The acoustic echo suppression device of claim 1 ,
wherein, when the first sound signal is smaller than the second sound signal, the detector determines that there is no variation in the sound field environment in the room, and, when the second sound signal is smaller than the first sound signal, the detector determines that there is the variation in the sound field environment in the room.

5. The acoustic echo suppression device of claim 1 , further comprising:
a first reference signal memory which stores the first sound signal output from the first filter processor, as a first reference signal; and
a second reference signal memory which stores the second sound signal output from the second filter processor, as a second reference signal,
wherein the first filter processor generates and outputs the first sound signal based on the picked-up sound signal and the first reference signal stored by the first reference signal memory, and
the second filter processor generates and outputs the second sound signal based on the picked-up sound signal and the second reference signal stored by the second reference signal memory.

6. The acoustic echo suppression device of claim 1 ,
wherein, when it is detected that there is no variation in the sound field environment in the room, the output selector selects and outputs the first sound signal, and when it is detected that there is the variation in the sound field environment in the room, the output selector selects and outputs the second sound signal.

7. The acoustic echo suppression device of claim 1 , further comprising:
a third filter processor which outputs a third sound signal obtained by updating the echo component included in the picked-up sound signal, at a third rate faster than that of the first filter processor and the second filter processor, against the sudden variation in the sound field environment in the room,
wherein the output selector selects any one of the first sound signal, the second sound signal, and the third sound signal, and causes the voice output unit to output the selected sound signal.

8. The acoustic echo suppression device of claim 7 ,
wherein an update rate of a coefficient of the filter unit included in the third filter processor is faster than an update rate of a coefficient of the filter unit included in the first filter processor and an update rate of a coefficient of the filter unit included in the second filter processor.

9. The acoustic echo suppression device of claim 7 ,
wherein the detector detects the presence or absence of the variation in the sound field environment in the room based on the first sound signal, the second sound signal, and the third sound signal.

10. The acoustic echo suppression device of claim 7 ,
wherein, when the first sound signal is smaller than the second sound signal, the detector determines that there is no variation in the sound field environment in the room, when the second sound signal is smaller than the first sound signal, the detector determines that there is the variation in the sound field environment in the room, and when the third sound signal is smaller than the second sound signal, the detector further determines that there is a large variation in the sound field environment in the room.

11. The acoustic echo suppression device of claim 7 , further comprising:
a first reference signal memory which stores the first sound signal output from the first filter processor as a first reference signal;
a second reference signal memory which stores the second sound signal output from the second filter processor as a second reference signal; and
a third reference signal memory which stores the third sound signal output from the third filter processor as a third reference signal,
wherein the first filter processor generates and outputs the first sound signal based on the picked-up sound signal and the first reference signal stored by the first reference signal memory,
the second filter processor generates and outputs the second sound signal based on the picked-up sound signal and the second reference signal stored by the second reference signal memory, and
the third filter processor generates and outputs the third sound signal based on the picked-up sound signal and the third reference signal stored by the third reference signal memory.

12. The acoustic echo suppression device of claim 7 ,
wherein, when it is detected that there is no variation in the sound field environment in the room, the output selector selects and outputs the first sound signal, when it is detected that there is the variation in the sound field environment in the room, the output selector selects and outputs the second sound signal, and when it is detected that there is a large variation in the sound field environment in the room, the output selector further selects and outputs the third sound signal.

13. The acoustic echo suppression device of claim 1 ,
wherein the detector detects the presence or absence of the variation in the sound field environment in the room based on an image captured by a camera that images the room.

14. The acoustic echo suppression device of claim 1 ,
wherein the detector detects the presence or absence of the variation in the sound field environment in the room based on an output signal of a sensor that detects a state in the room.

15. The acoustic echo suppression device of claim 1 ,
wherein the detector detects the presence or absence of the variation in the sound field environment in the room based on sound signals from three or more sound detectors that detect sounds in the room.

16. An acoustic echo suppression method of suppressing acoustic echo in a room where a sound pick-up unit is installed, the method comprising:
outputting a first sound signal obtained by updating an echo component included in a picked-up sound signal acquired by the sound pick-up unit at a first rate;
outputting a second sound signal obtained by updating the echo component included in the picked-up sound signal, at

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Miyamoto Masanari
• Ohashi Hiromasa
• Tanaka Naoya

Classifications

• H04M9/085

  using digital techniques (H04M9/082 takes precedence) · CPC title

• H04R3/02

  for preventing acoustic reaction {, i.e. acoustic oscillatory feedback (specially adapted for hearing aids H04R25/453)} · CPC title

• H04M9/082 Primary

  using echo cancellers (echo cancellers per se H04B3/23) · CPC title

• H04R2410/01

  Noise reduction using microphones having different directional characteristics · CPC title

• B60R11/02

  for radio sets, television sets, telephones, or the like; Arrangement of controls thereof · CPC title