JP2010016564A5

JP2010016564A5 -

Info

Publication number: JP2010016564A5
Application number: JP2008173816A
Authority: JP
Filing date: 2008-07-02
Publication date: 2011-04-14
Anticipated expiration: 2028-07-02

Claims

Provided in an audio transmission system that outputs a far-end signal transmitted from a far-end side to a near-end side from a near-end speaker and transmits a near-end signal input from a near-end microphone to the far-end side. An audio signal processing device,
An echo canceller for canceling echo from the near-end signal input to the microphone based on the far-end signal supplied to the speaker;
An environment change detection unit that detects a change in a near-end sound collection environment that affects an acoustic transfer function on the near-end side where the speaker and the microphone are provided;
The echo canceller includes an adaptive filter that generates a pseudo echo signal based on the far-end signal, and a coefficient update control unit that converges an echo canceller coefficient that is a filter coefficient of the adaptive filter by coefficient update processing, A coefficient update control unit, when the environmental change detection unit detects a change in the near-end sound collection environment, a convergence speed of the echo canceller coefficient according to a lapse of time after detection of the change in the near-end sound collection environment change the coefficient update processing to reduce the,
The environment change detection unit detects a vehicle arrival at the near end as a change in the near end sound collection environment .

The coefficient update control unit reduces a convergence speed of the echo canceller coefficient by reducing a step size of a coefficient update process of the echo canceller coefficient according to a lapse of time after detection of a change in the near-end sound collection environment. The audio signal processing apparatus according to claim 1 , wherein:

The coefficient update control unit is configured to be able to switch between a plurality of coefficient update processes with different convergence speeds so that the convergence speed decreases with the passage of time after detection of a change in the near-end sound collection environment. The audio signal processing apparatus according to claim 1 , wherein the plurality of coefficient update processes are switched.

The coefficient update control unit, when a change of the near end sound collection environment is detected, performs the coefficient updating processing of RLS method, followed by claim 3, characterized in that the coefficient updating processing NLMS Algorithm Audio signal processing device.

The coefficient update control unit, said when the near-end sound collection environment is detected, the audio signal processing apparatus according to any one of claims 2 to 4, characterized in that clearing the echo canceller coefficients before detection .

The echo canceller further includes a cancellation execution filter different from the adaptive filter, and a coefficient transfer unit that transfers the echo canceller coefficient from the adaptive filter to the cancellation execution filter,
The coefficient transfer unit compares the echo cancellation effect of the adaptive filter and the cancellation execution filter, and determines that the adaptive filter cancels the echo of the near-end signal significantly more than the cancellation execution filter. transfer the echo canceller filter coefficients to the canceling execution filter, the cancel execution filter, according to claim 1 to 5, characterized in that to perform the echo cancellation by using the echo canceller coefficients transferred from the adaptive filter The audio signal processing device according to any one of the above.

Provided in an audio transmission system that outputs a far-end signal transmitted from a far-end side to a near-end side from a near-end speaker and transmits a near-end signal input from a near-end microphone to the far-end side. An audio signal processing device,
An echo canceller for canceling echo from the near-end signal input to the microphone based on the far-end signal supplied to the speaker;
An environment change detection unit that detects a change in a near-end sound collection environment that affects an acoustic transfer function on the near-end side where the speaker and the microphone are provided;
Wherein by learning the noise at the near end sound collection environment from the near-end signal, and a noise suppression unit for suppressing noise of the near end signal,
The echo canceller includes an adaptive filter that generates a pseudo echo signal based on the far-end signal, and a coefficient update control unit that converges an echo canceller coefficient that is a filter coefficient of the adaptive filter by coefficient update processing, A coefficient update control unit, when the environmental change detection unit detects a change in the near-end sound collection environment, a convergence speed of the echo canceller coefficient according to a lapse of time after detection of the change in the near-end sound collection environment Change the coefficient update process to reduce
The noise suppressor, when the environment change detecting part which detects a change in the near-end sound collection environment to reset the noise learning before detection, features and to Ruoto voice to start a noise learning new Signal processing device.

This is performed in a voice transmission system that outputs a far-end signal transmitted from a far-end side to a near-end side from a near-end speaker and transmits a near-end signal input from a near-end microphone to the far-end side. An audio signal processing method comprising:
Echo cancellation processing for canceling echo from the near-end signal input to the microphone based on the far-end signal supplied to the speaker;
An environment change detection process for detecting a change in a near-end sound collection environment that affects an acoustic transfer function on the near end side where the speaker and the microphone are provided, and
The echo cancellation process includes an adaptive filter process that generates a pseudo echo signal based on the far-end signal, and a coefficient update control process that converges an echo canceller coefficient that is a filter coefficient of the adaptive filter process by a coefficient update process. The coefficient update control process is configured such that when the change in the near-end sound collection environment is detected in the environment change detection process, the echo canceller according to a lapse of time after the change in the near-end sound collection environment is detected. Change the coefficient update process to reduce the coefficient convergence speed ,
The audio signal processing method characterized in that the environment change detection process detects the arrival of a vehicle at the near end side as a change in the near end sound collection environment .