CN101815237A

CN101815237A - Test method and device of acoustic echo canceller

Info

Publication number: CN101815237A
Application number: CN200910241781A
Authority: CN
Inventors: 李政
Original assignee: Beijing Jiaxun Feihong Electrical Co Ltd
Current assignee: Beijing Jiaxun Feihong Electrical Co Ltd
Priority date: 2009-12-07
Filing date: 2009-12-07
Publication date: 2010-08-25

Abstract

The invention discloses a test method and a device of acoustic echo canceller, which belong to field of acoustic echo processing, the realizing principle comprises the following steps: establishing an environment for generating acoustic echo, using a DSP play audio file to simulate the voice of a remote user, recording proximal end input, remote end output, remote end input and output ports of proximal end when playing the audio file, obtaining the energy curve of a corresponding port by a method for calculating mean square root of the audio data, and comparing the energy relationship of the proximal end input and the remote end output to test the effect of acoustic echo cancellation. The invention provides the necessary information for manufacturers of acoustic echo canceller to improve the products.

Description

A kind of method of testing and device to acoustic echo canceller

Technical field

The present invention relates to the acoustic echo process field, relate in particular to a kind of method of testing and device acoustic echo canceller.

Background technology

Acoustic echo is meant the sound of delivering to far-end after sound that loudspeaker plays is come out is picked up by microphone again, can acoustic echo be heard by remote subscriber and depend on two factors, one is the energy of acoustic echo, another one is the time-delay of whole echo path, general reach more than 30 milliseconds and echo will be felt when having certain energy and the existence of echo will be influenced communication effect in the time of seriously when time-delay.

The common way of eliminating echo at present is to increase acoustic echo canceller at near-end.The effect that echo is eliminated depends on multiple factor, except the definition of subjective feeling index as talking with the people, intelligibility, whether trail, whether echo is arranged, whether loud, whether exchange smoothness etc. relevant outside, also with size as the room, whether echo path is changed, whether two what is said or talked about, the size of loudspeaker volume, the distance of near-end Mike and loudspeaker, the speed of Echo Canceller convergence, two what is said or talked about threshold values, the Nonlinear Processing threshold value, whether detect narrow band signal, whether open the AGC function, the disposal ability of whether carrying out parameter settings such as noise reduction process and AEC is closely related.

General, it is complicated that acoustic echo is eliminated quantitative test, needs to use the laboratory and the instrument of specialty just can carry out.The present invention can carry out quantitative test to acoustic echo canceller.

Summary of the invention

The objective of the invention is to eliminate the quantitative test complicated problems, proposed a kind of method of testing and device acoustic echo canceller (AEC) at the present acoustic echo described in the background technology.

It is characterized in that, described method is to use DSP (Digital Signal Processing) to play voice document, replace Rin (far-end input) port that far-end Mike exports AEC to, export from Rout (near-end output) port, play by the near-end loudspeaker after power amplifier drives, sound is picked up by near-end Mike through acoustic echo path decay back;

When playing voice document, Sin (near-end input), Sout (far-end output), Rin and Rout are recorded, preserve the speech data that recording obtains;

Utilization is calculated the energy curve that root mean square method obtains corresponding port to described speech data, by the energy relationship between input of contrast near-end and the far-end output echo of acoustic echo canceller is eliminated effect and tests.

Described device is to set up a voice channel that has increased AEC at near-end between near-end user and remote subscriber; At near-end DSP is set, described DSP links to each other with Sin, Sout, Rin and Rout port respectively; DSP links to each other with PC by USB.

The present invention can finish the test to acoustic echo canceller easily, submits necessary information for the production firm of acoustic echo canceller carries out the product improvement.

Description of drawings

Fig. 1: acoustic echo testing apparatus schematic diagram;

Fig. 2: to the test result of acoustic echo canceller.

Embodiment

Below in conjunction with accompanying drawing, preferred embodiment is elaborated.Should be emphasized that following explanation only is exemplary, rather than in order to limit the scope of the invention and to use.

Build an environment that can produce acoustic echo: embodiment is for setting up a voice channel between near-end user and remote subscriber, use the DSP of near-end to play voice document then, replace the Rin port 3 that far-end Mike exports AEC to, export from the Rout port 4 of AEC afterwards, after driving, power amplifier plays back by near-end loudspeaker 1, sound is picked up by near-end Mike 2 through acoustic echo path decay back, the sound that picks up is echo, adjust the volume of near-end loudspeaker and the position between this loudspeaker and the near-end Mike, decapacitation AEC, make remote subscriber obviously hear echo, as shown in Figure 1.

The method that the test acoustic echo is eliminated is when DSP plays voice document, enable AEC, and the pcm stream data of Rin port, Rout port, Sin port 5,6 four ports of Sout port are taken off by USB sent to PC respectively, PC is preserved the data that obtain get off with the form of four files respectively: Sin.pcm, Sout.pcm, Rin.pcm, Rout.pcm.

Calculate the average level of four voice documents respectively, can choose 16 milliseconds or longer average time.Result of calculation is shown as shown in Figure 2 with graphics mode intuitively.Abscissa is the time, and its unit is second; Ordinate is a level, and its unit is dBm0.

Wherein, the energy of the level of Sin port reflection echo, the level reflection echo of Sout port is through the energy after the Echo Canceller.The data of contrast Sin and two curves of Sout or calculating are the AEC echo of having eliminated how many energy as can be seen, thereby realizes the test that acoustic echo is eliminated, as shown in Figure 2.

The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and is familiar with those skilled in the art in the technical scope of the present invention's exposure; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.

Claims

1. method of testing to acoustic echo canceller, it is characterized in that, described method is to use DSP to play voice document, replace the far-end input port that far-end Mike exports acoustic echo canceller to, export from the near-end output port, play by the near-end loudspeaker after power amplifier drives, sound is picked up by near-end Mike through acoustic echo path decay back;

Near-end input, far-end output, far-end input, near-end output to acoustic echo canceller when playing voice document are recorded, and preserve the speech data that recording obtains;

2. a kind of method of testing to acoustic echo canceller according to claim 1 is characterized in that described speech data is the pcm stream data.

3. a kind of method of testing according to claim 1 to acoustic echo canceller, it is characterized in that, when testing, must adjust the volume of described near section loudspeaker and the position between this loudspeaker and the described near-end Mike, the decapacitation acoustic echo canceller makes remote subscriber can obviously hear echo.

4. the testing apparatus to acoustic echo canceller of realizing method of testing in the claim 1 is characterized in that, described device is to set up a voice channel that has increased acoustic echo canceller at near-end between near-end user and remote subscriber; At near-end DSP is set, described DSP links to each other with near-end input, far-end output, far-end input, the near-end output port of acoustic echo canceller respectively; DSP reaches with PC by USB and links to each other.