G.167 compliance of an AEC

Started by Akshu Agrawal in Echo Cancellation14 years ago

Hello all, I am working on an acoustuic echo canceller project and I require my AEC to be G.167 compliant. Please let me know on what...

Hello all, I am working on an acoustuic echo canceller project and I require my AEC to be G.167 compliant. Please let me know on what essential parameters should i test my code and also if any tools are available to check the compliance. Thanks, Regards, Akshu.


implement AEC on DSP

Started by popf...@gmail.com in Echo Cancellation12 years ago

Hi,all I have implement an AEC algorithm (Frequency Domain NLMS) on DSP (TI c5509), but when I test it in real room the ERLE is 16dB(with...

Hi,all I have implement an AEC algorithm (Frequency Domain NLMS) on DSP (TI c5509), but when I test it in real room the ERLE is 16dB(with white noise), will test by compositive speech source with line_in the ERLE is 25dB. But, I always see that some AEC product's ERLE can get 25dB-30dB, So I want to konw the method they test. 1,what's the test source. white noise or speech signal? ...


AEC Testing speech samples

Started by sunvict in Echo Cancellation15 years ago 2 replies

Hi, I need some speech samples to test my AEC algorithm. Can any one send me some sample files. Which is the best algorithm we can...

Hi, I need some speech samples to test my AEC algorithm. Can any one send me some sample files. Which is the best algorithm we can use for handsfree echo cancellation.I am considering a single channel. sunvict


How to simulate room response in G.167 AEC?

Started by dingkesun in Echo Cancellation13 years ago

Hi, All I??m doing a project about G.167 compliant AEC. In the standard, it says: For teleconference systems, the...

Hi, All I??m doing a project about G.167 compliant AEC. In the standard, it says: For teleconference systems, the reverberation time averaged over the transmission bandwidth shall be typically 400 ms; For hands-free telephones and videophones, the reverberation time averaged over the transmission bandwidth


How to simulate the echo in G.167 AEC specs?

Started by ding...@hotmail.com in Echo Cancellation13 years ago

Hi, All I'm currently doing a project on G.167 compliant AEC. For teleconference systems, the reverberation time averaged over the...

Hi, All I'm currently doing a project on G.167 compliant AEC. For teleconference systems, the reverberation time averaged over the transmission bandwidth shall be typically 400 ms; For hands-free telephones and videophones, the reverberation time averaged over the transmission bandwidth shall be typically 500 ms; For mobile radio telephones


does any one konw any details about GIPS' acoustic echo cancellation?

Started by bochencb2009 in Echo Cancellation9 years ago

hi all: GIPS's AEC is very famous especially when it was used by Skype. it will be very grateful that if anyone could share some details about...

hi all: GIPS's AEC is very famous especially when it was used by Skype. it will be very grateful that if anyone could share some details about its algorithms, such as what kind of adaptive filter algorithm it use, how about the adjustment of step size and so on. thanks very much


AEC performance measures

Started by hetal_nayan in Echo Cancellation16 years ago

Hello all, What are the performance measures besides G.167 that need to be considered for good perceptual quality ...

Hello all, What are the performance measures besides G.167 that need to be considered for good perceptual quality speakerphone? Thanks! Nayan Gaywala


RE: acoustic echo cancellation performance?

Started by Shaw, David G David in Echo Cancellation16 years ago 1 reply

From experience you should not count on echo cancellation like you expect from the LEC numbers you may be familiar with. Measure...

From experience you should not count on echo cancellation like you expect from the LEC numbers you may be familiar with. Measure the microphone noise floor and make sure that your residual error is not dominated by it. It is VERY, VERY hard to reach 30dB from just the AEC. Issu


acoustic echo cacellation performance?

Started by andrew_xiang in Echo Cancellation16 years ago 1 reply

Anyone implemented a system that get you 30dB of reduction for AEC? In my system, I only get 4X for voice signal. I will give it...

Anyone implemented a system that get you 30dB of reduction for AEC? In my system, I only get 4X for voice signal. I will give it a try with white noise. But seems 30X is far away. But I don't expect users to utter white noise when they speak. My calculation:


Does anybody know where I can get C source code for the AEC?

Started by zhang_zhh in Echo Cancellation17 years ago 4 replies

Hi all, I am working on the H323 VoIP terminal in the PC environment. but in order to cancel the echo from speaker even from...

Hi all, I am working on the H323 VoIP terminal in the PC environment. but in order to cancel the echo from speaker even from the headset(I am not sure if this is acoustic echo or line echo. but we do hear a faint echo intermittently, any idea? ), I need a basic acoustic echo


Residual Echo suppression for AEC

Started by seshagiri_kodandapani in Echo Cancellation15 years ago

Hi all, Where can I get any information on residual echo suppression techniques for Acoustic Echo canceller implemented in...

Hi all, Where can I get any information on residual echo suppression techniques for Acoustic Echo canceller implemented in "time domain". Thanks Seshagiri.


Echo cancellation using 2 microphone

Started by dqkn...@yahoo.com in Echo Cancellation11 years ago

Hi everyone, I am involving in the Echo cancellation using 2 microphones. The main mic (mic1) is placed near local speaker while the another...

Hi everyone, I am involving in the Echo cancellation using 2 microphones. The main mic (mic1) is placed near local speaker while the another (mic2) is near the echo and noise source. Mic2 signal is considered as reference signal in single channel AEC for the LMS algorithm. The ERLR of system now is very poor (~12dB), and the voice quality is degraded also. I also tried to shorten the distance ...


Re:Re: Does anybody know where I can get C source code fo r the AEC?

Started by Anonymous in Echo Cancellation17 years ago

Hello Maximus, There are algorithms that do not rely on level differences to determine if double-talk is present. These algorithms...

Hello Maximus, There are algorithms that do not rely on level differences to determine if double-talk is present. These algorithms do not suffer from input level differences. I would suggest you do a patent search on echo canceller double-talk detectors. One detector I k


Test signals for acoustic echo canceller

Started by Satyanarayana PK in Echo Cancellation16 years ago

Hello all, We are working on acoustic echo canceller(AEC). We have finished the development work and tested it for simulated...

Hello all, We are working on acoustic echo canceller(AEC). We have finished the development work and tested it for simulated signals. Now we want to test the same for real-time environment(sort of field test). We are stuck at recording the echo signal in a small room. Can anybo


How to design decorrelation filter

Started by dqkngoc in Echo Cancellation13 years ago

Hi everyone, It's glad for me to become a new member in echocancel group that i am also working on this problem. I want to simulate AEC...

Hi everyone, It's glad for me to become a new member in echocancel group that i am also working on this problem. I want to simulate AEC algorithm using 2 pcm audio file for speaker signal and microphone signal. These 2 pcm signal files have 16KHz sampling frequency, so i want to design decorrelation filter that working optimise with 16 KHz sampling frequency. Anyone please advice me h...


ITU-T P.340 compliance

Started by prad...@ittiam.com in Echo Cancellation10 years ago

hi all, This is regarding compliance to ITU-T Rec. P.340. As per p.340, Terminal coupling loss (TCLwst) is to be calculated after...

hi all, This is regarding compliance to ITU-T Rec. P.340. As per p.340, Terminal coupling loss (TCLwst) is to be calculated after normalizing the TCL for the values of RLR (receiver sensitivity rating) and SLR (sending sensitivity rating). If we plan to test the performance of the AEC software module (offline testing) then how do we calcuate the TCL values. What nominal values of RLR and...


How to synchronize the reference signal and the echoed signal?

Started by Ding Ke in Echo Cancellation13 years ago

Hi All I write a sound recording tool to generate the test vector for AEC. First, a sound file is played as the reference signal (far...

Hi All I write a sound recording tool to generate the test vector for AEC. First, a sound file is played as the reference signal (far end speaker) through the loudspeaker. In order to simulate the near end speaker, the person say some words when it is recorded at the same time. But how to synchronize the reference signal and the recorded echoed signal?