How to turn off acoustic echo cancellation

Here are some suggestions for evaluating an AEC-based conferencing system when you are in the remote room and thereвЂ™s a demo going on in the local room. Also you shouldВ be at the far-end of the system and listen to what you hear coming back to you from the local talkers in the room. The reality is that you always have to listen to the system in a variety of conditions. WhatвЂ™s too much latency? Approximately anything over 20 msec would be considered high if you were contemplating doing sound reinforcement in the room with the echo cancelled signal. If you have high latency through the algorithm then it may be unnatural to use the same feed for reinforcement in the room.

In the real-world the AEC wonвЂ™t adapt that quickly because local talker audio will prevent the system from adapting as quickly. If your AEC has a fast convergence rate then any echo heard by changes in the acoustic path in the local room should become inaudible very quickly. Yes, you need a tail time that is suitable for your application, i.e., if your room is acoustically large, a higher tail-time will make it possible for you to remove echoes that persist longer in the room. While there are parameters used to describe AEC systemsВ on datasheets such as tail-time, convergence rate, and latency, these terms should be considered more marketingВ descriptions than real-world performance indicators. Some systems may reduce the bandwidth of the signal by suppressing different frequency bands of the signal to reduce residual echo. Some systems may suppress the signal more to prevent echoes from being sent back to the remote participants in order to keep the system вЂecho freeвЂ™. Some systems may let more residual echo be sent back to the remote participants in order to keep the system more вЂfull duplexвЂ™ or interactive. If not all AEC algorithms are the same, then how are they different? The real-world aspect is important for a number of reasons including: rooms are noisy, big, reverberant, the gain on microphones is not always the same, local talkers never stop talking, microphones get moved in the room, and microphones get muted and unmuted. An AEC algorithm for use in conference rooms typically will have been developed by a team with at one or more DSP experts, used in real-world settings, and been adjusted over several months or years of use to better accommodate the вЂreal-worldвЂ™ environment than the вЂlab-worldвЂ™ where the algorithm was originally created. Are they all the same? How do you you evaluate them? How does an end-user or integrator make a decision?ДЇirst, not all AEC based systems are the same principally becauseВ not all AEC algorithms are the same. There are many installed products with Acoustic Echo Cancellation (AEC).

How to turn off acoustic echo cancellation