Customer hearing own voice echo

Hi, Im using ari client to set up my asterisk, based on asterisk external media from github
I added a snoop channel that records the customer while playbacks run, so if he speaks we could stop the playbacks and transcribe whatever he says.
however i noticed that once this was up and running, when there was no playback running at all, whenever the customer would speak there would be an echo heard back at him, tried this from a mobile line as well as zoiper and got the same results
I wasnt able to find anything on this online so im asking here.
Thanks in advance.

Use a packet capture to examine the audio that is sent, and see if the echo is actually present in it.

working on it, but in either case what should i be looking at?

I’m not entirely clear where the echo is being heard. If it is on the snoop channel, and there is no B leg present, I don’'t see that it can be Asterisk. If there is a B leg present, more detail is required.

If it is at the caller end. I imagine that the playback has prevented their echo canceller training properly.

OK, I only read the body. The subject makes it clear that it is the caller end. In that case the problem is happening in their system, or at the boundary of the long delay (mobile air interface, or VoIP) network.

In order to cancel echoes (other echo suppression tactics would mute audio completely in one direction, which would completely break your design), the echo canceller need to have outgoing audio when it can be sure of there being no legitimate incoming audio. Although I haven’t studied the details, I also imagine that a fast adaptation is made when the call first starts, and then slow adjustments are made.

It sounds like you are not giving their system an opportunity to train. A variation on that is that it has trained, but at a time when there was a real echo, so, if, say you had a human answer and then forward them to the automated system, it could be trying to subtract out an echo that doesn’t actually exist.