Cause of echo in VoIP conversation

[fisico30]

Hello Forum,

it can happen that in a VoIP conversation we hear some echo, i.e. we hear our voice, with a certain delay...

We speak and the signal goes to the receiving party. Why would a copy of our voice signal make a round trip and come back to us?
What causes that "reflection" of the signal?

thanks,
fisico3o

 

[berkeman]

Hello Forum,

it can happen that in a VoIP conversation we hear some echo, i.e. we hear our voice, with a certain delay...

We speak and the signal goes to the receiving party. Why would a copy of our voice signal make a round trip and come back to us?
What causes that "reflection" of the signal?

thanks,
fisico3o

If their microphone can hear their speaker, you will get an echo.

You don't get echos if they are using a handset, since the speaker is covered by their ear, and the microphone generally can't hear the speaker...