Let’s imagine you are UserA and in a conversation with UserB. Echo is when your voice is retransmitted back to you by User B. The effects of this can be distracting and lead to poor user experience, especially in multiparty calls.
The most important take away here is that echo is not produced on the side where it is heard.
Example of a conversation with no acoustic echo cancellation (AEC):
- User 1 places an audio call to User 2
- User 1 is using a headset (composite device) as an audio device.
- User 2 is using a separate device for speakerphone and microphone (Non-Composite device) where speakerphone does not have an AEC. (acoustic echo cancellation).
- User 2 does not hear the echo from their end.
- User 1 hears his own echo when speaking.
Note: The Echo is produced when one of the users in multiparty call is using a separate device for speakerphone for audio output and a microphone phone for audio input or speakerphone with an inbuilt microphone which does not support AEC (acoustic echo cancellation).