1. Does WinShark show the audio is arriving at the destination?

2. If using a browser client, you might be attaching the stream to the video element too late. Attaching should be done via a handler of the ontrack event (which verto does).

3. If using a browser client, and you're missing inbound audio, something might be pausing or muting the video element used by the call. For example, iOS pauses the call video element if any other video element having an audio track plays.