I found that there is sound noise when more than 8 people in the same meeting.
It’s easy to reproduce.
I capture the audio packets sended by browser and play it, it sounds fine, so it’s not a problem of audio source.
I’m not sure whether it’s a bug of mediasoup or a bug of webrtc itself.
mediasoup does not care if RTP is voice or noise
WebRTC echo cancellation in browsers is not perfect, but you can do noise reduction in client side by using WebAudio and complex algorithms. Nothing that I can show examples of.