In Safari on iOS 11 Beta setting the audio volume on a video element which is connected to a remote PeerConnection does not have an effect. It does work in Safari Beta on Mac OS Sierra as well as Safari Technology Preview on Mac OS Sierra. Steps to reproduce: 1. Visit https://webrtc.github.io/samples/src/content/peerconnection/pc1/ 2. Click on "Start" and allow access to your camera 3. Click on "Call" and wait for the video on the right to be established. You should be able to see yourself in 2 video windows and hear yourself. 4. Open up the console and type `document.querySelectorAll('video')[1].volume = 0` Expected Result: You will mute the video element and no longer be able to hear yourself. Actual Result: You can still hear yourself. Also the volume property still returns as 1 instead of 0. Again this works in Safari on Mac OS, just not on iOS.
<rdar://problem/34134905>
On iOS volume is controlled by the user only, however you should be able to mute a video/audio element by setting the 'muted' attribute.