Muting an embedded vimeo video

Question

On a website I am building I have a vimeo video embedded. The client needs to keep the sound on the video obviously for people that find it on vimeo. However for her website

Answer 1

I tried the examples in the answers with no luck. After looking into the documentation I noticed there is missing the parameter &player_id=IFRAME_ID. Maybe something changed in the Vimeo API, anyway the following example works for me: