Several autoplaying Vimeo Embeds unmute all at once

Several auto-playing Vimeo Embeds that are on the same page play sounds simultaneously when only one of the embed videos is unmuted. See the issue here:

This is the custom code I’ve used for my video embeds:

<div style="padding:56.25% 0 0 0;position:relative;">
<iframe src="" 
frameborder="0" allow="autoplay; fullscreen" 

Any help appreciated, thank you (Also this is my first forum post I hope I included all the right info!)