auto pause iframe video and audio when another plays - audio

Question

I'm having difficulty figuring this out. I'm new to JS so I need some help!
I've managed to auto-pause audio when another audio plays BUT I now need more than that. I need this to include audio and iframe videos.
My ask is, is it possible to auto-pause an iframe video if audio starts playing, and vice versa?
Thanks in advance.
I've tried the below and it doesn't do exactly what I need. Please help.
<script>
var audios = document.getElementsByTagName('audio');
for (var i = 0, len = audios.length; i < len;i++) {
var audio = audios[i];
audio.addEventListener('play', function() {
var iframes = document.getElementsByTagName('iframe');
for (var i = 0, len = iframes.length; i < len;i++) {
var iframe = iframes[i];
var src = iframe.src;
if (src.indexOf('player.vimeo.com') > -1) {
iframe.src = src + '&enablejsapi=1';
}
}
});
}
</script>
UPDATE: I got this to work BUT it doesn't pause the iframe video when the audio starts. The only thing that works is that when playing the audio, the video pauses. I need it both ways.
<script>
document.addEventListener('play', function(e) {
var audios = document.getElementsByTagName('audio');
var iframes = document.getElementsByTagName('iframe');
if (e.target.tagName === 'IFRAME') {
for (var i = 0, len = audios.length; i < len; i++) {
audios[i].pause();
}
} else if(e.target.tagName === 'AUDIO'){
for (var i = 0, len = iframes.length; i < len; i++) {
iframes[i].contentWindow.postMessage('{"method":"pause"}','*');
}
}
}, true);
</script>