I'm using SugarCube format, but I think what I used would still work for you (I am also a beginner).
I put this into my javascript section:
$(document.body).on("mouseenter", ".mickey", function () {
$("<audio></audio>").attr({
src : "the url for my sound",
autoplay : "autoplay"
});
});
And in the passage I put:
<span class="mickey">[img[the url for my image][mickey]]</span>
I think there is a bit of delay which there may be a way to fix. I forget where I got this code, probably from a google search. You can just copy and paste it from here and add in the urls for your image and sound (I'm guessing you want the sound to play when you hover over a certain image). You can change the class name "mickey" to whatever you want, so long as you make it the same in the passage and in the javascript section.