First time I downloaded this set I was in my early 20s, and had an iBook G4 (size of screen doesn't matter, and the speakers were standard). I could hear them, PERFECTLY - I would CRINGE even because it isn't just a buzz, it's an annoying, high pitched buzz that physically pained me to hear.

Now that I'm almost 30, I thought I'd download it again to see if I could still. My computer is now a MAcBook Pro 13". I can still hear it, PERFECTLY, at the speakers being at half sound.

So... maybe you used the wrong mHz to make this set.

I did download the other set after reading comments here (and you're possibly like "BFD, dude") - but no matter if you got the sounds from the website, used your own time.. the sounds are first and foremost the property of Nintendo, hence the suggestion the other set's author made.