I'm not sure that this question is appropriate here. There's a good chance it's too opinion-based. If that's the case, I'm sorry.
I was sat in a research seminar recently and wondered whether it'd be tacky if the speaker made the mathematics in his presentation somehow audible (in a non-trivial sense).
I've been tempted to write a programme or something ever since, that'd attach all the bells & whistles to a given symbol-heavy proof. I picture something like a beamer presentation where each relevant slide makes a noise once it's called, so that any patterns in the equations (or whatever) really leap out at the audience. If used sparingly and with taste, I suppose it could be quite effective.
$\color{red}{\text{The }}\color{green}{\text{use }}\color{blue}{\text{of }}\color{magenta}{\text{colour }}$, $\Large{\text{font sizes}}$, italics, etc., are certainly effective on me, so why not sound?
In studying Mathematics alone, too, especially with dry, dense proofs, I have tried making small noises. It is a bit silly, yeah, but the odd "pop" for certain substitutions can be really handy. If anything, it makes things less dry . . .
So here's my question:
How best does one use sound in the study and/or presentation of Mathematics?
Again, I'm sorry if this is too opinion-based.
My mentor, a delightfully eccentric mathematician, uses sounds quite often. I remember, when he introduced difference sets to a bunch of people, he gave one of the defining equations of algebraic design theory by making a little popping noise with his tongue after he was finished writing it on the blackboard. In the next lecture, when he wanted his students to remember the equation, he allowed about 30 seconds of silence before he made the popping noise. At least a dozen hands shot up, whereas before this sound, there was only one (me). I consider this effective.
I also remember seeing a colloquium talk where the speaker made annoying sounds that contributed nothing. He did this incessantly, throughout the entire talk. I consider this ineffective.
Thus, my experience-based guidelines might look like this: