I am personally going to be using Rust, but I would like to know what everyone else is using :)
I am gonna C, with lua for scripting events.
(with sdl and opengl)
EDIT : for people using java, it's not too hard to play sound so if you have too much time you can embed sounds.
Of course, sound like everything else has a licence, but you can find free sounds (CC0 and cc-by sounds) on opengameart.
But there is also bfxr (which sadly requires flash).
I don't know if I can post a link here. But you'll find it on google with this word. . Anyway, you can easily create sounds just by using the "random" button. It goes from "grab a coin in mario" (the sound) to "a sliding door opening" or "an alarm" etc.
And the website says: "You have full rights to all sounds made with bfxr, and are free to use them for any purposes, commercial or otherwise."
So, after a hard day of coding, you can still sit doing nothing but listening randomly generated sounds.
I think I remember you can export them to a standard sound format. And it may be worth it to pass them through audacity to clean them a bit.
In the description of bfxr it's said that it's based on sfxr, but it's a bit improved etc.
They don't hide that. And yes it's a really good tool. Actually, I tried to (and failed to) create a protocol like for midi, but using values of bfxr instead. If you already used sfxr, you probably noticed that it's values (ranging from 0 to 1, "min" to "max"). So, the description of a sound is pretty small (smaller than would be any mp3 file for example :D). A small sound unit, yet pretty rich and versatile.
What I wanted to do was a sound synthesizer that would perform the same task as bfxr (or sfxr). So somebody doing a game, for example, you just send a small sound unit (the values) to the synth and obtain the result.
And so every game (in c, c++, java, c#, go whatever) could have such sounds (because it's a protocol, there is nothing to link, it's a third party program).
I always found very weird to use mp3 (or other complexe audio format) for such sound effects.