Snes9x.com

it sounds the same when I put it in 16ms and 210ms

the sound buffer is a storage space for sound data before it's actually played. the reason for is to prevents skips or stuttering in the audio if something causes a tiny interruption in the generation of audio data - as long as the buffer isn't completely emptied, then there won't be any stuttering. if you're old enough to remember portable CD players, this is how they tolerated being jostled around.

the downside of a buffer is that all audio is delayed by the buffer length. if you wanted to demonstrate this to yourself, take a game where pressing a button causes a clear visual effect and clear audio effect - say Megaman X and the shot button. with different audio buffer lengths, you'd see that there's a longer delay between when you push the button (and see the shot onscreen) and when you hear the sound effect. with the CD player analogy, the downside is that delay between when you hit the "play" button and when it actually starts playing.

having a longer audio buffer is more likely to be helpful on:

• older/slower computers
• computers doing a lot of work in the background
• computers with poor-quality audio drivers