How can I apply an effect to a sound to simulate hearing it underwater?

Question

I'm using XNA 4.0 and trying to reproduce an "underwater effect" for every sound played.

How can I apply an effect to a sound, and what effect should I use to make it sound like as if the player is underwater while hearing it?

Answer 1

DynamicSoundEfectInstance might be a good start.

Load the sound into a buffer from a file, then apply a custom low-pass filter to it.

See this question for more detailed information on adjusting audio in XNA.