This would effectively do what it does in PB, adjust the pitch/frequency of the sound.
From a quick (two minutes) glance over the SoundJS documentation I didn't see a way to do it, but that was apparently version 1.0.0 so there could've been more developments recently
It would be great to see SB get full access to the power of WebAudio, it has absolutely amazing 3d audio, effects, etc etc.