uhm..unsure what you're doin. If it is for an addon i can't help you as i have no clue about addon making. If it's just for simple ingame music and/or sound fx, as far as i know a lower quality shouldn't affect the playability.
Just as basic info about music files: What does 44.1kHz and 16 bit mean?
Well, basically the sample rate (kHz) defines the highest frequency which can be reproduced. Just half the given frequency (i.e. 44100Hz / 2 = 22050Hz = 22.05kHz). The Human ear technically can hear up to 16000Hz, everything above goes under "psychoacoustics"...some say you don't hear it, but you would remark the absence of it..(i should learn better english...)...i hope you see what i mean.
The Bitrate (16bit) actually tells us the accuracy of the sampling process. The lower you go with, the more you risk "digital noise" which is generally very disharmonic (as analog noise can be very harmonic and is often a wanted side effect of analog tubes).
However, reducing sample rate and reducing bitrate can reduce the file size. But it is always a search for compromises...better quality but higher file size or smaller file but lower quality...find out what fits your own requests.
I suggest, if you have more than 1 audio file, use always same settings for all files in the same mission, as some players m8 be irritated to have changing quality into the music. ;D