Cleaning up sound on Audio recording for court case

[RAMd®d]

It was actually a wire for a court case (prosecutor side) where there is a lot of clothing noise and some car/street noise.

A slight bunny trail- typically audio recordings aren't allowed in criminal proceedings (and maybe?) civil court as well, except for specific circumstances. Could you elaborate on the how and why this will be accepted as evidence?

Also, it seems to me that any editing, even "cleaning up" a recording may negatively effect it's evidentiary value. Are you familiar with similar situations.?
Inquiring minds and such...