What do professionals use to clean up audio?

What audio software do professionals use for restoration of old recordings after ripping it to electronic format?

What about audio techs hired or employed by law enforcement, FBI, etc? I would imagine need to often clean up low quality recordings off wire taps and such. Or to do the type of audio analysis you see on TV where a suspects calls in and they isolate background sounds to try to figure out the location?

I several wav-files I’d like to clean up. One is of a very old recording of my late grandfather giving a speech, but it’s full of noise, and has that echo characteristic you may have heard on old recordings - I think it’s the only recording of him and I wanted to clean it up for my father. The other two files are from 10-15 year old VHS tapes. The originals weren’t professionally shot or editted, so low quality again, but I’d like to do basic cleanup on both the video and audio (either simultaneously or separately) before converting them to avi-files to share with friends. I don’t have access to the originals, so just working with wav-files here.

I believe you are watching too much TV, but to your problem.
There are basic software that will clean some pops and hiss by preset settings.
There is also one, Sound Forge, that will let you clean up file pretty good, specially one with your grandpa.
Not sure how much are you wiling to spend.
You can also check Audacity
If you want to go FBI way, you should ask for a loan first.