A friend of mine has sent me an MP3 file to process. After processing in WAV with Audition is there any point in saving as WAV or would MP3 be the same (ish) quality considering that the original was lossy in the first place ?
The file is of his children singing, quite hissy and there is handling noise.
Mp3 is ok as a final product. Especially if it's for home use, there's no use in keeping it wav.
If you would just convert an mp3 to wav and recode that back to mp3 right away, you will have a worse file than it was before, although it may be inaudible. I assume you processed the file and made it sound better than it did when you received it. Coding to mp3 will still loose some data, but it should be ok.
If you'd burn it to a cd, I would keep it a wav, there would be no use converting it to mp3 only to recreate a wav equivalent by burning it to cd. Also if it will be used as soundtrack for a video or something, keep it a wav, the video probably compresses it anyway later on in the process.
So my suggestion, if it's the end product: you could mp3 it (but use a decent bitrate).
If it's to be processed further, either by burning or syncing or whatever they'd want to use the audio for: wav it.
Thank you nemoDaedalus you confirmed what I had suspected.
I did an ABX test today using foobar 2000. There was a minimal discernible difference between the MP3 and WAV but not enough to have to burn to CD, so I can email it back to him rather than use the postal service.
Apparently he wants the file for posterity and to "embarrass the girls when they are older".