background noise on recordings

[dnmbc]

Hi
(A) I've been recording telephone interviews for a radio station I work for as a freelancer. For some reason, there always seems to be some kind of humming associated with those clips. The humming doesn't show up when I interview people with a recorder and microphone so I assume it has something to do with the telephone/computer/audacity. But I can't seem to solve the problem.
(B) For some reason, my computer won't let me save audacity files as MP3 only as WAV. Hopefully you have some advice about that too.

[waxcylinder]

A) the hum is likely to be mains hum possibly caused by an earth loop or earthing fault - is it 50Hz/60Hz (depending on geographic location).

B) In order to Export to MP3 you need to have the LAME software installed - do you have this? Audacity cannot distribute LAME with Audacity due to licensing restrings.

BTW: don't get confused with SAVE in Audacity and EXPORT - Save creates Audacity projects which are complex and fragile little beasts - Export creates transportable, usable music files.

WC