Comment 16 for bug 342946

@h3

I would suggest then that previously (pre 9.04) it was mobile phone based interference, but what you have now is a repeat of the bug the rest of us are reporting.

If the interference is like this

http://www.freesound.org/samplesViewSingle.php?id=41003

with or without a following continuous interference tone, it suggests phone based interference. It does not have to be obviously transiting data to do this, there are lots of passive actions a phone could be doing that communicate with a base station.