"D" <tarb@bk.ru> wrote in message
news:1192480473.647816.62910@z24g2000prh.googlegro ups.com...
> Hello!
> A background (about 50hz) rumble appears in a sound from microphone.
> Windows XP SP2.
> I tried two headsets (which surely are good). The rumble decreases if
> I touch the computer case. I checked the inside of the case, did not
> find any improper contacts. The sound card is Creative sound blaster
> live ct4830. I tried the latest Microsoft and Creative drivers. The
> Creative driver does not output sound from microphone to speakers at
> the same time, but only from a recording from the microphone. How to
> prevent the rumble?

By "rumble", do you mean hum? Where are you located? What's the line
frequency where you live?

If the "rumble" isn't hum, then it could be a mechanical resonance of the
computer's case with one of the fans. One way to reduce this is to put
adhesive pads on the metal case; they're usually sold for dampening rattles
in cars.

Peace,
Paul