It is either a GSM (Cingular, Tmobile Suncom etc.) the amplifier if
detecting the rf signal which is a pulsed signal. It is the phone
"checking in" with the base station,
There is no "usable" information being transmited (other then to the phone"
Frank

Mike Muderick wrote:

If I leave my cell phone near my computer speakers I will hear occasional
buzzing, clicking, etc. Before the phone begins to ring, I hear a
dah..dah.daahhhhh. I know this is RF interference being picked up by the
amplifier in the speaker. If one were to record this sound with a
microphone at 11 or 22Khz, would it be possible to obtain any information
(usable signal) from the recorded audio?
Thanks,