I searched this group for "GSM interference" within Google Groups and found nothing, so this may be "something new" for some readers.
Yesterday, after a lunch meeting with a Nokia guru, we adjourned to my home office to review some matters and, within seconds of booting one of my systems, a "noise problem" that has sort-of bugged me for a year evidenced itself. The Nokia guru instantly stated that sound was GSM interference.
I was both relieved and puzzled; my cell phone is a Motorola RAZR V3.
Relieved because I now knew for certain the "sound" wasn't a virus or other malware. My concern began last year when I first heard a "dit-dit-dit dit-dit-dit dit-dit-dit dit-dit-dit" and thought some malware had somehow arrived on my system. Using Process Explorer and several AV scans revealed nothing, and since the sound only appeared no more than once or twice every day and then only for a second or two, I tolerated it.
Puzzled because the Nokia guru stated this was a common and known problem. So bad that in fact at Nokia HQ they turn off all the Polycomm conference room phones when having a meeting; he stated also that Polycomm phones are the worst offender in this regards.
Later I did a normal Google search using "GSM interference" and, WHOA!, 1000s of pages of hits. Many affecting pro audio studios' sound mixing consoles. Long story short, this "GSM inteference" appears to be a widespread problem and it's only with GSM, not any of the other cell phone or PDA technologies.
To hear the sound I'm talking about (just a few seconds each):
and
Here's one explanation for the sound which I found here:
" If you ever do any type of recording or use devices with " audio components the day will come where you hear this " awful racket. Some call it buzz, some say it sounds like " a fax machine and others call it things I won't print here. " It sounds like this. What is that noise? It's a BlackBerry® " type device or an iPhone (GSM) checking in with master " control. It is the sound of digital data being transmitted. " At very low levels (when the phone is some distance away), " the "buzz" may not be heard, but your audio will sound like " there's some "fuzz" on it. The guilty device can be anywhere " in the room, possibly passing in the hallway or all the way " across the lobby. It is imperative that you monitor your " recording because you never know when the problem will occur. " " What can you do about it? " Have the device turned OFF. Not on silent or vibrate but OFF. " If the device must remain on, then create as much distance " between the device and the audio equipment. The greater the " distance, the softer the interference. " " Cellular phones (GSM , TDMA), iPhones, or a BlackBerry® and " the like send out strong electromagnetic (EM) pulses as data " messages. They check in with the network for messages and to " report their location. CDMA phones and BlackBerry® devices " (Verizon) usually do NOT cause any problems.
So, how did GSM ever get FCC approval given this very widespread RFI/EMI problem?