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When I first got a cell phone (an early Sidekick), a new noise entered my life. When I put on my big crazy headphones while the phone was in my shirt pocket, I’d hear a very distinctive “blip ba da blip ba da blip ba da buzzzzzzz” noise right before my phone rang, so loud that I’d have to wrench the headphones from my poor ears — which was handy, because then I’d hear the phone ringing. It took me a long time to figure out that this noise was coming from the phone, because I’m kind of slow. I also heard it when the phone was near mostly any speakers (even my TV set), including when I received text messages or used other data features on the phone. I recently saw a discussion of these noises on a fellow _flosser’s blog post. So what causes this noise?
Basically, it’s the cell phone talking to the tower, and nearby speakers picking up that radio transmission. There are several Metafilter articles on the subject, which make for good background reading. The best technical explanation I’ve seen of the phenonemon I’ve seen is on this WiFi-Forum post:
The type of interference can occur if the following things happen
together:
1) a pulsing radio transmitter,
2) with relatively strong power,
3) in very close proximity,
4) to a non-linear circuit element.The non-linear circuit element is usually some sort of solid state
device such as a transistor or diode. If the non-linear element is
subjected to a strong pulsing radio signal, it will act as a rectifier
and “detect” the pulsating waveform, i.e., convert the pulsations from
a radio frequency to an audio frequency (if the pulsation rate is in
the pass-band of audio frequencies.) For example, a hearing aid
consists of a microphone, an audio amplifier and a small speaker. If
a strong pulsating radio signal impinges upon the first transistor
amplifier stage, the transistor will be driven into its non-linear
range and detect the pulsations. If the pulsation rate is in the
audio frequency range, the rest of the hearing aid amplifier will
amplify this and deliver it to the speaker, to the great annoyance of
the hearing aid wearer.
This annoyance is endemic to certain digital cellular technologies (including ones used in music devices like the iPhone, eek). The only ways I’ve found to mitigate the sound are: move the phone and the speakers father apart (this only seems to reduce the noise a bit…), turn off the cellular portion of the phone (the iPhone, for example, has an “airplane mode” that makes it practical to play music in the car — without this turned on, the car sounds like it’s being ripped apart by buzz-saws), or introduce electromagnetic shielding (good luck building your Faraday cage).
If you’ve got tips on how to reduce this noise, or a story of how annoying it is, please share in the comments.
Ah, finally…an explanation. Everytime I dial my phone in the car, the stereo makes the same noise.
posted by Zane on 12-13-2007 at 9:48 am
I find a tin foil hat works EXCEEDINGLY well. Ah Thenk Yoo.
Pssst, they’re behind you……
posted by Chris Murley on 12-13-2007 at 10:09 am
I’ve just learned to live with the stupid noise.
posted by paperback writer on 12-13-2007 at 10:31 am
Can anyone explain this? I’ve noticed the same phenomenon when my own cell phone is in the vicinity of my home theater speakers. But here’s the crazy part: one night I was watching a movie in which, in one particular scene, a cell phone rings. My speakers made that sound just before the cell phone rang in the movie! I couldn’t believe, so I rewound it and watched it a few more times, and it happened every time. It doesn’t seem to fit the explanation above (since the phone in the movie couldn’t have been projecting radio waves into my room), but it happened.
posted by Craig on 12-13-2007 at 10:41 am
Since my work blocks all of my personal email and facebook, I use texting a lot to keep in touch with my friends. However, every time I get a message the woman’s speakers at the desk next to mine makes that crazy noise! I had figured out long ago that it was from my incoming messages, but I can’t tell anyone or they won’t let me bring my personal cell phone to work! So, I have to hear her complain about the noise everytime and even get into debates sometimes, while I slunk behind my desk! Whoops!
posted by Kate on 12-13-2007 at 11:06 am
I always found that VZ CDMA phones didn’t do this much. The GSM and EDGE phones and even TDMA Cingular/ATT phones are so bad I figured they had paid someone off at the FCC. Seem to interphere with anything that has a speaker, not mention making radar detectors freak out.
posted by John Jaser on 12-13-2007 at 11:11 am
it happens with our baby monitor too. only when the cell phone is charging though. when i plug the cell phone in on another counter in my small kitchen, the baby monitor starts buzzing really loudly. if i put my hand next to the phone the buzzing lessens though. i always just figured it was part of the fcc compliance statement on the monitor that says it will accept interference from outside sources even if it disrupts normal use. i have found this statement on a lot of my son’s musical toys, too.
posted by lindsay m on 12-13-2007 at 11:11 am
This happens to some of my peeps phones at work, especially with the cb radios. But, it only seems to happen with att/cingular phones, it doesn’t happen with my sprint phone. Go figure!
posted by Eddie on 12-13-2007 at 12:19 pm
At work, I keep my cell on my desk beside my monitor and, even though the phone is on vibrate, I can literally see the phone “ring” on my computer monitor, since it disrupts the screen.
It also, incidentally, disrupts my desk phone a little bit. I’ll be on the landline and hear loud static just before my cell rings.
posted by Jennifer on 12-13-2007 at 12:26 pm
I used to think my car was just “awesome” because the speakers would blip a bit before my phone rang, it was nice because it was before crazy ring tones, and I couldn’t hear my phone ring over the music if it didn’t do that. Then I switched to Verizon and it stopped. Oh well, I still think my piece of junk car is awesome a little.
posted by Kelly J on 12-13-2007 at 12:48 pm
I find it quite fun to put the earpiece of my phone over the pickups of my electric guitar and start pressing buttons. Needless to say, the interference creates some interesting tones.
posted by Jordan on 12-13-2007 at 1:58 pm
I used to have this a lot when I was in construction. We all had the Nextel phones and the speakers in the van would make a horrible noise everyso often, even when the phone wasnt ringing, but especially when it did. Also, it was always the same loud volume no matter what the radio volume was set to, unless it was completely off.
posted by bo on 12-13-2007 at 3:29 pm
This comes in very handy at work. I work in a building where we do not get reception (security reasons) I set my phone next to my computer speakers and voila! I do not recieve the call, but I know when someone has called, and can use the landline to check messages!
It has also helped me to convince my children that I am psychic in the car, I pick up the phone before it rings! they don’t seem to catch on to the speaker buzz first…
posted by TracyB on 12-13-2007 at 4:24 pm
Oih!
Yeah, I know that buzz all too well. One of my jobs in college was working as an auditorium/sound technician. If the presenter/speaker had a cell phone on them I would tell them constantly to turn it off. If they didn’t it would make the auditorium sound system get “fuzzy” while their phone was ringing. Even the staffers cell phones would affect our own sound equipment in the booth. Eventually I figured out that only the Cingular phones were setting it off while my Sprint phone didn’t affect anything.
Needless to say I was the cell phone nazi once I figured out what was causing the audio problems. It was compounded by the fact that all of our professors/special guests carried the “Crackberries” around.
Uggg…, I couldn’t begin to tell you how many times I’ve defended my sound teching because some dolt of a “smart guy” didn’t listen to my instructions. When the buzz sound gets blared through our speakers they would always look up at the booth and I would just shoot them the evil glare. I KNEW it was them, but once it happened it was too late. My boss comended me for keeping my calm each time though, since I wasn’t of the same paygrade as those overpaid know-it-alls. I swear there is some sort of inverse correlation between education/success level and their ability to listen to instructions.
posted by Allen on 12-13-2007 at 11:52 pm
I have the same computer monitor problem as Jennifer. About 10 seconds before my cell goes off, for a call or text my monitor will have lines going across the screen. It also does it when I am sending a text or speaking on the phone while sitting at my desk.
posted by Christian on 12-14-2007 at 1:07 am
True story:
It’s history class in India’s premier law university. Cell phones are banned in class. In the middle of class, a friend’s phone starts ringing. The teacher asks him to move to a seat closer to front of the class (and closer to her) as he was “disturbing the class”, while he protests that he didn’t have his phone with him.
He cleverly puts his phone on silent before moving up front. Or at least he thought that was very clever. The lecture continues, and suddenly, beep beep—beep beep, the loudspeaker system that the teacher’s using starts catching a mobile phone’s signal. All eyes turn to my friend who’s the only one close enough to the microphone system. He feigns innocence. Two minutes later, there’s interfence again! Finally, he reaches into his pocket and puts the damn thing off!
There’s an important lesson to be learnt in that story… but I was laughing too loud when this happened in class to notice what it was.
posted by Pranesh on 12-14-2007 at 3:00 pm
Hey!
I always have this problem. I am with Rogers Canada, New Brunswick, and weather im at school, home or in the car, I ALWAYS hear that effin annoying noise. I’m sitting at my computer desk and my phone will be at leat 3 feet away from my monitor and speakers, then about 2-3 seconds before my phone rings, i hear it. Sometimes, it scares the crap out of me.
I was in my driving instructors car one day and I had put my phone in the compartment beside the stereo and the noise went off on its occaisonal annoyance, aha. I said to my instructor “I hate it when it does that”
and he says ” You know why? Because the magnet in your phone is too close to the electrical component!” I thought to myself, “Umm.. okay?” Because I knew that it had NOTHING to do with a “Magnet” in my cell phone? why would there be? to make it a paper weight? haha. Then he says “I have 26 certifications under my belt, I know all about this stuff!”
Alright buddy? Whatever you say?
posted by Andrew on 12-20-2007 at 8:48 am
Imagine how easy it is for the government to pick those signals out of the air to listen in on us!
posted by JAGX on 12-29-2007 at 7:50 pm
I have the same problem with my IPhone and my Miata speakers - drives me crazy!! would love to hear my Itunes without all that noise. I was told that the reason why I get that is because my speakers are not shielded. I do not have that problem on my Honda CRV
posted by Fernando on 1-18-2008 at 9:06 pm
my speakers on my computer do the same noise…but it happens when im not recieving a call or sms though, whys this?
posted by mike on 1-20-2008 at 9:24 am
Mike - supposedly this happens whenever phones make any kind of data connection (including things like checking whether you have voicemail), though I don’t know the details. I know my iPhone periodically makes blips and buzzes even when I’m not receiving anything obvious. I guess it’s just checking with the cell tower to see what’s new? :)
posted by Higgins on 1-20-2008 at 2:57 pm
Today after my favorite song was interrupted again I decided this noise for the last 2 weeks is not cool anymore, so I went on a mission to figure this out. Wow what a coincidence, i just got an iPhone, so BOOM there’s the cause…and…here’s a solution I found after visiting this site, I have not tested it, but hopefully it will work.
www.maclife.com/article/iphone_buzz_kill
posted by Jim on 2-20-2008 at 5:59 pm