I’m not in the USA, so there very well could be a different scheme going.
But anyway before a cell phone call comes in speakers go silent and issue a series of beeps and a second or two later a cell phone gets a call.
This even happens in cars, beeps then someone in the car gets a call on their cell.
The hell? What is this?
Are you talking about when it’s connected to via bluetooth to your car?
Mine doesn’t do that, it just rings, though the music does cut out and in my previous car (Honda Insight) the AC/Heater fan would go to a lower speed*, which was nice 'cept it would speed right back up when I answered the call so someone didn’t program that right.
Anyways, that’s just the way your car, assuming that’s what you’re asking about, is set up. It’s not universal. Neither of my bluetooth Hondas did that and I set up my sister’s Ford the other day and I don’t think it did it.
What kind of car do you have?
*That was always weird “Hey, why’d my AC turn off, oh, wait, my phone is about to ring”.
The radio conversation between the phone and the cell tower causes that ‘blip-blip-dit’ interference on many devices that have an audio amplifier in them - especially when the antenna power is high, which (amongst other contexts) happens when the phone responds to the tower to receive a call or message.
In English, the conversation would look something like this:
Tower: Phone number X! You there? Where the hell are you?
Phone: Here I am! HERE I AM!
Tower: I have a call for you
Phone: OK
Tower: Here you go
<call connection commences>
(the graped part being the point at which the interference occurs)
Another thing, do your speakers ‘ring’? In all my cars, when I’m connected to the car and I get a call, the car speakers ring but the phone doesn’t. If your car speakers don’t ring, that could be their version of ringing.
Huh well I can’t speak to others cell phones but I use a bluetooth free variety that would have been top of the line in '98 and it happens on all speakers, TV, PC, radio, car you name it.
No my speakers don’t ring, just go quiet and BEEP BEEP BEEP and a few seconds later cell phone rings.
Ahhh, that’s just what Mangetout was talking about then. That weird interference sound. Mostly noticed in the late 90’s with computer speakers.
This is most likely the “GSM buzz.” There are numerous articles on it; here’s one with pretty pictures and an audio example.
All radio technologies can cause interference, but GSM was particularly prone due to various choices they made, including a “hello” signal (like Mangetout described) that was very distinctive.
It’s not so common any more in places with 3G/4G, since these technologies use radio systems that are less prone to it.
GSM is the culprit. Interferes with anything that makes noise.
Back when I was making cell phones, we used to amuse ourselves occasionally by guessing what type of phone people had based on the pattern of chirps the interference caused. GSM sounds different than CDMA, for instance.
BTW, this is the underlying reason for being asked to turn off your phone on airplanes and near sensitive life support equipment. (Yes, things can be shielded to prevent problems, and it may be questionable if the caution is needed any more. I didn’t bring it up for that discussion…just the background)