a nearby piece of shit AT$T phone. They interfere with everything. even toasters. hell I hear that sound everywhere too, even on the intercom at grocery stores. cus some jack ass has a GSM phone laying near the intercom.



I have had the same experience, but out in a cabin many miles from any
electronic interference. Was like getting a message in Morse Code.
Didn't try to analyze it, figured the meaning would be made clear when it
needed to be made clear.