posted on Nov, 17 2007 @ 04:13 PM
Clay hit on part of it with the cell phone interference bit, This happens all the time where I work, someone sets the phone down next to a computer
speaker and it starts clicking and buzzing away when it rings or the phone connects to the system.
Most phones I've seen will only affect devices from three feet or less though so I'm curious about the random interference you are experiencing.
The name for the phenomenon is Electromagnetic interference
is a site for tracing where exactly the problem is coming from. Although
I'm not sure it will help with the clock radio, are you listening to the radio when these sounds come in? If so you could try listening on another
device like a Walkman or something and see if the interference is mutual on all devices.
There are all kinds of signals around us everyday that can cause undesirable noises in amplified gear, I've worked in A/V production for about 9
years now and this is one of my least favorite things to troubleshoot, in audio production situations it's almost always a bad cable, bad shielding,
or bad grounding. Sorry I can't be more help with household objects, I only experience this type of thing when there are cell phones present in my
house, but reading those two sites and digging around a bit more may give you a bit more help in determining exactly where the problem is coming from.
Best of luck! I'm always amazed that people are allowed to sell devices that are obviously interfering with others...
Edit to add: in regards to the PA at work, if someone left there cell phone next to the amp that feeds those speakers it will cause the same sound,
usually you have to be next to the amplifier bit to get the interference. If you stand next to an unpowered speaker and use your cell, there won't be
a problem, but if the speaker has an amp built in you will.
[edit on 11/17/2007 by thebeard]