I have a Dell Inspiron 1545 laptop that recently started making a strange sound on a pretty regular basis (about once a minute for half a second) when playing music (from any source... iTunes, Pandora, Zune). I would describe the sound as that glitchy sound you occasionally get if your computer gets too busy and temporarily doesn't allocate enough cycles to the sound card, and it has to catch up.
It's a laptop, so I can't swap out the sound card, but the problem persists with the latest driver from Dell as well as the latest driver directly from IDT. I reloaded Windows, and the problem persists, and also occurs with headphones plugged in. That would make me think the hardware itself is failing, but I plugged in a set of USB headphones and it does the same thing, although the glitch is that the audio "skips" for half a second or so about once a minute (at random) rather than making a glitchy sound like it does with the onboard speakers or headphones. A USB headset should be bypassing the onboard audio card and driver, so I am at a loss as to why this is happening.