Are you playing from an auxiliary cord? Sometimes if im charging my phone and playing music off of it in my 09 silvrerado it makes a little winding sound too but only when i charge and play never any other time

I too have seen this scenario in my 07...

Alright everyone, I had this exact same problem on my 08 suburban. I noticed it within the 30 day used car warranty and the dealer was nice enough to take care of it for me. Anyway, after checking the grounds and speaker connections, they thought it was the amp, but it wasn't. They ended up pulled the rear radio out of another Suburban on the lot and swapping it with mine. Sure enough the noise is no longer in mine, but was in the other Suburban when they plugged my rear radio into it.

For those of you with this same problem, I hope this helps.

I have found that I can turn my speed volume off I don't have the problem anymore. :)

I'm feeling affirmed to have found this thread. I've been dealing with the increasing noise (frequency and level) for over three years. My dealer claims they have no reports nationally of anything similar. The vehicle has been in MANY times, and they usually claim they cannot hear the problem. Had the amp replaced; no noise for three weeks; used OnStar to make a call and the noise returnedd. Had the amp removed; consulted the dealer and they had no other recommendations, so they also replaced the amp. The noise resumed within a day. Original amp back in. The noise grows in frequency and level as time goes on. It's like a spaceship whirring up to take off, with usage of radio or blinker, or when door is opened while engine is running. HELP ... dealer can't!!!

been getting this too. good thread. useful info.

Try replacing the rear radio. Worked for me.

I just got an 08 burb and have the same problem... Is there any place I can get the part number for the rear head unit? I don't want to pull it and then wait for parts... Am fairly certain it is the culprit because when I get the whine if I tap the unit it goes away...

Thanks joeincharlotte, replaced the rear unit and the horrid noise is gone!

Glad it worked!