I've just seen it mentioned in the forums, just like elevation causes buzzing; e.g, LivSimple:
Hi! i am REALLY thinking about getting this set. Do you have this plasma plugged into the wall or is it plugged into a line conditioner. It could be noise introduced into the set from being plugged into the wall. I would try hooking it up to a line conditioning power center from Monster or Panamax. I have my entire home theater hooked up to a panamax conditioner and it does make a huge difference in the performance of my home theater.( It protects your equipment from power surge also) Get one!
But here are a few sources:
By searching, another solution via turning off the set's audio:
Also of note, I keep the volume at 0 on mine since my Onkyo TX-705 runs audio for everything through my 7.1 system. In my experience most TVs are smart enough to turn off their audio amplification circuit when set to 0, which eliminates two more possible sources of buzzing (both the amplification circuit itself, and buzzing sounds that could be playing through the speakers). It is trivial to test this in a quiet room by switching between volume levels 0 and 1 to see if that changes things and switching between MUTE and 0, and MUTE and 1. I'll run this on my Samsung at some point and post back if I find anything interesting
This post by Randy Walters of AVSFORUM: Humming buzzing noise from your plasma tv?? How loud?
If you can hear any buzzing from more than a few feet then the TV is defective and needs to be replaced. Buzzing is a common defect among plasma TVs regardless of brand. It has nothing to do with the plasma cells working; usually it's a defective board or a power supply problem or something like that.
My new Panny PZ700U is virtually silent at 2 feet away, even at 4 in the morning in a completely silent room. My older PX50U is silent at 3 feet away, and that's after it's gotten louder over the past two years. I consider anything worse than my experience to be abnormal and unacceptable.
Have it exchanged for a good one
Makes sense to me because most plasma due not buzz; my Panasonic Plasma has ZERO buzz.