help me diagnose sound (sound clip included)

[Xevuhtess77]

hey ive had a high pitched buzzing noise comign from my engine bay when my car hasnt warmed up. it slowly goes away after like 5 minutes of driving. im not sure whats causing it, and i havent felt any difference in my car, just the sound. i took a video and then took only the audio from it, for file size sake. the first part is me starting the car and then walking to the engine bay. the second part of it is me placing the camera on the cruise control box in the engine bay and then revving the engine a bit. the buzzing follows the engine as it revs, as you'll notice. whats causing this?

http://mercury.walagata.com/w/xevuhtess7/Camry.mp3

[coolchu001]

....hmmm thats probably the timing belt?....or maybe check around the timing belt to see if anything's rubbing against it? I do have a sound like that from my camry, but very subtle and its gone in a less than a minute...

[duggy]

sounds like your ac compressor or your power steering.

[Xevuhtess77]

if i had given you guys the whole vid, i pointed the camera at where i thought the noise is coming from. it sounds like its coming around the engine itself.... but its impossible to pinpoint. ill check my timing belt, though i dont think it's that.

where do i look to check the power steering and ac compressor?