They actually do have ears but they are holes just below the skin and they can hear a very limited range - so play whatever you like! I sometimes go into my herp room, which is also my office, and put on my red light to spy on my geckos. Luna almost always wakes up.
If I will be on my computer past their bedtime I simply put towels over everyone's enclosure. This helps maintain a little warmth and humidity, too. I take it off when I leave the room so they don't interfere when the lights come on in the morning.
lele & Luna 
>>Ok my chameleon goes to bed around 8pm (her light is automatic 8am to 8pm) and her cage is in my room. Well *I* dont go to bed at 8.
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>>How hard do chameleons sleep? Does the glow from my monitor keep her up? What about a little music? They dont hear to good right?
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>>Basically i want to keep from bugging the heck out of my chameleon by staying up later than she is. Do you think she minds?