look, i think you guys are being a tad too over the top in this post.
i think the OP is just excited. some people just like to pamper their reptiles as they would a dog or cat. though a sound machine may not be beneficial, it may make the OP feel more relaxed knowing and thinking her cham is comfy while shes away.
i partially agree with Laurie, though a MistKing would be a great investment, you may not need one with only one or two chameleons. I'm not sure how many you have or how busy your schedual away from home is. i say just enjoy the chams you have, stay excited, but keep learning and know what nessesities are involved with having chameleons as pets or hobby animals. and know what is safe and beneficial to your chameleons health, i seen waterfall mentioned in this post....mine is a very nice decor in my room