Here is a recording of my 2010 RX450h, purchased in Dec of 09. I am standing beside the front passenger side wheel, and I start talking at about 00:28 for comparison.
Hope this helps.
[oops - forgot to attach the file the first time around]
Thank you so much for making the recording. I really appreciate it. So it pretty much sounds like my car. I guess that is just how the Lexus Rx450h sounds. I think the sound from your car is more consistent than mine, but it is the same. I am really surprised the engine sounds like this. You would think that it would be quiet as this is a Lexus! Thanks again! -Pete