I read the manual (yeah, I know, I'm a geek) and on at least 5 or 10 occasions, it said "...if your car makes this sound...it's normal...".
Okay, I accept that, but as an owner of cars for the last 34 years, I know one of the best diagnostic tools is one's ears. After a while, you know a car's sounds and if you hear something different, you know that something isn't right.
With the TCH, every now and then there are certain sounds, which are, presumably, normal.
How does one know if there is a sound generated when something is wrong?
(I know there is the check engine light, but not every problem shows up there).

 

??????
That's why manual explains which sounds should be considered normal? Anything outside that would be a subject for further investigation? Also one would assume brand new car would be in good working order and only down the line, if there was something new and unusual one would investigate. Every car has different "normal sounds" and there is learning process. My old Honda Accord had electric radiator fan that could come on even after the engine was shutdown, so the manual had warning about that as being normal. Same with TCH. Off the top of my head and I never fully read manual, here are some differences: much louder wide open engine sound due to muffler bypass at high RPM's to lower backpressure, winning sound of electric motor during both breaking and acceleration, you could hear fuel pump when engine is off (in other cars engine overpowers that sound, but I still can't hear it anyway) and power breaks during initial pressure build up by electric motor, instead of vacuum from engine. Honestly except for electric motor sounds, which I think are pretty cool I can't hear anything else most of the time. Sounds normally associated with some type of trouble, like valve knocking, breaks squealing etc are pretty much the same as in any other car. Is there any sound in particular you worry about?

 

I think we need a DVD manual so that Toyota can store sound clips of what's normal.

 

LOL!
The other day I heard a hissing from the wheels and thought, "oh, that must be one of the normal noises", but a small voice in the back of my head said "what if it's not a normal sound?"
I know this was a silly topic, but I wonder about the 'normal noises'.