High frequency pitch sound

you must have dog ears.

 

What you are hearing most likely is the inverter. Its basically like a high frequency switching power supply on steroids. These switching supplies "chop" the output signal on and off very fast with high power semiconductors. The ratio of "on" time to "off" time allows a fairly precise control of output power as well as the AC sinewave generation. This is often done at kHz speeds, making it faintly audible. If you listen, you may also hear it during braking as the same thing happens with the regen system driving back through the inverter.

Here's a description of the basic idea if you're interested.
TMEIC GE e-news: Drive Time

Rob

 

Yeah Ive heard it during breaking. If Im walking down the sidewalk and I hear the sound I always know there is a hybrid approaching.

 

What I really hate is that god awful racket that comes from the front part of the car. Im not sure what it is but its in front of the dashboard and under the hood. God! I hate when I hear that sound!

 

remove it

 

I sit in my garage with driver's side window down and I can immediately hear a high pitched sound when I put it in reverse and let off the brake. Put the brake pedal down again and it goes away. Let off the brake and it comes back.

I think it's the electric motor ...but I don't know why it would make noises with the brake off yet not moving.

 

Isn't this the intentional sound put into all 2012 model years to give pedestrians the sound of something approaching?

 

It sounds like you're hearing the pedestrian warning system. Its especially loud when sitting in the garage with the window down. It should go away past 15MPH or so. Although somewhere around 10MPH, I cant really hear it anymore while inside the car.

This can be disconnected, removed, etc. There are instructions here somewhere. IIRC, Rebound had a nice walk-through with pictures.

 

What I meant was, the sound is present from 0-15MPH. And yes, the pedestrian warning system only makes a noise when your foot is off the brake. When your foot is on the brake, presumably while you're at 0 MPH in the garage, the noise goes away.

here's a video of it:

 

Ahh...thanks for that explanation. That makes sense.

I can't see any URL for a video. I've noticed before when people say "Heres a link, etc." I can't see it. Stupid computer ...of course it's not stupid operator.

 

so that explains the loud whirls... never heard on my stealthy first gen Highlander hybrid.

maybe this pedestrian warning switching on and off explains that faint click I hear when the brake pedal is depressed at slow speeds (no radio or ambient noise in the cabin of course)?

 

Personally I feel it's best to leave the speaker hooked up, I don't want to see a white Prius turn "red".

 

fud

 

That's what I thought because mine does not make any noise when standing still in EV but makes a Jetson like noise when it starts moving at low speeds.

 

There is another high pitch noise besides the pedestrian warning. And a drill is a great example, because mechanically its very similar. An electric motor spinning an axel.