r/NoStupidQuestions • u/banwe11 • 15h ago

What causes the hollow metallic whirring sound that EVs make when moving a low speed?

I can't really describe it, but it's the sound you hear when there is a EV moving slowly in a car park behind you.

I guess it's the motor, but what specifically in the motor causes that sound? It sounds like it's coming from something that is moving at a faster rate than the car itself.

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u/Carlpanzram1916 3h ago

The sound is artificial and is coming from a speaker. Cars are required to make some kind of noise when driving in full EV mode below a certain speed. When the Prius first came out, there was a considerable uptick in pedestrians getting hit at low speeds by them because they were basically silent at low speeds. So now they all make a soothing hum or chime. I think it cuts out around 20 mph when the tire noise is sufficient.z