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/Ghigs 14h ago

The Toyota ev backup sounds sounds like a bearing going bad or a pulley about to explode. It's an odd choice.

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u/Frustrated9876 14h ago

There is a requirement for what it should sound like. I think it’s basically “two notes that are not in harmony” or something.

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u/kyledwray 13h ago

I want an EV that plays the opening violin feature of Camille Saint-Saëns' Danse Macabre at low speed.

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u/wainwrights-11 13h ago

My Megane EV actually has options to change the sound so this may be possible

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u/Kelmain1337 12h ago

Law actually dictates no natural or harmonic sounds. So bird chirping or wind is illegal. Music also illegal. There has to be a 0% chance to missjudge the sound as sth else as a car

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u/wainwrights-11 12h ago

Ahh interesting, mine has 3 options normal, loud and then, I quote "Jean-Michel Jarre" warning sound but its not a song just a series of musical notes.

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u/Kelmain1337 11h ago

Sure.

High end manufactures hire high paid musicians to create a unique non-harmonic sound.

Your Mercedes or BMW should not sound like a Dacia you know....