I understand the need for these noisemakers, having been startled a few times by electric cars moving at walking speeds as without a noisemaker, they are effect

I understand the need for these noisemakers, having been startled a few times by electric cars moving at walking speeds as without a noisemaker, they are effectively silent. But these weird spaceship noises, I hate them, and for some reason, dogs seem the hate them too. So unnatural. I much prefer more typical noise like white noise, like a fan running. I think that studies have shown that white noise is particularly good for that purpose as the source can be located easily.