I came across some of these in Tokyo recently as well. Super annoying, and I'm 40. I thought I'd be immune by now. I assumed they were intended to drive away cats or rats or mosquitos.
Can't speak for Tokyo, but there are streets in my American suburban neighborhood I avoid because of (presumably) animal-deterrent noises. I'm also 40, and surprisingly can still hear them - and an audiologist had my ears tested last month, and said my hearing is excellent for my age.
Which is a bummer when I have to cycle around several blocks to avoid hearing the squeaks that are physically painful to my ears.
In my experience those regulations are only ever used to shut down parties with loud music. If it's any sort of industrial or non-obvious noise, good luck getting people to care about it. I have bad memories of complaining in an online community about the extremely loud safety beeps from construction vehicles operating next to my home and being told I was a monster because I must want children/workers to die - and that was a sound whose mere existence didn't need to be explained.
Yeah, maybe. But the hassle of trying to convince the town this house is in - which isn't my town - to do something about it is significantly more difficult than just riding my bike around the place.
I've always wondered about that. I'm also bothered when walking around Tokyo (it's very prevalent in Ginza for some reason). I've also seen it in other cities in Japan but I've never had that issue in other cities in Asia (Hong Kong, Shanghai, Bangkok, etc..)
I'm 40 too but as a kid, I was very bothered by the high pitch wine of the tv turning on, so I'm guessing I've always been rather sensitive.
