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Looks like I'm moving this month, so I have a bunch of paperwork to do at the city hall... And the way there from the station is infested with these things. All. Over. The. Place. Entire sides of buildings plastered with emitters. Can we please make this illegal already?pic.twitter.com/eOsrMwxYtA
Apparently (n=1) I can hear this crap well enough to nearly identify the note, even though it barely feels like a tone. I sang what I thought was the same thing and ended up at 292Hz. That's 6 octaves lower than 19kHz, off by about 29 cents.
Clearly you are not a sopranissimo.
Alot of info on the subject in this research paperhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786042/ …
(1) Hi. Yes we have quite a lot of info on this. I put together a series of papers for a special issue of Journal of the Acoustical Society of America on this. There are about a dozen paper listed on https://asa.scitation.org/topic/special-collections/uia2018?SeriesKey=jas … and you should be able to download them. If not...
Wow, i haven't been able to hear ultrasonic transducers or even tv flyback transformers for decades now, congrats on keeping your hearing
N= at least 2! I remember hearing this tone all over Tokyo last summer when I visited and it was quite uncomfortable. To the point where I’d actively move away from those emitters as I couldn’t focus while those things bombarded me.pic.twitter.com/kZPS9emXW3
Maybe they use as mosquitos repellent 
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