Sonic Devices Play High-Pitched Noises to Repel Teens | Hacker News Reader

Sonic Devices Play High-Pitched Noises to Repel Teens

npr.org

33 pointstomcam41 comments

I am always so surprised and appalled that these things are still legal. Can you imagine the reaction if they were designed to only hurt pretty much any other demographic other than young people?

I wonder how this makes by 1 year old feel? I have no idea, he probably throws a fit, and nothing I can do will calm him down. :thumbs_up:

It’s fundamentally an attack on public space and should be illegal. I’m sitting in a small public parkette right now within earshot of an establishment that has one of these things running 24/7. I don’t even know which one as I can’t locate the precise source of the sound. It emits a high pitched whining noise for about 5 seconds, at which point the frequency rapidly increases until it ends in a zap, followed by about 2 seconds of silence. This differential makes it impossible to ignore. It even permeates headphones. I like eating lunch here, as it’s close to my office and a nice space, but I often leave irrationally angry after being unable to relax in the midst of this omnipresent noise.

Sadly there doesn’t seem to be anything I can do about it.

They are easy to locate. The sound can't pass through your hand and doesn't diffract much, so move your hand around at arms length till you can't hear it anymore in one ear, and that's the direction it's in.

Normally they're metal boxes with a grille on the front mounted above head height (because otherwise some teen would put gum in the grille to stop the sound getting out)

I keep hearing similar high pitched sounds in Tokyo in front of some stores as well, so the statement that only people up to 25 years old can hear it sounds incorrect.

The Mosquito youth repellent has even won an Ig Nobel prize: https://www.theguardian.com/uk/2006/oct/06/science.higheredu...

I think this fits the general trend of making urban architecture more and more hostile to the public.

Ultrasonic jewelry cleaning baths, these sonic youth deterrents, and a few other super high pitched sounds give me instant splitting headaches and I'm 28. Strangely I have terrible hearing otherwise and have to ask people to repeat themselves a lot.

I was in a similar position for years and got a hearing test. Turns out I have a sensory processing disorder that I got help for.

I’ve been told the ones in Tokyo are to repel rats and other (non human) pests, but no clue how legit that is.

As part of the affected age group, it sounds a lot like the high-frequency sound of a CRT monitor / old arcade machine (that older people cannot hear apparently), which is very much not pleasing. I can't imagine having to deal with that all night long.

When I was younger, I thought for sure I had a sixth sense for detecting when the TV was on. Strangely, it didn't really seem like a sound to me. More like something inside your head.

Unfortunately, my super power didn't pan out to be all that unique ... or useful.

I had the same super power! (And between you and me, I can also time travel, but only in a forward direction one second at a time).

And the longer you wait in the time tube, the further you go.

These have been around for quite some time. I remember encountering them in Japan about 13 years ago. It was in a fancy store in Tokyo, next to the Palace. As soon as I entered, my 30 year old ears alerted me that they hadn’t died off at 25 as planned. The one clerk in the store couldn’t turn it off and apologized profusely. I decided to have fun, and in my broken Japanese, accused her of having a device to ward off gaijin. She denied it profusely as I walked out, laughing... on to the next store.

Part of the reason they installed these devices is in part to reduce vandalism, but I can’t imagine any better motivation for vandalism than an extremely annoying sound coupled with moral justification provided by clear discrimination. They’re just asking for these devices to be destroyed.

I can understand the motivation, legality aside, but the implementation seems irresponsible to me. A device like that will very likely annoy, if not anger, dogs at distance. My old cats could hear two rooms away a 40 KHz signal played by a piezo transducer directly connected to a function generator with no amplification in between. An old ultrasound TV remote had the same effect. And cats hearing although better than ours is less sensitive than dogs'. I can't imagine what level of discomfort that device could put on cats, dogs, bats and other animals.

In Australia they play classical music through the sound system at train stations which has seen success in dissuading teens from congregating there.

Apparently the kids aren't into ol' Bazza... http://www.stuff.co.nz/oddstuff/268922/Britain-looks-at-Mani...

I seem to remember this effect being co-opted by teens to turn the tables. Use it as a text notification sound on your phone and you can text back and forth in class without alerting the teacher.

Such a backwards way of thinking. The youth want to be in plain sight so they can be watched but we push them away.

Behind closed doors is where people die from drugs and where teen pregnancy happens, it doesn’t happen hanging out on the street corner.

These need to be hacked to play high pitched techno that only teenagers can hear.

I'd settle for blasting something loud directly at people who came up with, approved, and implemented the idea. "but one that only teenagers and young adults can hear" is a lie of averages. High pitched sounds in my mid-30s are more annoying than any teenagers.

They don’t have the range to be that detailed. But there was a fad where teens would use the tone on their phones.

You joke but many of these sonic weapons in the UK have been replaced by speakers playing musak versions of opera. Bad classical music deters young people more effectively.

First they came for the mosquito... but I was not a mosquito... then they came for the rats... but then i was not a rat... then they came for the teens... but i was too old to be a teen...

We need more places in our society for people to exist free of charge.

Reminds me of how Zoom Rooms play ultrasound to automagically pair your computer to the room [1].

For a while I thought I was going crazy hearing this incredibly high-pitched, faint chirping in meeting rooms when no one else could (I have weirdly good high-frequency hearing). There's probably a solid limit to how far into inaudible ultrasound Zoom can push this sound, though, considering that computer microphones are designed to pick up things that people can hear.

[1] https://support.zoom.us/hc/en-us/articles/214629303-Direct-S...

Guessing not long before someone fills that thing with expanding/hardening spray foam.

I don't understand how it's even legal. Certainly the sound carries beyond the boundary of the park.

I fully intend to break these devices if I ever hear them. I'm over the age of 30, and can hear them quite clearly; it violates my right to be in public spaces. Even if the device is installed in privately owned property, it's not like the sound waves magically stop at the end of that property. Regardless of the law, the use of these devices within hearing of public space is against the public good, and they should be destroyed if heard.

One of the joys of aging to me is being immune to these noises while still enjoying music to the fullest. When I was young it was often agony going into stores that had alarm systems employing these high-pitched hums. Neither of my girlfriend nor her family, with whom we spent a great deal of time, could hear them. They were patient but bemused at my reaction.

Were these some sort of deterrent? Or just an inadvertent hum from electronics that were designed and QA'd by people who couldn't hear it?

I believe it was a side effect of the alarm’s circuitry. No one ever gave me a sensible explanation.

When I was a kid the local 7-Eleven installed outside lights that made your skin have a slight greenish hue and which made acne stand out. Great way to get rid of loitering teens without any harm.

I wonder if these things have any causal effects for developing tinnitus.

I'm assuming a hearing loss lawsuit (in the US) could fix this.

This confused me for a second. "Why is my ISP playing high-pitched noises? Surely it is not their core competency."

I am way over their age but can hear it. WTF.

I'm 53 and can still hear and feel 17KHz. I truly dislike these devices.

Wouldn't earplugs negate this?

In my experience earplugs/headphones are real effective for low frequencies but somewhat less for high pitched sounds.

Thinking about it, it's probably related to the material used for the plugs, I think I've only used foam type earplugs...

Implied at the start of the article but not mentioned until halfway down: they are only operational from 10 p.m. to 6 a.m.

What hours are these parks open to the public?

The playground mentioned in the article doesn't seem to have any hours posted online. But if the sound propagates outside the boundary of the park,

> [...] said she can hear the Mosquito installed a few blocks from her Fishtown home

I'd imagine it'd be disturbing even when the park is closed to the public.

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