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Driving Away Teens With High Frequency Noise
ars writes "The New York Times is reporting on a device called the Mosquito invented by Howard Stapleton designed to drive teens away by emitting a high frequency noise at 75db. Apparently most older people can not hear the sounds, but teens can not stand it. Reports are that it works quite well, but some older people can hear it too. He found the prefect irritating sound by experimenting on his children."
I actually have tried high-frequncy sound "bombs" for insect and rodent control before. Ramsey Electronics sells a kit that does similarly (and it's better-buiult than my old hacks).
Various waveforms at frequencies from 19 kHz to 26 kHz were tried, along with changing waveforms and amplitudes, plus some minor modulation. I used both conventional drivers as well as piezo units. Only limited results were had.
One thing that DID work (well, sort of) was a flyback transformer from a defunct Sony TV set. That annoyed women, but not men. Weird.
Maybe I was doing something wrong, but, I doubt it. I just think the whole 'dog whistle' idea is overblown as to utility, and it's not like I wasn't trying.
This is EXACTLY what I pulled in my undergraduate 'Modern Electronics' class. When we used small speakers I could adjust the frequency to a positively epilepsy inducing sound (especially if you ran the speakers on square wave functions with slight frequency scanning) that caused most of my classmates considerable discomfort but my professor (a fan of loud and live rock shows) could hear nothing. The best part is that he was proud that he was "immune" even though it indicates the beginnings of hearing loss.
75 db isn't going to make anyone deaf. Personally having owned a 140 db subwoofer system (metered) in my vehicle, I can attest that 75 db is not going to do any particular damage to my ears past what I've already done.
What are you talking about? This is just a device to stop teenagers from loitering. No one said anything about parents using this to get rid of their own kids.
Oh, Edmund, can it be true? that I hold here, in my mortal hand, a nugget of purest green?
I think this is a terrible idea for any number of reasons, one being that supposedly "inaudible" noises effect people subconsciously. Even if the people involved don't report hearing anything.
h tm
Relevant link with EEG results-
http://www.cco.caltech.edu/~boyk/spectra/spectra.
A little of both. The horizontal scanning frequency is 15,750 Hz (I think) and some but not all teens could hear it. I could, and going into a TV store would drive me nuts. Time and lots of rock and roll has cured that problem, and I no longer hear the TV sound.
So yes sound wave could be tuned so that some, but not all could hear it. You might annoy some adults, and be ignored by other kids.
Problem is, kids AREN'T going around shooting and killing each other, at least not in the US.
The FBI reports that crime overall has gone down steadily since 1994. The most recent stats show that 2004 had the lowest level of violence in over 3 decades.
I wish I could find the specific graphs on this, but here's the raw data for each year... and if you take the time to look at it, it also shows that juvenile crime specifically is at it's lowest level in over a decade.
Old people can get away with just about anything.
RTFL. It doesn't say that listening to sounds at 75 dB can cause hearing loss, it describes a hearing loss of PTA 75 dB as basically deaf. If sounds at 75 dB caused hearing loss, we would all go deaf from the sound of our own crying as babies long before we learned to speak.
English is easier said than done.
The main reason for this is chavs, don't understand it, look it up. These are roving gangs of teens in England that like to fuck with people for no reason at all. Oh, and look up happy slapping while you're at it (honestly).
Isn't this just going to make the kids as deaf as the adults?
;-)
I seriously doubt it. This just takes advantage of high frequency sounds that you can hear when you're younger, but don't necessarily find yourself completely unable to stand. A perfect example of this sound was the high pitched whine of the old televisions.
Can I get a show of hands for every person here who couldn't stand the bloody noise from the things? Sure, you got used to the sound (since you wanted to watch your favorite show), but it was never the most pleasent. Anyone here ever ask their parents if they could hear the sound? How many of you had your parents answer, "What sound?" (/Me raises hand)
With luck, your hearing will be acute enough at an older age to still hear the whine of those old televisions. However, the majority of people lose the ability to hear the extreme ranges through a natural amount of hearing degradation with age. At least, I've never heard a link between those old televisions and loss of hearing. So I wouldn't be too worried about this guy's invention.
Unless, that is, you happen to be a teenager or an old fogie with exceptional hearing.
Javascript + Nintendo DSi = DSiCade
Some good classical music with maybe a little John Tesh thrown in for good measure. Just don't make me haul out the "big guns" and start playing some Celine Dion!
They that can give up essential liberty to obtain a little temporary safety deserve neither safety nor liberty.
Ben
A McDonald's near me runs off the teenagers with a ~60db loop of the 1812 Overture. I love watchin' em try to talk on the cell outside with an index finger jammed in their other ear up to the second knuckle.
Near Halloween they switch it to Bach's Toccatta and Fuge in D Minor. Really cool for 90 seconds and then you know what Manuel Noriega must have felt like and need to flee.
We really need your help
http://www.gofundme.com/help-sherry
Here's a clue: someone with 75dB hearing loss at a given frequency is incapable of hearing a 75dB signal (that means they probably won't year you at all, even if you get up in their face and scream at the top of your lungs). To them, a loud car horn at 115dB would sound like background noise sounds to you (i.e. very quiet), and a jet taking off at 140dB (which would cause you PAIN) would be the equivalent of you hearing normal conversation. In short, "deaf as a doornail."
See this SPL table:
In conclusion, hearing loss != SPL. They're both expressed in dB, but they're not the same thing. Hearing loss is subtracted from SPL.
People *are* animals, and we *can* herd them around as such. People put a lot of research into the layout of stores to get people to impulse-buy things or to go in a particular direction. Research dictates where you put doors and railings to keep people from stampeding and blocking an emergency exit in the event of an actual emergency. Where there is a lack of "people control", people will trample over each other to get inside a Wal-Mart the day after Thanksgiving, or surge forward at a soccer (football, for the non-Yanks) match, crushing people into the front railing. They'll go rioting through your favorite large college town, burning and flipping cars, breaking into stores, looting, and throwing rocks at cops.
Yes, parents need to step up and control their children. But just because there's a "should" out there that would prevent most teens from displaying antisocial behavior doesn't mean that shop owners should sit back and let the kids whose "shoulds" are unfulfilled go rampaging through their shops. This is a great idea meant to solve huge problems of vandalism, theft, and assault because the parents who should don't. By your logic, people should just stand around and get victimized, mumbling, "Where are these kids' parents?" under their breath.
I've posted elsewhere that I think the GP's comments are a bit overdone, but for the record: lip reading only gives you 30-50 percent of the content under ideal conditions (lighting, where the person is facing, whether they lip speak well, etc), and even then it's very tiring. Definitely a useful skill, but it's not as great as people think.
Get yourself a frigging dictionary (or go dict.leo.org ) and look up "Geiz". It has lots of translations, but none of them is "greed". Closest one is probably "stinginess".
"Greed" refers to "want to have a lot of (usually money)", while "Geiz" implies "not wanting to spend a lot of (usually money)".
You can actually calculate what the audible frequency is of a TV.
For NTSC in North America:
For PAL in the UK:
And yes, the sound drives me crazy, too. I'm 30 and an audio engineer. And I'm the only one in my household who can hear the damn TVs whining. :-)
Jory
The high pitched sound is impossible to track and very annoying :)
d /boxes/pandora.html
Plans to build one:
http://www.linuxsavvy.com/staff/jgotts/undergroun
I've witnessed a gang of kids being herded in to a Police van after being arrested for dropping concrete blocks on to a busy motorway. You've never seen a more angry bunch; they were livid that the Police had put an end to their little game. Their complaints alternated between "You can't do this!" and, comically, "I've got rights!". Sadly, despite attempting to murder a number of motorists, they were probably released with a caution.
Thanks to these poor, oppressed little dears the centre of many UK towns are no-go areas after 10pm. Anything that allows law abiding, tax paying citizens to protect their business from these little shits is to be applauded.
Sand, cat litter, and rock salt are also excellent passive skater deterrents.
Personally, I want one of these devices that works on senior citizens. There's a gang of grannies who hang out near my store, harassing young people and keeping the town in a constant state of fear.
Oh that's easy. It's called Rap Music.