Freesound Forums

Just because you can't hear it doesn't mean it's not there

There’s something I have been talking about for a while and have mentioned to many people in the last few months, often elliciting the reaction: “You’re making this up aren’t you?”

Last summer my 9 year old son Billy told me there was a weird high pitched sound in a shopping centre here in London.
I asked him to take me to where it was and I stood there and tried to hear it. I couldn’t hear anything.

He thought I was going deaf.

I thought I might be going deaf.

Or that maybe he had tinitus.

It turns out that it’s a sound that shops use to deter young people from their stores. It’s so high pitched that people over about 25 can’t hear it.

So I’m not going deaf. (Well actually I am but no more than anyone else over about 25.) Billy doesn’t have tinitus. He’s just a normal young person who can hear high pitched sounds.

And I wasn’t making it up. It’s called the Mosquito and it’s finally appeared in the national news in the UK:

news.bbc.co.uk/1/hi/uk

Here’s the website of the people who sell it:

www.compoundsecurity.co.uk

You can hear the sound (or not) on my list on freesound. (I've done a version where I've pulled the pitch down so if you're old like me you can get an idea of what we're inflicting on young people.)

I’m feeling confused by what seems like a barbaric act.

I’m glad it’s come to light. Sad that it’s being sold. And I’m a bit jealous of teenagers and people under the age of about 25.

If they can hear the Mosquito, what on earth else are they hearing that we can’t? In music, in speech, in nature...

Yours in a low pitched kind of way,

KJ

I'm 17 and here in Québec shopkeepers don't use it (yet) as a teen-repellent. Teenagers use it as a stealth ringtone instead. I agree this is very barbaric. The unconscious people that created this product don't even know what this sounds like. It's hear-splitting, and if all shop started playing this in front of them, it would be a very anti-social act, even more anti-social than the supposedly delinquant teens.

it's interesting to say the least... but to digress a bit.... i wonder what the precise frequency is that the ATF used in waco, texas? anybody know what i speak of? i know it is low frequency and that it supposedly caused fatigue and sickness. (i need to start a thread about "sonic levitation" :twisted:

thedialogueproject,

that is a very distressing post.
you should take it up with the media - because this is reducing the time your kid will hear these high frequencies.
basically, they are making your kid deaf - in the higher frequencies.

- bram

I agree - this is barbaric.

The story has only really just broken in the UK. And if it is indeed making kids lose their hearing in these frequencies, it's nothing short of abuse. Would love to hear from anyone with technical knowledge in this area.

Thanks for the posts. Let me know if anywhere else in the world is suffering from this extraordinary display of adult ignorance...

(By the way - kids are using it as a ringtone on their phones so adults can't hear it.... Seriously.)

KJ

This device is the complete antithesis of the freesound ethos and that of all freesounders - it is sound as weapon. An assault on the human condition and also a perfect example of corporate greed over-riding normal values. The device will solve an immediate local problem by moving people on but this does not make them disappear - they just take their problems elsewhere.

What about this for a solution - the under 25's themselves should make a vow never ever to use the shops or companies using these devices as long as they live and their families and friends should do the same. A bit of direct action - and a boycott will hit them where most of their feelings are - in their pockets.

Yup - the mosquito. This device has been in use since quite a while at different locations in my town. While I agree that sound as a weapon is awful I can't deny that it is functional to keep public places slightly more public. Let me try to explain this. You see, some areas such as metro stations or obscure squares have become the habitat for certain youngsters. This is nothing new and young people should have a place to hang out. But at the spots I'm talking about the groups grew bigger and bigger and their behaviour towards others became very aggressive. So the public space turns into their territory and becomes less public. You know there is something wrong if people don't want to use a metro station anymore.

So, that device was installed. And the groups dissolved. I'm not saying they seized to exist but at least they didn't move to another place together as a group. The devices are installed at places (e.g. entrances) that other people ususally don't stay for a long while so it doesn't bother people passing by. It is only bothersome to people who stay there for a long while. Also, the mosquito has fairly short range so it is rather local.

Altogether: yes I understand your feeling but at the same time I have to admit it is functional in some places.

By the way, some elderly complained they could hear also the noise. I couldn't.

PS: For those of you living in the Netherlands and curious to experience it: the mosquite is in use at the Rijnhaven and Maashaven metro stations in Rotterdam and at some other spots in Charlois (Rotterdam Zuid).

LG
PS: For those of you living in the Netherlands and curious to experience it: the mosquite is in use at the Rijnhaven and Maashaven metro stations in Rotterdam and at some other spots in Charlois (Rotterdam Zuid).

LG, would you record it sometime and upload, please? I'm curious...

@ dobroide: sure! But my recorder is broken down and still saving money for a new and better one so it may take a while. But I'll record it for sure.

i wonder what would be the best way for the individual to combat this type of thing?.... ear plugs? ....cut the wires? ...somehow aim another frequency at it and cancel it out? anybody?

play another signal with a frequency very close to it: by SLIGHTLY modulating the frequency of the second signal you can modulate the first and make it thus hearable for EVERYONE.

that's actually a very good experiment. can someone please go figure out what frequency this thing is at?

- bram

Bram
play another signal with a frequency very close to it: by SLIGHTLY modulating the frequency of the second signal you can modulate the first and make it thus hearable for EVERYONE.

that's actually a very good experiment. can someone please go figure out what frequency this thing is at?

- bram

according to thedialogueproject, 4 kHz and 16kHz. For spectral images see my comments here:
http://freesound.iua.upf.edu/samplesViewSingle.php?id=48257
and here:
http://freesound.iua.upf.edu/samplesViewSingle.php?id=48258

About fighting the thing... I'd wish to know if the shop warns visitors about the sound they are being exposed to. And it might be interesting to ask a lawyer about the legality of the technique. Taking actions againts the shop would be a nice way to fight this,..

D

bah they modulate the tone itself, that's perfect. if you play a 16khz sound right next to it - or even in the neighbourhood- it should sound pretty damned funkie. Give it a shot: mix that file by thedialogueproject with a straight 16khz tone and see what happens.

of course I could be wrong.

if that fails mix it with a 16khz + something tone (dobroide could you figure out the actual frequency of the higher pitched part?)

- bram

Bram
bah they modulate the tone itself, that's perfect. if you play a 16khz sound right next to it - or even in the neighbourhood- it should sound pretty damned funkie. Give it a shot: mix that file by thedialogueproject with a straight 16khz tone and see what happens.

of course I could be wrong.

if that fails mix it with a 16khz + something tone (dobroide could you figure out the actual frequency of the higher pitched part?)

- bram

http://img259.imageshack.us/img259/5411/mosquitotonefa2.th.jpg

I love the idea of hurting back the hurters... would be very happy to try out anything this weekend. But I don't have time to create the file. So let me know if you get anywhere!

KJ

i'd like to thank bram and everyone for getting all "guerilla mad scientist" on this one... that's exactly what i was getting at. :wink:

Public place are supposed to be healthy and wholesome for all age groups, or they aren't public places. That this is even being allowed is insane. It's targeting children's ears, which are still fragile and growing. So they're meant to stop people from hanging around or visiting? what about kids that are with their parents, and have to deal with the children's complaints of ear aches? Kids that are being made deaf to certain sounds? It just... *sigh* I can't believe this is serious. :x

This today from an articulate young man I know in Scotland:

Dear Karl James

I certainly agree with you. It is destroying our human rights. I am a near teenager at 12 years old and I am not a dumb yob with no self respect. They are not respecting our rights and it is aganst many acts in the universal decloration of human rights. It is realy anyoing noise and some of or older users say that it is anoying as well. I think that it is just like some modern wepons used in ww2. The people who install it are ignorant little tyrants and I bet soon someone will take this to court.
Thank you for your debate subject and I shall bring this up with my peers

Mark (Full name Name withheld by KJ)
Chairman and Room 13 Regular

Here is the actual weapon of mass destruction. It can't be heard while in preview mode (the lo-fi version that is played probably had this "unhearable" frequency chopped off) , you'll have to download it. If you or someone around you might hear it, TURN THE VOLUME DOWN. It hurts. Really.

http://freesound.iua.upf.edu/samplesViewSingle.php?id=48308