Combating Harassing Use of Mosquito Noise Device?

amicold asks: "For a while now my neighborhood has had to deal with an elderly neighbor who has displayed a slightly paranoid attitude towards myself and the fellow younger-adults of the neighborhood, believing us to be attempting to harass him in our day-to-day activities. Recently, he installed a Mosquito ultrasonic noise device as an apparent attempt to 'get back at us' for our harassment. As the Mosquito emits a sound that's well out of his hearing range, he can't hear it, while most of the rest of the neighborhood is under 40 and can; at which point it's causing everyone a great deal of discomfort. Unfortunately, because the police also can't hear it, we can't get the authorities to do anything about it, leaving us empty-handed in our attempts at getting some peace and quiet back. What can we do to either help the police realize how disturbing this device is, or counteract it so that it's no longer disturbing us? And is this the first of what may be a growing trend of civilians using high-tech discomfort weapons as a method of neighborhood warfare?"

Re:Quit bitching

[ivan256]

Yeah, that will work great in a two dimensional world. Here in three dimensions it will suck a lot in all the places where amplitude is doubled instead.

Re:Quit bitching

[ToasterofDOOM]

That will work, but only at certain angles. Really, you don't need to 'Phase shift' it, that happens naturally. All he needs to do is play the sound an integer + 1/2 number of wavelengths away from the original source and at the same volume, and he should be as close to inline with both sources as possible. Really, you were right in concept though. It's basically a moire effect for waves http://en.wikipedia.org/wiki/Active_noise_control [wikipedia.org] http://en.wikipedia.org/wiki/Phase_cancellation [wikipedia.org]

£495 ...?

[euxneks]

This guy spent £495 to annoy the shit out of you? Either you deserved this, or the guy is a complete prick, in the latter case, fight fire with fire. Get some _very_ large subwoofers, a good amp, and play a song like Hootchie Mama [stlyrics.com] by 2 live crew, or if that's not your style, maybe something like "Superpredators" by Massive Attack.
    Or, even if you don't like that, just find something with real spleen shattering bass and just blast it.

Also, for those interested, I found a link to the mosquito sound here [bbc.co.uk] from an article at the Beeb here [bbc.co.uk], also, another interesting turn-around:
http://www.boingboing.net/2006/05/24/kids_turn_tee n_repel.html [boingboing.net]
Quite fascinating...

Re:Hmmmm

[Mr. Slippery]

Not a generic link.... say a wiki. I mean, who really believes that some guy cannot get a cop under 40.

I believe this device is only made by one manufacturer (patented, probably). And according to the web site of the anti-social child-torturing bastards ("Won't somebody please think of the children, and ban this horrible thing?!?!") who make this device, the high frequencies it uses are generally inaudible to people over 20.

Re:Well, you could start by...

[mcrbids]

Yeah, but once you are off the damned lawn, then what?

I'd suggest that taking a look at a book that takes the subject seriously [amazon.com].

When somebody "gets one over" on you, there are a bazillion ways to fight back. This is a funny, insightful, and comprehensive explanation of just how many options you really have.

It's amazing what you can do with a $0.99 bottle of super-glue! (Hint - a drop or two in each keyhole of his car door locks can be very entertaining)

Re:Try this

[NormalVisual]

I guess other people really can't hear when the TV is left on.

I can. It's the flyback transformer in your set making that noise - a very loud 15.75 KHz tone. I'm almost 40 years old and haven't taken real good care of my hearing, and it still bugs the hell out of me. One solution to the noise problem is to get a non-CRT television set (plasma, LCD, DLP, etc.).

Re:still out of luck, time for plan B or C.

[Rudolf]

He might really just be out to get the bugs? Offer to buy him a better model bug zapper.

If you follow the link in the story, you'd see that the neighbor in question did not install an insect control device (bug zapper) but rather something specifically designed to annoy young people and drive them away. (Mosquito is the brand name). From the link:

The Mosquito ultrasonic teenage deterrent ... With an effective range of between fifteen and twenty meters Compound Security Devices field trials have shown that teenagers are acutely aware of the Mosquito and usually move away from the area within just a couple of minutes.....Mosquito ultrasonic deterrent can solve your problem.

Did he tell you he was out to get you...?

Based on the device the guy installed, I think it goes without saying.

Re:Quit bitching

[mlyle]

You sir, are an idiot.

The wavelength of, say, 14KHz sound is very, very small [google.com] -- about 2.5cm.

Therefore the "shadow" cast by a cancelling device is also very, very small unless the out-of-phase canceller is right next to the noise source. The phase of the canceller will reverse (making things louder rather than quieter) every 1.2cm of distance difference between (the listener and the sound source) and (the listener and the canceller).

So, if you're say 10 meters from the canceller, and 20 meters from the guy's noisemaker, and the devices are in line (the best case) with your present position... you just need to go about .7 meters left or right for things to be at double intensity.

Not really a practical solution.

A sound level meter won't help

[Animats]

This thing won't produce a reading on a standard sound level meter. There's a standard bandwidth weighting ("A-law") for sound level meters, based on data about hearing damage, and it cuts off at only 8KHz. That's the definition used in most noise ordnances.

Re:Try this

[kc8apf]

Sadly, even the DLP TV I have creates a whine. The power supply for the lamp is more than likely a flyback.

Re:Well, you could start by...

[Anonymous Coward]

You could fight back in two ways

Use 2 directional low frequency drivers pointed at his house that would cause him to have a bowel movement.

"Strong infrasonic or ultrasonic sound waves passing through the head, neck, or chest can cause gasping for breath, head pains, or a choking effect. The firing point of the weapon could be from inside of the house next door or the inside of the house across the street. Since the weapon is hidden inside of a house and no damage is done to either house, it is virtually impossible to visually detect it. The wave after striking its target and passing through the targeted house will dissipate in the atmosphere over a distance. This is truly a vanishing bullet. "

Use 2 different directional high frequency (ultra sound) drivers pointed at his house from two different places but focused at his mosquito device. One at 38kHz the other at 40kHz. Where the two wave fronts meet there will be a loud interference tone of 2kHz.

This is the system used in the Yahama Sound Stage.

Re:Try this

[Henk Poley]

That's called 'coil noise'. There are a couple of coils (circular wound wires) on the motherboard. Normaly they shouldn't have any room to move a bit, but if they have they will vibrate in their magnetic field. You can use a tube to find the offending coil. Put the tube to your ear and move with the other end over the motherboard until you find the spot that emits the noise. Applying hotglue seems to be the most effective way to cancel the noise.

Re:Ask Slashdot?

[arivanov]

If it is in the UK you can use the standard laws against nuisance noise for which you do not need a lawyer. Dig the relevant address of your council website, write a well written letter and off you go. Same as with security lights shining with your windows. No need for using your lawyers. This is something you pay for using your council tax.

Most other legislations around EU (and many other countries outside it) are not any different. All you need to do is find the relevant local council address and send a complaint. They will send an engineer with measuring equipment at your site ASAP. The mere appearance of the van with the measurement equipment may be enough for the idiot Meldrew clone to take his Mosquito and shovel it where sun does not shine.

Re:Hmmmm

[Anonymous Coward]

No, this is a real story. I actually wrote it based off of a forum post [anandtech.com] by someone else as a quasi-humorous way to see how the Slashdot readership would handle it.

Re:Why don't you try... getting along?

[Frangible]

"I believe that Gandhi's views were the most enlightened of all the political men in our time. We should strive to do things in his spirit: not to use violence in fighting for our cause, but by non-participation in anything you believe is evil." "Generations to come will scarcely believe that such a one as this walked the earth in flesh and blood." -Albert Einstein

Re:Well, you could start by...

[NeMon'ess]

What would you call it if the neighbor was deaf and so could play loud music audible to everyone else, 24/7? People wouldn't be able to open a window without hearing it. Maybe even with the windows shut it's still audible inside the house. It's not destruction of property, but it's at least as vile.

Re:Noise Cancelling

[Anonymous Coward]

Not really. For this to work, you would have to hit exactly the same frequency and opposite amplitude. Which is a bit of a problem, if your 'cancelling wave' emitter sits in a different place than the original source as the amplitude decreases with distance from the source. Now try to imagine two sources and where their amplitudes would match (possibly on a plane somewhere between them, definitely not in the whole space).

Re:Quit bitching

[Anonymous Coward]

I'd like to believe that you're trying to be funny, but on Slashdot that would be wild optimism. The original poster did the calculation using the speed of sound. Your calculation uses the speed of light. You would appear to be the idiot.

Re:Ask Slashdot?

[antoinjapan]

Except in the UK the council puts them up.
http://www.compoundsecurity.co.uk/deterrent_news_8 5.html [compoundsecurity.co.uk]

Re:Ask Slashdot? - Civil Lawsuit

[Anonymous Coward]

This is one of those time a civil lawsuit is probably in order. The illegal device [compoundsecurity.co.uk] the old person bought is specifically designed to annoy young people by way of emitting ultra-sonic (to old people) sounds that, well, annoy young people. Take lots of pictures of the device on the old person's property, turned on and set to do its deed. Get young witnesses to sign affidavits attesting to the audible and annoying nature of the sound. Then all you have to do is also enter all of the product literature for this particular device into the court record. Since this device is specifically designed for one purpose -- to annoy young people -- and its sound emissions do not stay on the property of the old owner, the old owner is certainly responsible for what it is doing to the young people's enjoyment of their own private property and any adjoining public property.

Of course, first sending a very gracious but firm certified letter asking for the removal of the nuisance can only help your side look good and reasonable.

Re:Ask Slashdot?

[Maximalist]

Well, initiating a lawsuit shouldn't be beyond the ability or budget of anybody here. Depends on your state, but some places you can file a "Writ of Summons" that lets the other party know you've got beef with them, and open the door to discovery for you, without having to draft a proper legal complaint. The pre-complaint discovery is to help you draft the complaint... If the form for the Writ wants the gist of your action, the magic word here is "nuisance". Serve the grumpy old geezer with a Writ, and then serve him with interrogatories asking all kinds of information about the device, where he purchased it, when he installed it, why he installed it, what its specs are, etc... . If he ignores them, then pay a lawyer to argue for sanctions for contempt of court for his disobedience of the order to answer them that comes with the interrogatories. Where I am, you're looking at a total bill of maybe $500 at that point, and most of that is paying the lawyer to put the screws to him. If the lawyer is good, you might get attorney's fees assessed against the grumpy old guy too, so you costs just went way down again.

Re:Well, you could start by...

[speederaser]

"...maybe because he can't HEAR it he doesn't know there is a problem?"

According to the products page [compoundsecurity.co.uk], the purpose of the Mosquito is to drive teenagers away from an area by producing high frequency sound only they can hear. Older people cannot hear it. The device has no other purpose, and is certainly not a mosquito repellent device as some posters have assumed.

Scotch tape

[Anonymous Coward]

It's amazing what a piece of scotch tape placed strategically over the sound emitting port of most modern electronics will do. In this case, it would also have the benefit of avoiding vandalism.

Of course, you would have to trespass to place it there...

Re:I call bullshit

[TBone]

Call bullshit if you like, but Cingular sells 7 of them, in increasing frequencies, on their CingularExtras site.

We run that site at work, so of course, we've tested them all. Most of us back in Operations can hear the first 4, with the exception of 3 guys - 2 in their late 30's, and one in his mid-20's. Those of us that can hear it (8 of us) range from early 20's to late 30's. About half of us can hear the 5th one. A couple of us can at least tell that the 6th one is doing something (including me at 32), and only the mid-20 year old guys can hear the 7th one.

WTF?

[Anonymous Coward]

Did you ever consider that maybe because he can't HEAR it he doesn't know there is a problem? Can you talk to him about it calmly and respectfully, or have you already become such bitter rivals that you would/could never do that..

While I agree with the vein of your argument, the above comment just shows that you don't know anything about this thread. The device he installed does only one thing: create a high-pitch annoying noise that generally can't be heard by older people who have lost that range. He certainly knows there's a problem, because he purchased a device developed to create this problem.

Re:Try this

[nsayer]

If you remember Heathkit, then you're more likely in the old coot's camp than in the kids'.

Re:Try this

[Anonymous Coward]

Since it is just a high frequency sound wave, then there aren't any compression artifacts--the frequency transform will output all zeros except at the one high frequency. The quantizer (the lossy step) will get something that is already nearly all zeros, and so has nothing to quantize. Then the entropy coder does it's job, which is lossless anyway.

This is just about the perfect sound to run through MP3 compression.

Re:Try this

[Anonymous Coward]

If you can't hear this, try playing it on another set of speakers. I'm not quite 27, and I've always had good high-range hearing, but I was surprised when I couldn't hear this tone when played through my soundsticks (those weird clear plastic things that were all the rage at Apple stores a few years back). I tried it on a pair of headphones and nearly had a heart attack.

auto-fightback

[samjam]

Get a mosquito sensor, to detect when it is turned on, use it to power a 12Khz sounder focussed at his windows.

When he turns of the mosquito noise, the noise he can hear will go off.

When he turns it on again, he will hear it.

He will think it has gone wrong; and you know he feels the same pain you do.

Sam

Re:right back at them

[JamesKelley]

I would just sneak over his fence and physically disable the componet that makes the noise. He won't know it is broken, and you can just act like it is still working. That way he will be happy and so will you.

Re:Well, you could start by...

[BalanceOfJudgement]

Assuming that your speakers can reproduce the frequency of course :)

At first I was thinking "Blast.. I AM going deaf..."

Then I realized my speakers only go up to 16KHz. :) I need to find some other speakers to try this on...