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Repel Bugs With Your Cell Phone
telstar writes "Starting Monday, SK Telecom Co. in South Korea will begin offering a ringtone designed to repel mosquitoes for the one-time price of $2.50. The ringtone, inaudible to humans, has a range of three feet, and functions just like any other ring-tone from your cell." Now if only there was a ringtone to repel bugs in code! Sorry, I'm full of bad jokes today.
What good is this if it would run your battery down quickly? Better keep an eye on the meter so you have another power to call someone and tell them to bring you a can of 'Off'
Another case of mis-applied technology.
"The ringtone, inaudible to humans,....."
Ok, I give, how am I going to know when I'm getting a call then? Move to mosquito infested parts of the land, and wait for them to suddenly scatter?
Other than that, it's nice to see that now mosquitos will fall victim to people who just have to mess with their ringtones all the time.
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Talk sense to a fool and he calls you foolish. - Euripides
Does anything other than N,N-diethyl-3-methylbenzamide(DEET) really repel mosquitos?
It seems that every time they conduct these tests (just in time for mosquito season) the only products that do anything are the ones containing DEET, and the products using citronella, peppermint oil, baby oil, etc. are useless.
Whenever the offence inspires less horror than the punishment, the rigour of penal law is obliged to give way...
What you say (about 22 to 24 kHz) is true for audio formats that store sampled sound, but how many ringtones are really sampled sound? Desktop computers these days all use sampled sounds, but lots of simpler devices (Palm OS for example) use a much simpler method that will be familiar to those who grew up with 8-bit computers (Apple ][, Commodore 64, TI99-4/A, Atari 2600, etc.). What you get is an oscillator and a software interface that allows you to turn on and off the oscillator and set its frequency. Sometimes you get something a little more advanced, like the ability to do simple FM synthesis or generate white noise. I strongly suspect most cell phones use this sort of approach. I've never noticed one producing a sampled sound; it's always that tweedly, one-voice bastardization of Beethoven's 5th or something.
Having said that, I wouldn't be surprised if (read: "I'm going to wildly speculate that") there is a 16-bit register somewhere that lets you set the frequency in Hz. Which might give you an upper limit of 65535 Hz.
Probably the amp can reproduce 65535 Hz, but whether the speaker can is another question. If the cell phone has a separate piezo element for ringing, there's a sorta decent chance it can hit that tone. If, on the other hand, it uses the same speaker as it does for conversations, it's probably not going to get anywhere near there. Cell phones have no reason to be engineered to make tones that high, but it's not an especially hard thing to do, so it's possible that it can happen.
My point with all this? I don't think you can necessary discount the possibility of making a reasonably loud, say, 40 kHz tone with a cell phone. Whether this particular phone can or can't is another question, and whether it would repel mosquitos if it did is yet another question.
What format are ringtones stored in that they can represent tones beyond the range of human hearing?
Usually MIDI, or a proprietary format. I'm having lots of fun downloading and playing MIDI files on my SonyEricsson T310 phone. It supports up to 32 channels, and doesn't sound all that crap, actually. I wonder how long it will take for musicians to hijack mobiles and use them as fully fledged MIDI synthesizers. For that "sounds of the naughties" feeling!
Anyone know the MIDI chip in the SE T310? The trumpets and bells sound very clear (the other instruments are sometimes a bit muddy). Sounds better than the windows XP MIDI mapper anyway
SCO employee? Check out the bounty
"Inaudible to humans" means one of three things...one, too low to be heard (in which case mosquitoes won't care, or two and three, infrasound and ultrasound, respectively. The problem with that is that a cell phone cannot generate sounds in those frequencies with any reliability...it's not designed to. Infrasound requires a huge driver, and if you've ever looked at those devices that supposedly drive away aggressive dogs with ultrasound you know what an ultrasound transducer looks like, and it's nothing like the piezoelectric speaker a cell phone contains for ringtones. This is just an example of what happens in countries with more relaxed consumer protection statutes.
For your security, this post has been encrypted with ROT-13, twice.
http://www-rci.rutgers.edu/~insects/proprom.htm
q uito.org/mosquito.html
"Products and Promotions That Have Limited Value for Mosquito Control: Electronic Repellers"
"Hand-held electronic devices that rely on high-frequency sound to repel mosquitoes have become surprisingly popular in recent years. Prices range from $9.95 to $29.95 for units advertised in magazines. Heavy-duty repellers that claim to keep away spiders, hornets, and rats, in addition to mosquitoes may sell for more than $100.00. The manufacturer's rationale for using sound as a repelling factor varies from one device to the next. Some claim to mimic the wing beat frequency of a male mosquito. This, supposedly, repels females who have already mated and do not wish to be mated a second time. Others claim to mimic the sound of a hungry dragonfly, causing mosquitoes to flee the area to avoid becoming the predator's next meal. Most of the electronic repellers on the market hum on a single frequency. Top of the line devices allow for adjustment by the user to achieve the most effective frequency for the mosquito causing the problem. Scientific studies have repeatedly shown that electronic mosquito repellers do not prevent host seeking mosquitoes from biting. In most cases, the claims made by distributors border on fraud. Mated female mosquitoes do not flee from amorous males, and mosquitoes do not vacate an area hunted by dragonflies. Electronic mosquito repellers do little in the way of reducing mosquito annoyance."
Plus, more mosquito info (like you care):
http://www.njmosquito.org
http://www.mos
Losers choose to abuse the use of "loose".
I'm not a medical expert, but IIRC human ears have the ability to hear selected frequences well above the normal range. You might be able to hear everything from 20hz-14,600hz, and a few selected frequences up to 30,000hz, but others inbetween are inaudiable. The ones you can hear depend on your particular ear.
I think I understand how to explain it better, but it is late. Besides, I'd prefer those who care to do their own research to verify it, while the rest think "That's interesting I won't if it is true" than to take me as some expert.
These devices emit the noise of an "angry male mosquito", and because only pregnant females bite, they're supposed to get scared away by the sound of an angry male. The thing is, according to the packaging on my device, there are over 1400 species of mosquito in the world, and this only works on about 500 of them. It doesn't scare all of them away - some of them it just makes not interested in biting. And of course, there are those 900 species that it has no effect on.
I've used my mosquito guard thingie all over the place - from the mountains in WA state (I live in Seattle and camp fairly often) to jungles in central america (where I've been on several occasions). It seems to work on most mosquitos I've run across, both in the flying-away sense (luckily, the horribly-toxic ones that live around my house), and in the not-biting sense (about 90% of the ones in Costa Rica). Others (like some I ran across while camping last weekend) seem completely unaffected.
It's a gamble. But if I figure it prevents me the annoyance of a few mosquito bites, it's worth carrying around.
Do you really need reason for beer? Wingman Brewers
Mosquitos find their targets from the trail of carbon dioxide left behind by exhaling. So I have heavy doubts about this Korean invention working at all. What does work so far are those traps with their own CO2 generators. (But even then it is not perfect.)
Those high frequency sound generators may repel mice and rats, but only for a short period of time. What happens is that their offspring will come back to re-infest the area. The difference between the off-spring and the parents is that the kiddie rodents will be born deaf. Rodents like roaches are highly adaptive. (Got that little tidbit of information from someone who used to work in the exterminator business.)