Mosquito tones

[ljbirns]

Did anyone see hear about this. High school kids are using high pitched ring tones in school ( where they are not supposed to have cell phones ) because the high pitch cannot be heard by older people.

here is the tone   >.http://graphics.nyti...0060610_RINGTONE.mp3

Works too.   I can't hear it but some of the younger folks at work CAN.

It supposedly started in England by shopkeepers to drive away young loiterers and no annoy their older customers.
From The New York Times

Lew

[nudone]

i heard about this on BBC Radio 4 the other day i have to say i could hear the tone when they played it.

i can also hear the tone that is in the link that ljbirns has provided but it does sound of a slightly higher pitch than what i heard from my car speakers that i was using to listen to the radio broadcast.

i wonder how the tone is effected depending on the quality of the speaker and the volume it is set at.

oh, i'm 37 so i shouldn't be able to hear it. there were  plenty of people calling in to the radio show saying they could hear it also even though they were meant to be too old.

i am very surprised that the tone is meant to be outside the hearing range of anyone over 20 years old - maybe if you have the volume right down and use a poor set of speakers ???????????

i guess for all us old timers that can still hear it we can feel like we've got one up on those darn whipper snappers.

[KenR]

Hey Nudone,

As I'm sure we are ALL aware, it is normal for people (in other words average - some very little, some a lot) to lose the ability to hear very high frequencies as they age. However, I think the idea that there would be a marked dropoff from the time one is 20 to the time one is 40 is simply absurd.

KPR

[jgpaiva]

I tested this a bit, and got to the conclusion it's too uncertain to actually be used.
When I can listen to it (i'm 21), my mother also can (she's 45). Another bad effect about it is that if i had a ringtone like this, i probably would go mad and knock the cell phone against a wall, as even my slow, low, not irritating ringtone drives me mad!

[ljbirns]

I'm 62. I could not hear it. The oldest in my office that could hear it ws  46.

Lew

[mouser]

i could hear it.. and i did not like it 
sounded like my ear was broken.

[Carol Haynes]

I can hear it (and I am 48) but I wouldn't like to rely on hearing it for my telephone !!

The weirdest thing is the my house mains electric fuse tripped as I clicked play !!!

Good test for my UPS

[noth(a)nk.you]

The paper here featured a similar article (syndicated from Paul Vitello, NYTimes).  According to him, the frequency of annoyance is 17 kHz. 

I used Audacity to create the tone on my laptop, but the speakers couldn't produce it.  The home stereo speakers, however, played a burned .wav wonderfully.  At least, so I am told.

I couldn't hear it myself (age 20), but my brother (age 19) reported immediate annoyance.  Turning the volume up to about 20%, I heard a tone pretty well, but I expect that the speakers just couldn't handle the high frequency at that amplitude and "dumbed it down."

Could perhaps a similar "dumbing" effect be in place when

• compressing to .mp3
• broadcasting over radio
• both

Perhaps this could rationalize my hearing loss!

[Edvard]

Yes this could be the mp3/cd encoding. There are a lot of complicating things going on in the upper end of digital music which is where DVD audio wins. That is 24 bit and 96 kHz sample rate which is high enough to translate the upper range of audible material accurately. (human hearing in the extreme tops out at around 20 kHz) standard cd audio is 16 bit 44.1 kHz, so in the upper range, you get artifacts especially with mp3's you start hearing artifacts.
That's also why all the serious audio guys I know don't use Sound Blasters. They are tuned for mp3 playback. Waaaay lowpassed. My guess is the Mosquito ringtone is a pure signal (square wave at 17 kHz) so all the more annoying and no audio processing in the way...

[Carol Haynes]

I have an Audigy and I can hear it ...

[nudone]

i've an audigy also and i can hear it (as i mentioned above). i thought all pc sound cards would go up to about 20 kHz - i've not checked the numbers but 20 or 22 doesn't seem too unreasonable. maybe i'm living in a fantasty land.

[jdd]

it used to be that you were only as old as you feel.   Now, your're only as old as what you can hear.

[Carol Haynes]

I think it should be 'you are as old as you see' ... I seem to spend 50% of my time taking my glasses off and putting them on again!