How Good Is Your Hearing?
Finally, an easy way that explains how dog whistles actually work. Dog whistles usually put out a noise at around 22 khz (kilohertz), any higher than that and the noise become inaudible to the human ear. This method works because the shrill high-pitched noise heard by the dog is completely undetectable by any surrounding human, enabling the human to annoy/train the dog to their own heart’s content. Recently I heard about a certain ringtone that plays a high-pitched noise that are inaudible to older people, (making it perfect for in class,) so I decided to do some research.
Thanks to some quick googling I came across MosquitoRingtones.org. They have 13 individual audio files ready for download, and those 13 files are listed below. The amount of “khz” is the measurement of the pitch in kilohertz, and the age group that should be able to hear it is listed right next to it. Be warned however, that this is not an exact science. I am 19 years old myself and I believe I have good hearing, yet I wasn’t able to hear two of the tones (18 & 19 khz,) that my age group suggested I should be able to.
Before you test them out, here are some quick guidelines to make sure you’re not doing it wrong:
1) Make your room (or wherever you’re listening) as quiet as possible. That means turning off iTunes, closing the window, and shutting off sound as a whole. If you’re trying this in a public place, headphones might be enough, but near-perfect silence is preferred. Which brings me to my next point…
2) Speaker quality is very important. Not every speaker might be able to play the higher-pitched (and therefore harder to hear) sounds. To make sure it can play any, try the 8khz file. This should be audible to anyone under 60. Still, some speakers might be able to handle this noise and not others, so take note of that.
3) One last thing. If you have good speakers but can’t hear something, and you’re fairly confident its not due to your hearing, make sure the sound is playing. To do this, make sure your volume is on full (and not muted), and open these files with Windows Media Player or iTunes. Enable the “visualization” feature. If you see a visualization for other songs but not these, then there’s something wrong with the sound file. If you see the visualization for these files but still can’t hear anything, it’s either your speakers or your ears.
Here are the files, along with who should be able to hear them. Test them out on your friends and relatives: