Courtesy of shybThe Mosquito was invented by a store owner in England to repel loitering teens who made his customers uncomfortable. He played high pitch frequencies through speakers outside his store, and since high pitches are really annoying to kids and teens but can’t be heard by adults as well (or at all), the teens would leave but the adult customers could come in.
The highest frequency that may be heard by any human is 20,000 Hz. As you get older, your ability to hear high frequencies decreases.
Make your own Tones
- Computer with sound software, like Audacity
- CD player
- 1. You can create tones on a computer, using a free sound generating program like Audacity and test yourself and your friends.
- 2. In Audacity, make a new track, and choose Generate Tone... from the menu. Type in the frequency of the tone you want.
- 3. Make the tone the length of time you want (like two seconds), by highlighting and deleting the rest of the track. Add additional tracks and tones if you like.
- 4. You can export your tones as an mp3 or wav file and burn them on a CD, or play the sounds right from the computer.
- 5. Test yourself and your friends to find the highest tone you can hear. Keep track of people’s ages and gender to see if you notice trends about who can hear high frequencies and who can’t.
Download a PDF to print below