Introduction A high pitched frequency has been now called “Mosquito” or “Teenager Repellant.” It started when some old British shopkeepers didn’t want teenagers loitering around their shop. When the shop keepers put the “Mosquito” on, the teenagers hated it, but since the shop keepers were older, they didn’t hear it. The teenagers left because the sound. Now I’m testing who can hear it and who can’t.
What is frequency? All sounds are vibrations. Frequency is how fast it vibrates. Hertz are the unit of frequency. If something vibrates 500 times per second it would be 500 hertz. A human can hear 20 hertz to 20,000. a cat can hear 55 hertz to 79,000 hertz, and dogs can hear from 67 hertz to 44,000 hertz. 1 vibration per second = 1 hertz
Prediction I think some adults can’t hear it because their ears are older and are not as sensitive to that high of a sound. Also, I think people with hearing problems could not hear the “Mosquito.”
Supplies A set of headphones A computer with the sound “Mosquito” 5 volunteers Pencil Paper
Procedure 1.Download the “Mosquito” on my computer. 2.Plug in the ear phones 3.test my volunteers if they can hear it or not. 4.Have them write down if they heard it or not.
Results Mom- could barely hear it. Elise- could hear it clearly. Me- could hear it clearly. Will- could hear it clearly. Dad- couldn’t hear it.
Conclusion I think that why my Mom could barely hear it and my dad couldn’t is because when you get older, you can’t hear higher frequency. The reason why is because when you hear something, the sound waves press against the eardrum. The vibrating eardrum causes three little bones in there- the hammer, the anvil, and the stirrup to vibrate. The stirrup presses against a spiraled structure like a snail shell called the cochlea, were the hearing is. The cochlea is filled with a liquid and is rimmed with tiny hairs called cillia. When you hear something loud, it destroys the cillia and they can’t grow back. This is why some people can’t hear it.