How Far is a Hertz? ```Name: MJhari Status: other Grade: 4-5 Location: NY Country: USA Date: N/A ``` Question: Hi my name MJhari Lewis. On December 8, 2010,Louis M. Huzella, DVM answered my question about a cat's eyesight and hearing. He mentioned a cat's hearing range is measured in hertz. I want to know how far is ten hertz? Replies: MJhari, I believe this is one of those cases where terms used by scientists can be slightly different than what you might expect. When DVM said hearing range, he/she meant the different pitches of sound a cat can hear, not the distance away. When we hear sound, we are really hearing vibrations of air (or water if your head is underwater :). A vibration means something moving back and forth, like for instance a vocal cord or a guitar string. If a guitar string vibrates slowly, it will sound deep, or "low". If it vibrates quickly, it will sound "high" or squeaky. The speed at which something vibrates is measured in Hertz. It means "the number of times something happens every second". If you pluck a guitar string, it initially moves down, then up, and then back down to its initial spot. If the time it takes for that motion is 1 second, we say it was vibrating at 1 Hertz. If it happened 2 times in 1 second (taking 1/2 second for each time), then it vibrated at 2 Hertz. If a cat can hear something vibrating at 10 Hertz, then that means it can hear a guitar string that went down-up-down 10 times in one second. For a human to hear it, it has to be twice as fast - 20 Hertz. Regarding your distance question, it turns out there is no set distance a cat, or any animal for that matter, can hear a sound. Whether our not you hear a sound depends on only on how loud it is and how far away from it you are. If something makes a soft sound, but you are right next to it, you will probably hear it. Once the sound moves away though, it spreads out more, and you won't. To hear that thing at the same distance, it needs to get louder. Hope this helps! - Isaac MJhari A hertz isn't a distance, A hertz is a range in pitch for hearing. You can get a feel about what pitch is by going to a piano and hit the farthest left key for the lowest pitch and the farthest right key for a high pitch sound. Ten hertz is a very low pitch on the scale of hearable sounds. The human ear can hear sounds from 20 Hertz to 20,000 Hertz (Audible Frequency). So if your DVM is telling you that your cat can hear sounds down to 10 Hertz, that means that your cat can hear low pitch sounds that humans can't hear. Sincere regards, Mike Stewart MJari, Auditory range is measured in terms of how a pitch sound you can hear compared with how low a pitch you can hear. High and low pitches are measured in terms of frequencies, which are measured in Hertz. A high-pitched noise is a higher frequency, or more Hertz. A low-pitch new has fewer Hertz. This range has nothing to do with distance. It about what kinds of noises you can hear, not how sensitively you can hear them. Hope this helps, Burr Click here to return to the Physics Archives

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