Saturday, July 17, 2010

Exploring Your Frequency Response Curve

An average young person can hear a staggering range of sound vibrations from 20 Hz to 20,000 Hz. (A Hertz is one vibration per second. So 20,000 Hz is a vibration that happens 20,000 times each second.) Of course, you won’t hear all pitches equally well. The middle-range pitches are the easiest to detect. A sound that’s similarly loud but extremely high-pitched will seem much quieter to your ear. You’ll notice a similar fall-off as you descend to the rumbles of low-frequency sound, although you’ll begin to feel them reverberate through your body.

As you age, the upper range of your hearing shrinks. For example, the hearing of a normal, middle-aged adult tops out at a significantly lower (but still impressive) 14,000 Hz. This change has been used to some effect by clever people on both sides of the age divide. For example, one company sells a sound device called the Mosquito Ultrasonic Teen Repellent ( It emits an annoying sound that only young people can hear. Put it in a place where you don’t want crowds of teenagers to loiter—say, a mall parking lot—and it’s sure to drive them away. A similarly inventive product is the Teen Buzz ringtone ( Teenagers use it to announce text messages on their cell phones without alerting teachers and other authority figures in the over-30 crowd.

To test your own hearing and find the highest frequency you can detect, try an online hearing test (like the one on Of course, these tests depend on some factors you can’t control, such as the quality of your speakers and the noise your computer makes, so they’re not perfectly accurate.

Source of Information : Oreilly - Your Body Missing Manual

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