Range of hearing

ABOUT RANGE OF HEARING

The human ear is able to hear sound in a frequency range of about 20Hz to 20kHz. We can not hear sounds of frequencies less than 20Hz or more than 20kHz, these limits vary from person to person and with age. Children can hear sounds of somewhat higher frequencies, say upto 30 kHz. With age, our ability to hear high frequency sound diminishes. For the elders, the upper limit often falls to 10-12 kHz. We take 20Hz-20 kHz as the audible range for an average person.

Even in the audible range the human ear is not equally sensitive for all frequency. It is most sensitive to frequencies around 2000-3000 Hz.

Sound of frequencies less than 20 Hz is known as infrasonic sound or infrasound. Sound of frequency greater than 20kHz is known as ultrasonic or ultrasound.

Different animals have different ranges of audible frequencies. A dog can hear sounds of frequencies upto about 50 kHz and a bat upto about 100 kHz. Dolphins can hear sounds of even higher frequencies. Animals such as elephants and whales can hear sounds of frequencies less than 20 Hz. Some fishes can hear sounds of frequencies as low as 1-25 Hz.NCERT solutions for class 8 Science prepared by Physics Wallah will help you to solve your NCERT text book exercise. 

Further Reading : 

1. Hearing Impairment

2. Echo

3. Noise