- Books Name
- Science Made Easy Science Book
- Science Made Easy
- CBSE Class 9
Range of Hearing
(i) Range of hearing in human is 20 Hz to 20000 Hz.
→ Children younger than 5 years and dogs can hear upto 25 Khz.
(ii) The sounds of frequencies lower than 20 Hz are
known as ‘infrasonic sounds’
→ A vibrating simple pendulum produces infrasonic sounds.
→ Rhinoceroses communicate each other using frequencies as low as 5 Hz.
→ Elephants and whales produces infrasonic waves.
→ Earthquakes produces infrasonic waves (before shock waves)
which some animals can hear and get disturbed.
(iii) The sounds of frequencies higher than 20 KHz are known as ‘ultrasonic waves’.
→ Dogs, parpoises, dolphins, bats and rats can hear ultrasonic sounds.
→ Bats and rats can produce ultrasonic sounds.