Question

Complete the following sentences :

(a) An average person can hear sound of frequencies in the range ___ to ___.

(b) Ultrasound is of frequency ___ .

(c) Infrasonic sound is of frequency ___ .

(d) Bats can produce and hear ___ sound.

(e) Elephants produce ___ sound.

Answer 1

(a) 20 Hz, 20 kHz
(b) above 20 kHz
(c) below 20 Hz
(d) ultrasonic
(e) infrasonic