The human ear is most sensitive in the range of …………… where it can hear a feeble sound.

1. 1000 Hz — 1500 Hz
2. 1500 Hz - 1800 Hz
3. 2000 Hz - 3000 Hz
4. 100 Hz - 500 Hz

The speed of ultrasound in air is :

1. the same as audible sound
2. less than audible sound
3. more than audible sound
4. equal to the speed of light

Elephants produce ……………sound :

1. ultrasonic
2. infrasonic
3. supersonic
4. none of the above

…………… can hear the highest frequency range of sound.

1. Whales
2. Dogs
3. Cats
4. Bats