Question

The sound waves which cannot be heard by a human ear are called.

• A. Ultrasonic sounds
• B. Infrasonic sounds
• C. Extraordinary sounds
• D. Both (a) and (c)

Answer 1

The correct option is D Both (a) and (c)

Human ear has a hearing range of 20Hz to 20KHz.

Ultrasonic and Extraordinary sounds are out of this range but infrasonic sound is near to 20 Hz and can be heard by humans but with difficulty.