Question

The sounds having frequency less than 20 Hz are called ultrasonics.

• A. True
• B. False

Answer 1

The correct option is B False

Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear.

so the answer is B.