Sounds of which frequencies are called infrasonic sounds or infrasound?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Below 20 Hz
The human ear hears sounds between about 20 Hz and 20,000 Hz. Vibrations of frequency below 20 Hz are called infrasonic, or infrasound, and cannot be heard.
Earthquakes, whales and rhinoceroses produce infrasound, and sounds above 20,000 Hz are called ultrasonic, used in medical imaging and by bats and dolphins.