Question

The sound which is below the frequency of 20 Hz is called ___ .

Answer 1

Human beings are not able to hear all the sound that is produced. If the frequency of the vibration is less than 20 Hz or if the frequency of the vibration is more than 20,000 Hz, the sound is inaudible to humans. The sound which is below the frequency of 20 Hz is called infrasonic and the sound which has frequency more than 20,000 Hz is called ultrasonic.