Question

The general range of audible frequencies for human is-
1. 24 Hz to 25,000 Hz
2. 20 Hz to 20,000 Hz
3. 26 Hz to 28,000 Hz
4. 10 Hz to 25,000 Hz

Answer 1

Correct Answer - Option 2 : 20 Hz to 20,000 Hz

Explanation:

Sound: A sound is a form of energy that produces the sensation of hearing in our ears.

• When a source of sound vibrates, it creates a disturbance in the medium. The particles of the medium vibrate in their mean position to transfer this disturbance.
• So, the particles move forward and backward about their mean position, creating regions of compression and rarefaction.
• Hence, a sound wave travels in a series of compression and rarefactions.
• Due to this nature of the transfer of sound energy, sound always requires a medium to propagate.
• Depending on the frequency of sound waves, they are classified as follows:

Audible sound	This is the type of sound that humans can hear. It lies in the frequency range of 20 Hz to 20 kHz.
Ultrasonic sound	This is the type of sound with frequencies higher than the audible range of human hearing. The frequency range of ultrasonic sound is > 20 kHz.
Infrasonic sound	This is the type of sound with frequencies lower than the audible range of human hearing. The frequency range of infrasonic sound is < 20 Hz.

The particles of a medium move forward and backward to create regions of compression and rarefaction. This is parallel to the direction of the sound wave.

• Audible sound waves have a frequency range of 20 to 20 kHz.
• Sound waves require a medium to travel. A vacuum is the absence of matter i.e. there will be no particles present in it to propagate sound. So, the sound does not travel in a vacuum.