Question

Ear is most sensitive to sound waves of:
A. 1000 cycles/sec
B. 10000 cycles/sec
C. 6000 cycles/sec
D. 20 cycles/sec

Answer 1

Hint: One can easily recognise objects in the world by hearing the sound they produce. The sound waves produced from the vibrating objects reach the outer ear pinna which causes the eardrum to vibrate and initiate the processing of hearing. Frequency, amplitude and temporal variation are the three physical attributes of a sound waveform.

Complete Step by Step Answer:
Frequency refers to the cycles per second of the period oscillation. It is measured in hertz (Hz), sound pressure is referred to as amplitude and temporal variation of sound is referred to as sound duration. If the pressure variations or sound waves in the air are in the audible frequency range of 20Hz - 20KHz, the human ear can respond to these frequencies and initiate the processing that enables us to hear. Our human ear is capable of detecting pressure variations of less than one billionth of atmospheric pressure. The hertz (Hz) is defined as the cycles per second of a periodic oscillation. Now, 20Hz means 20 cycles per second and 20 KHz means 20000 cycles per second. This is the range of frequency which our ear is able to detect and forms the absolute border of hearing. The auricle (pinna) which is the visible part of the outer ear and is most sensitive to the sound waves of frequency 2000 Hz - 5000 Hz.

Thus, the correct answer is option A:- 1000 cycles per second.

Note: The hearing range of human beings depends on pitch (high or low) and the loudness of the sound. Hertz is used for measuring pitch whereas decibel (dB) is used for measuring loudness. A normal person can typically start hearing at 0 dB. Prolonged exposure to loudness of the sound that is more than 85dB can cause serious hearing problems and even hearing impairment.