The human perception of sound intensity is known as the pitch of the sound. The pitch of the sound is created by the frequency of the sound waves that enter the ear. Human ears have the ability to hear sound frequencies between 20 hertz to 20,000 hertz.
Sound is propagated through the atmosphere in waves. The speed of sound depends on the medium in which the waves are formed. Sound waves travel fastest through solid media and slowest in gaseous media. The intensity of a sound wave is defined as the power of the wave divided by the area that the sound wave traverses. It can also be described as the amplitude of the sound wave. Sound intensity can be heard by the human ear in the form of pitch, which is related to sound frequency.
The human ear is made up of the outer, middle and inner ear. Sound waves enter the outer ear and hit the eardrum. The eardrum vibrates and transfers the energy of the sound wave to the middle ear. The bones of the middle ear vibrate and transmit the sound energy to the inner ear’s semicircular canals: the cochlea and the auditory nerve. Small hairs in the cochlea vibrate in response to the sound energy, and the vibrations transmit electrical impulses to the auditory nerve. These electrical impulses are sent to the brain, and they are understood as sound.