The purpose of the human ear is to convert sound waves into nerve impulses, then the brain perceives these impulses as sounds. The human ear can perceive sound in the range of 20 to 20,000 Hz. Three distinct areas in the human ear that are responsible for the process of the auditory system, the outer ear, the middle ear and the inner ear. First, the canals of the external ear pass sound waves through the ear canal to the eardrum. The eardrum is a thin membrane stretched across the inner end of the canal. The air pressure caused by the sound waves causes the eardrum to vibrate. Then, these vibrations are transmitted to three small bones called (Ossicles) found in the middle ear. The middle ear senses vibrations and transmits them to another thin membrane called (oval window) that separates the middle ear from the inner ear. The inner ear contains the (Cochlea), a spiral-shaped structure that contains the organ of the (Corti) which is located in a sensitive membrane called the (basilar membrane). Finally, when the vibrations arrive at the basilar membrane, small sensory hair cells within the Corti bend to stimulate the sending of nerve impulses to the brain (Steinmetz & Lee, n.d.). However, humans have the ability to hear higher sounds when underwater than when they can through the air. Hearing underwater would occur via bone conduction rather than the normal hearing pathway. Humans can hear between 20 and 20,000 hertz in the air, while they can hear around 200,000 hertz when submerged. Instead of using the normal channels of the auditory process, humans hear through bone conduction which bypasses the waves in the inner ear. Underwater sound comes through the mastoid, or bone behind the ear. In a study by NavalSubmarine Medic...... at the center of the article......y the mechanism of bone conduction. If this is the case, it appears that changes in the impedance characteristics of the middle ear mechanism should not affect the audible threshold underwater. Therefore, it is suggested that the bone conduction mechanism is, indeed, responsible for hearing underwater. Works Cited Goodwin, J. (May 24, 2011). Underwater, humans hear through their bones. Health day. Retrieved from http://consumer.healthday.com/bone-and-joint-information-4/bone-joint-and-tendonnews72/underwater-humans-hear-through-their-bones-653235.html Hollen,H.& Brandt, F. (March 3, 1969). Effect of air bubbles in the external ear canal on hearing thresholds underwater. Laboratory of Communication Sciences, University of Florida.Steinmetz,J. &Lee, G. (n.d.). Auditory system. Retrieved from http://www.hitl.washington.edu/scivw/EVE/III.A.2.Auditory.html