Hearing problems; see also Otitis Media and Tinnitus

• The human ear is designed to pick up a wide range of acoustic stimuli from the environment, process it, and transfer it via specialized neurons (nerve cells) to our brain, where it is analyzed into what we perceive as sound.
• Our ability to hear sounds over time may diminish as a result of use and abuse, trauma (ear drum perforation), or injury to the ear (e.g., infections).
• The ear is composed of 3 parts: the outer, the middle, and inner ear.  The outer ear consists of the pinna and the ear canal.
• From the pinna, sound enters the ear canal and hits the eardrum (separating the outer ear from the middle ear), which increases the volume of certain pitches. 
• Transmitting sound across the middle ear to the inner ear are three tiny bones, ossicles, of the middle ear, shaped like a hammer, anvil, and stirrup.  The ossicles pass and amplify vibrations from the eardrum to the cochlea (a structure shaped like a snail's shell) which is a part of the inner ear.
• After reaching the cochlea, vibrations set tiny hair cells in motion, which transform the vibrations into electrical signals that are picked up by the acoustic nerve and transmitted to the brain.
• The eustachian tube connects the nose and throat to the middle ear.  Consequently, allergies, throat infection, and sinus problems may have an adverse effect on the middle ear function as well.
• If there is damage to the ear canal or the middle ear (e.g., wax build-up, perforated eardrum, damaged ossicles), sound cannot travel to the cochlea, causing what is known as conductive hearing loss.
• Sensorineural hearing loss occurs most commonly as a result of damage to or aging of the inner ear structures.
• Exposure to loud sounds can damage the hair cells and interfere with the normal transmission of nerve impulses to the brain and hearing, especially in occupations involving prolonged exposure to high decibel pollution (e.g., factory workers, rock and roll musicians, explosives experts, etc.).
• Hair cells can also be affected by infection (e.g., viral) or as the result of normal aging. With this type of hearing loss, our ability to discriminate between sounds is affected and the conversation of others will be difficult to understand.
• Mixed hearing loss is caused by both conductive and sensorineural impairments.
• Any type of hearing loss needs an evaluation by an ENT (Ear, Nose, and Throat) physician, and testing by an audiologist.