Types of Hearing Loss
The external ear and the middle ear conduct sound, and the inner ear receives the sound. A problem in the external or middle ear may result in a conductive hearing impairment. A problem in the inner ear may result in a sensorineural hearing impairment. Both types of problems may exist at the same time, resulting in a mixed hearing impairment.
A conductive hearing impairment may result from blockage of the external ear canal, from a hole in the eardrum, from middle ear infection or from disease of any of the three middle ear bones. A conductive hearing impairment can often be corrected medically. If not, a hearing aid is often useful.
A sensorineural hearing impairment may result from damage to the nerve endings in the inner ear. The damage can occur because of a lack of blood circulation, or change in the fluid pressure in the inner ear. Physical damage to the nerve endings from intense noise or drugs is also common. The most common cause of sensorineural hearing impairment is a change in the nerve endings as the result of aging. This type of impairment is not correctable with surgery or medicine, but can often be helped with hearing aids.
If have a hearing loss much greater in one ear, or if you are suffering from dizziness, your physician may order a Cat Scan to rule out a serious problem. Permanent sensorineural hearing loss could result from constant exposure to intense noise. Thousands of workers are exposed the noise each day. These individuals should wear hearing protection.
Also, playing and listening to loud music can cause a sensorineural hearing loss. Musicians who play their music several hours each week are often at risk for hearing loss. It is important to remember that it is not only rock musicians who are at risk. Symphony orchestra musicians are also at risk. Special ear plugs are available for musicians to protect their hearing while performing. Musician's ear plugs use special filters developed at Etymotic Research. The special ear plugs are designed to bring 
the level of the music down to a safe level while maintaining good music quality for the musician. The ear plugs are custom fit. Ear impressions are taken of the musician's ears, and the Etymotic filters are fitted into the ear mold. There are different filters with different attenuation values. An audiologist will help determine which filter the musician should use.