Hearing loss is the third most frequently reported chronic medical condition in America. Hearing loss occurs to most people as they age. get exposed to loud noise, use certain medications, suffer infections, head or ear trauma. A few have congenital (birth or prenatal) or hereditary causes. Surprisingly hearing loss is the single most common birth "defect" in America. 30 million people in the USA have some degree of hearing loss.

If you have any of these symptoms, you should consider seeing an audiologist:

You frequently ask people to repeat what they said.

You often miss a good part of was is being said.

You frequently complain that people mumble.

You play the TV or radio louder than your friends, spouse and relatives.

You find that looking at people when they speak makes it easier to understand.

Do you get in arguments,  because you thought they said one thing, and they say they said another?

Do you have difficulty understanding some voices and words on the phone?

Do you have a history of noise exposure at work or at concerts.

Do you get frustrated easily with unfamiliar and soft voices?

Do you often ''fake it'' by nodding in agreement, even though you weren’t sure what was said?

Do you have difficulty hearing the words at large meetings?

Do you have difficulty determining where the sounds are coming from?

Do one ear hear better than the other?

Do you have difficulty understanding when there are more than two people talking at the same time?

What can cause hearing loss?

There are several factors that can cause hearing loss which we will can take a look in depth:

Loud Music

Have you ever been to a concert and had trouble hearing for the days following that?  This is becoming more and more frequent, we are talking about temporary hearing loss.  But those damages the ear in the long run an can eventually cause permanent hearing loss.  The musicians are one of the groups most exposed to prolonged and intense noise and should be protecting their ears.  Sound levels at a concert are in the range of 120 to 140 db, that is 20 to 40 db too loud.  The threshold of the human ear normally is around 85 to 100 db.  Sounds above that will damage the fragile tissues strands in the cochlea an lead to hearing loss.  There are several ways to protect your ears such as earplugs when going to concerts, clubs, and noisy environment.

Conductive

This occurs when the sound is not conducted normally through the outer or middle ear.  Conductive hearing loss is only mild and can't be worse than a moderate impairment.  This can be caused by an obstructed ear canal, tympanic membrane ossicles innner ear abnormalities or a superior canal dehiscence syndrome.

Sensorineural hearing loss

A sensorineural hearing loss is due to insensitivity of the inner ear, the cochlea, or to impairment of function in the auditory nervous system.  This can be from mild to the point of total deafness.  Most sensory hearing loss is due to poor hair cell function. The hair cells may be abnormal at birth, or damaged during the lifetime of an individual. There are both external causes of damage, like noise trauma and infection, and intrinsic abnormalities, like deafness genes.  Abnormalities of the auditory system that causes sensorineural hearing loss is called Central Hearing Impairment. 

Long-term exposure to environmental noise

Different lifestyles can make a huge difference in the health of your hearing.  People exposed to daily noise can, over time, degrade hearing.  Louder sounds cause damage in a shorter period of time. Estimation of a "safe" duration of exposure is possible using an exchange rate of 3 dB. As 3 dB represents a doubling of intensity of sound, duration of exposure must be cut in half to maintain the same energy dose. For example, the "safe" daily exposure amount at 85 dB A, known as an exposure action value, is 8 hours, while the "safe" exposure at 91 dB(A) is only 2 hours (National Institute for Occupational Safety and Health, 1998).

For some people, sound may be damaging at even lower levels than 85 dB A. Exposition to pesticides, some medications including chemotherapy and solvents can lead to greater susceptibility to noise damage, as well as causing their own damage.  There are some environments that are not regulated, such as sports arenas, musical venues and bars. 

Most people are unaware of the presence of environmental sound at damaging levels, or of the level at which sound becomes harmful. Common sources of damaging noise levels include car stereos, children's toys, transportation, crowds, lawn and maintenance equipment, power tools, gun use, and even hair dryers. Noise damage is cumulative; all sources of damage must be considered to assess risk. If one is exposed to loud sound (including music) at high levels or for extended durations (85 dB A or greater), then hearing impairment will occur. Sound levels increase with proximity; as the source is brought closer to the ear, the sound level increases. This is why music is more likely to cause damage at the same output when listened to through headphones, as the headphones are in closer proximity to the ear drum than a loudspeaker.

Genetic

Hearing loss can be inherited. Both dominant gene and recessive genes exist which can cause mild to profound impairment.  You have more chances to be impaired if some of your relatives suffer from hearing loss or disorders. 

Disease or illness

• Measles may result in auditory nerve damage

• Meningitis may damage the auditory nerve or the cochlea

• Autoimmune disease has only recently been recognized as a potential cause for cochlear damage. Although probably rare, it is possible for autoimmune processes to target the cochlea specifically, without symptoms affecting other organs.

• Mumps (Epidemic parotitis) may result in profound sensorineural hearing loss(90 Decibel|dB or more), unilateral (one ear) or bilateral (both ears).

• Presbycusis is a progressive hearing impairment accompanying age, typically affecting sensitivity to higher frequencies (above about 2 kHz).

• Adenoids that do not disappear by adolescence may continue to grow and may obstruct the Eustachian tube, causing conductive hearing impairment and nasal infections that can spread to the middle ear.

• AIDS and AIDS-related complex|ARC patients frequently experience auditory system anomalies.

• HIV (and subsequent opportunistic infections) may directly affect the cochlea and central auditory system.

• Chlamydia may cause hearing loss in newborns to whom the disease has been passed at birth.

• Fetal alcohol syndrome is reported to cause hearing loss in up to 64% of infants born to alcoholism|alcoholic mothers, from the ototoxic effect on the developing fetus plus malnutrition during pregnancy from the excess ethanol|alcohol intake.

• Premature birth results in sensorineural hearing loss approximately 5% of the time.

• Syphilis is commonly transmitted from pregnant women to their fetuses, and about a third of the infected children will eventually become deaf.

• Otosclerosis is a hardening of the stapes (or stirrup) in the middle ear and causes conductive hearing loss.

• Superior canal dehiscence, a gap in the bone cover above the inner ear, can lead to low-frequency conductive hearing loss, autophony and vertigo

Medications

Some medications cause irreversible damage to the ear, and are limited in their use for this reason. Various other medications may reversibly affect hearing.

Physical trauma

• There can be damage either to the ear itself or to the brain centers that process the aural information conveyed by the ears.

• People who sustain head injury are especially vulnerable to hearing loss, either temporary or permanent.

• Exposure to very loud noise (90 dB or more, such as jet engines at close range) can cause progressive hearing loss. Exposure to a single event of extremely loud noise (such as explosions) can also cause temporary or permanent hearing loss. A typical source of acoustic trauma is an excessively loud music concert.