Causes of Permanent Hearing Loss

As we all know, ear is an important sensory organ, responsible for receiving sound waves. There are three major parts in an ear viz. outer, middle and inner ear. Each of these plays an important role in the normal functioning of the ear. Even a mild damage in any of the ear parts can cause ear problems and hearing loss.

Hearing loss is a partial or total inability to perceive sound waves. Hearing loss can be temporary or permanent; temporary hearing loss can be treated with medications and surgical methods, whereas permanent hearing loss cannot be treated. There are basically three types of hearing loss:

• Conductive hearing loss - It is caused due to problems in, either the middle ear or the outer ear. In such a condition, sound is not transmitted into the inner ear and the person hear faint voices that he/she finds it difficult to understand.
• Sensorineural hearing loss - It is caused due nerve damage in the inner ear. Thus, proper signal is not transmitted to the brain and the person experiences problems in hearing.
• Mixed - In mixed type, both conductive and sensorineural are responsible for causing hearing loss.

Causes of Permanent Hearing Loss

Permanent hearing loss can be caused due to many reasons. It can be gradual, for e.g., age-related hearing loss (presbyacusis) or sudden hearing loss, for e.g., viral infection. It is a fact that sensorineural disorder results in permanent hearing loss, whereas a conductive hearing loss may be temporary or permanent. Let's take a look at the causes of permanent hearing loss.

• Exposure to extremely loud noise (more than 90 decibels), also referred to as noise-induced hearing loss (NIHL)
• Injury to the ear or head
• Trauma that includes puncture of the eardrum with the use of foreign objects and temporal bone fracture
• Otosclerosis (a condition of bony growth on the ossicles of middle ear, making them less mobile)
• Middle ear infection by virus and/or bacteria
• Bacterial infection like meningitis, which affects the auditory nerve
• Overuse of certain drugs such as salicylates, aminoglycoside antibiotics and chemotherapy drugs
• Meniere's disease, which affects the inner ear
• Neurological disorders (e.g. stroke, multiple sclerosis)
• Acoustic neuroma (non-cancerous tumor that affects auditory system)

A major cause of permanent hearing loss in premature babies is use of antibiotics for treatment of infection. According to a study conducted by genetic researchers at the Institute of Child Health in London, it was revealed that use of potent antibiotics in those children who have an inherited sensitivity towards antibiotics, may cause ear damage (otoxicity) and permanent deafness.

Permanent hearing loss may or may not be associated with tinnitus (persistent ringing of the ear). Diagnosis of permanent hearing loss is done based on physical examination and hearing tests such as whispered speech tests, tuning fork test and pure tone audiometry.

After confirmation of permanent hearing loss, the doctor may prescribed use of hearing aids, assistive listening devices or other communication aids. If you happen to stay in a noisy environment, it is always advisable to protect from the undesirable noise by using earplugs or other auditory protective devices. Well! Precaution is always better than cure.