Hearing Loss

Causes of Hearing Loss

Hearing loss occurs to most people as they age. Research has clearly shown, hearing loss negatively impacts quality of life, overall health, personal and professional relationships, and your ability to communicate. It has been estimated that 90 to 95 percent of all cases of hearing loss can be corrected with hearing aids.

Hearing loss is the most common birth defect in America and is the third most common chronic ailment among older adults. Hearing loss can be caused by aging, noise exposure, ear infections, ototoxic medications, head or ear trauma, congenital or hereditary factors, disease and many other causes.

• Osteogenesis imprefecta
• Leopard syndrome (multiple lentigines)
• Robinson type ectodermal dysplasia
• Cockayne syndrome
• Bjorn pili torti and deafness syndrome
• Multiple synostosis syndrome
• Hunter syndrome
• Taybi oto-palato-digital syndrome
• Hereditary nephritis
• Mohr syndrome
• Hurler syndrome
• Waardenburg syndrome
• Kartagener syndrome
• Fronto-metaphyseal dysplasia syndrome
• Morquio syndrome
• Trisomy 13
• Multiple legtigines syndrome
• Treacher Collins syndrome
• Stickler syndrome

• Rubella syndrome
• Cengenital atresia of the external auditory canal
• Congenital crytomegalovirus
• Congenital perilymphatic fistula
• Fetal methyl mercury effects
• Fetal iodine deficiency effects

• Meningitis
• Mumps
• Measles
• Ear infection (otitis media)
• Scarlet fever

• Traumatic perforation of the eardrum
• Skull fracture (temporal bone)
• Acoustic trauma such as explosions, fireworks, gunfire, rock concerts, earphones
• Barotrauma

Toxic:

• Aminoglycoside antibiotic
• Ethacrynic acid – oral
• Aspirin
• Chloroquine
• Quinidine

• Age-related hearing loss (presbycusis)

• Any occupation with exposure to loud noises on a continuous day-to-day basis can result in hearing loss due to nerve end damage. Increased attention to conditions in the work environment has markedly decreased the likelihood of work-related hearing loss.

• Meniere’s disease
• Acoustic neuroma

• Build up of wax in the ear canal
• Foreign body lodged in the ear canal
• Injury to the head
• Allergy
• Blocked Eustachian tubes
• Scarred or perforated eardrum
• Ear infections (chronic otitis externa, chronic otitis media, malignant otitis externa)
• Reaction to medication such as aminoglycosides, chloroquine, quinidine

Common Types of Hearing Loss

Sensorineural hearing loss (SNHL) is the most common type of hearing loss. More than 90 percent of all hearing aid wearers have sensorineural hearing loss. The most common causes of sensorineural hearing loss are age related changes in hearing and noise exposure. People with sensorineural hearing loss typically report they can hear people speak, but can’t understand what they’re saying. People with sensorineural hearing loss often complain “everyone mumbles”. Also, they usually hear better in quiet environments and have difficulty understanding conversation over the telephone.

Conductive hearing loss occurs when sound waves are not conducted efficiently through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles bones), resulting in a reduction of loudness. Conductive hearing loss may result from earwax blocking the ear canal, fluid in the middle ear, middle ear infection, obstruction in the ear canal, perforations (hole) in the eardrum or problems with the middle ear bones. Patients with a conductive hearing loss should be referred to a physician for medical treatment prior to hearing amplification.

Mixed hearing loss is a sensorineural hearing loss combined with a conductive hearing loss. For example, a patient may have a noise induced hearing loss and a middle ear infection.

Degrees of Hearing Loss

Determining the degree of hearing loss can be difficult, particularly with young children who do not test as well as older people who can provide more accurate results. A hearing loss can be mild, moderate, severe or profound. Sounds below the lines on the audiogram can be heard.

Normal – Anything below 15 dB. All the X and O are above the 15dB line. This means hearing is ‘normal’. Slight – At 16dB to 25 dB, little difficulty understanding speech.
	Mild – At 26dB to 40 dB, a little difficulty hearing speech. Even a mild hearing loss can be serious for children still learning to talk.
Moderate – At 41dB to 55 dB, more difficulty hearing speech. Sounds below the lines on the audiogram can be heard. Low/loud sounds like oo, ah, ay and ee may be heard.   Moderately Severe – At 56dB to 70dB, a lot of difficulty hearing speech.
	Severe – At 71dB to 90 dB, serious difficulty hearing speech without hearing aids. Conversational speech cannot be heard. Shouting and loud noise (like traffic) can be heard.
Profound – Anything over 91 dB. With this level of hearing loss, hearing aids may or may not help; cochlear implants are often an option. Speech cannot be heard. Very loud noises like pneumatic drills and planes taking off can be heard (or felt). People with very profound hearing loses can feel loud low sounds.

Tinnitus

Tinnitus is the name for the common sensation of “ringing in the ears”. This is a common symptom in patients with hearing loss that can come and go or it can be constant. When it is constant or severe, it can be annoying and distracting. While it cannot be cured, there are options to help improve and manage the tinnitus.

Untreated Hearing loss

Untreated hearing loss can be frustrating and isolating to patients. According to a study by the National Council on Aging, people with untreated hearing loss were more likely to report depression and anxiety, and tended to participate less in social activities than those who obtain treatment for their hearing loss. However, according to the NCOA study, persons who seek out and receive treatment for their hearing loss will often report benefits that include better relationships with their families, better feelings about themselves, improved mental health and greater sense of independence and security.

Hearing Loss in Children

It is widely understood and accepted that hearing is critical for the development of speech, language, communication skills and learning. The earlier that hearing loss occurs in the child’s life, the more serious the effect on the child’s development. Similarly, the earlier the hearing loss is identified and intervention begun, the less serious the ultimate effects.

Infants can be evaluated and fit with amplification as early as 4 weeks old. Children at this age are usually evaluated by auditory brainstem response (ABR) and by otoacoustic emission (OAE) testing. A child as young as eight to twelve months old can be evaluated by means of behavioral observation or visual reinforcement audiometry. Once a child reaches two and a half to three years of age, play audiometry can be used for evaluation. By five years of age, traditional (raise your hand) audiometry is used. Recent research indicates that children identified with hearing loss who begin services before 6 months old will develop language (spoken or signed) on par with their hearing peers.

Symptoms of Hearing Loss in Children

• Your child is inconsistently responding to sound.
• Language and speech development is delayed.
• Speech is unclear.
• Sound is turned up on electronic equipment (radio, TV, CD or MP3 players, etc.).
• Your child does not follow directions.
• Your child often says “Huh?”.
• Your child does not respond when called.

Effects of Hearing Loss in Children

Delays in the development of receptive and expressive communication skills The language deficit causes learning problems that result in reduced academic achievement Communication difficulties often lead to social isolation and poor self-concept or depression It may have an impact on vocation choices