Sensorineural hearing loss is caused by damage to the cochlea in the inner ear or damage to the nerve pathways from the inner ear to the brain. Sensorineural hearing loss is the most common type of permanent hearing loss.
Note:Sudden sensorineural hearing loss (SSHL), also called sudden deafness, is a rapid loss of hearing. This can happen to a person all at once or over a period of up to three days. It should be considered a medical emergency and a patient who experiences SSHL should visit a doctor immediately. If it’s treated in a timely manner, some SSHL patients recover completely without treatment and often within the first few days. Others may get better slowly over a period of 1-2 weeks.
Causes & Risk Factors
There are several causes of sensorineural hearing loss including:
Aging
Genetics
Illnesses
Drugs that are toxic
Head trauma
Malformation of the inner ear
Exposure to loud noise
Symptoms
With sensorineural hearing loss, the ability to hear sounds is reduced. In some cases, even when speech is loud enough to hear, it may still sound unclear or muffled.
Treatment Options
Treatment options for people with sensorineural hearing loss include the use of devices like hearing aids and cochlear implants. Hearing aids can turn up the volume and also provide sound so that understanding speech is no longer as difficult. 95% of sensorineural hearing loss cases can be helped by hearing aids.
Cochlear implants, and now hybrid cochlear implants, provide direct electrical stimulation to the auditory nerve in the inner ear. Children and adults with a moderately-severe to profound hearing loss who cannot be helped by hearing aids may be candidates for cochlear implants.
Prevention
According to the National Institute on Deafness and Other Communication Disorders (NIDCD), approximately 4,000 new cases of sensorineural hearing loss occur each year in the United States. It can affect anyone, but it typically occurs in people 30-60 years of age.
Sensorineural hearing loss should be addressed with hearing aids as soon as possible. This helps slow its progression. Another simple way to prevent further damage is to limit or avoid noise exposure. If you work in a noisy environment or plan on attending a concert or other event with high volume levels, then ear protection is critical.
Conductive hearing loss occurs when sound cannot be transmitted, or conducted, throughout the hearing mechanism of the outer and middle ear to reach the inner ear.
Causes & Risk Factors
There are several causes of conductive hearing loss including:
Buildup of earwax or impacted earwax
Fluid in the middle ear from illness
Ear infections
Allergies
Perforated eardrum
Trauma to the eardrum or middle ear bones
Congenital/genetic stiffness of the middle ear bones
Other anomalies of the middle ear
Symptoms
Conductive hearing loss usually involves a reduction in sound level, limiting your ability to hear faint sounds. It does not make sounds more difficult to understand or interrupt speech comprehension.
Treatment Options
If the conductive loss is being caused by a blockage in the ear canal, removing it can often restore some or all hearing ability. Otherwise, this type of hearing loss can often be corrected by medical and/or surgical intervention. If medical intervention is not an option, conductive hearing loss can also be corrected by the use of hearing aids.
Prevention
Keep your ears clean and dry, but don’t use cotton swabs to do so. Read more about taking care of your ears and hearing ability here.
Just like it sounds, mixed hearing loss is a combination of conductive hearing loss and sensorineural hearing loss. It therefore occurs when there is damage or a blockage in the outer or middle ear as well as damage to the cochlea or auditory nerve in the inner ear.
Causes & Risk Factors
There are several causes of mixed hearing loss including:
Those for sensorineural hearing loss:
Aging
Genetics
Illnesses
Drugs that are toxic
Head trauma
Malformation of the inner ear
Exposure to loud noise
Those for conductive hearing loss:
Buildup of earwax or impacted earwax
Fluid in the middle ear from illness
Ear infections
Allergies
Perforated eardrum
Symptoms
With sensorineural hearing loss, the ability to hear sounds is reduced. Even when speech is loud enough to hear, it may still sound unclear or muffled. Conductive hearing loss usually involves only a reduction in sound level, limiting your ability to hear faint sounds but not making them more difficult to understand. Mixed hearing loss, therefore, will include symptoms from both of these types.
Treatment Options
The conductive part of mixed hearing loss can often be corrected with medical or surgical treatment, but the sensorineural part cannot be reversed. However, hearing aids can make a big difference!
Hearing aids are particularly useful in improving hearing and speech comprehension for people with sensorineural hearing loss. When recommending a hearing aid, your hearing healthcare professional will consider your hearing ability, activity level, physical limitations, medical conditions, cosmetic preferences, and other lifestyle needs.
Prevention
The simplest way to prevent further damage is to limit or avoid noise exposure and take good care of your ears.
Noise-induced hearing loss (NIHL) affects children, teenagers, and adults who are exposed to harmful noises. It can happen after only one time of being around an intense "impulse" sound, such as an explosion, or it can occur as a result of continuous exposure to loud sounds over time. Depending on the environment and incident, a single exposure can cause a temporary decrease in hearing by damaging the hair cells in the inner ear. On occasion, the chemicals in the inner ear can add nutrients to the hair cells and repair them after a while, thereby returning hearing. However, repeated exposure to loud sounds without appropriate hearing protection can permanently damage these hair cells and cause a lasting decrease in hearing.
According to the NIDCD, approximately 1.1 billion teenagers and young adults are at risk for NIHL due to unsafe listening practices. These include the use of headphones or earbuds at damaging volumes and the failure to protect your ears at concerts, bars, and other loud places.
Causes & Risk Factors
Recreational activities that may be risk factors include target shooting and hunting, snowmobile riding, woodworking and other hobbies, playing in a band, attending rock concerts, and listening with headphones too loudly. Harmful noises at home may also come from lawnmowers, leaf blowers, and shop tools.
Damaging noise levels in work environments are also a growing concern. The Centers for Disease Control and Prevention recently reported that occupational hearing loss is the most common work-related injury in the United States. Approximately 22 million U.S. workers are exposed to hazardous noise levels at work, and an additional 9 million are exposed to ototoxic chemicals (chemicals that result in hearing loss). An estimated $242 million is spent annually on workers' compensation for hearing loss disability. The National Institute for Occupational Safety and Health (NIOSH) recommends removing hazardous noise from the workplace whenever possible and using hearing protection in situations where dangerous exposure to noise have not yet been controlled or eliminated.
Symptoms
Decreased hearing can occur when a person is exposed to loud noise, this can happen with a single incident as well as from repeated exposure over a long period of time. Sounds may become distorted or muffled, and it may be difficult to understand speech. People with noise-induced hearing loss may not even be aware of the loss, but it can be detected with a hearing test.
Excessive noise exposure can also cause tinnitus, a condition which causes you to hear a ringing or other sound when no external sound is present.
Treatment Options
Hearing aids are almost always an appropriate way to address NIHL, and many can help manage tinnitus symptoms as well. Make an appointment with your local professional to see if hearing aids are right for you.
Prevention
Wear earplugs when noises reach dangerous levels.
Follow the 60/60 rule: When you listen to music with a personal audio device, listen at no louder than 60% volume for no more than 60 minutes a day.
Choose over-the-ear headphones, as they don't sit in the ear canal or as close to the eardrum.
Take advantage of smartphone apps that monitor the volume level of your smartphone for you.
Consider musicians' earplugs in order to attend concerts without sacrificing sound quality.
When you're around loud noise, try to give your ears a break from the noise every so often.
Give your ears time to recover. Research suggests that you need 18 hours of quiet after a night out in order to truly let your ears recuperate.
