What is sensorineural hearing loss?
Sensorineural hearing loss occurs when the inner ear or hearing nerve is damaged or unable to process sound as intended. This type of hearing loss can be acquired or genetic and can affect people of all ages.
The inner ear and hearing nerve are responsible for delivering a high-resolution signal to the brain for processing. When the inner ear is damaged, the sound's resolution reduces, making the sound not only quieter but less precise. It can also result in a decreased tolerance for louder sounds making them quickly uncomfortable.
If you would like to better understand how hearing works, please head over to the article about hearing loss.
The degrees of sensorineural hearing loss
The degree of sensorineural hearing loss is a description of the severity of hearing loss you may have. The severity falls into one of five categories:
mild hearing loss: 26 to 40 dB HL
- moderate hearing loss: 41 to 55 dB HL
- moderate-to-severe hearing loss: 56 to 70 dB HL
- severe hearing loss: 71 to 90 dB HL
- profound hearing loss: 91 to 100 dB HL.
The higher the level, the greater the hearing loss and the more significant the impact on your hearing ability.
What do the categories mean in daily life?
- Mild hearing loss: Many of the soft daily sounds fall into this level and could be missed by someone with a mild hearing loss. Soft daily sounds include people breathing, leaves rustling, people whispering, refrigerator humming, cat purring and dripping of water. Although people with mild hearing loss can communicate well in quiet surroundings, in situations with background noise there could be word confusion for words starting with certain consonants (“s”, “f” or “th”).
- Moderate hearing loss: People with moderate hearing loss will have more difficulty hearing and understanding speech at normal conversations levels. Following a conversation will require more effort and many of the words could be missed or misunderstood even in quiet. It may not be possible to follow a conversation at normal levels in background noise. Other sounds that could be missed include laughter, rain falling and coffee brewing.
- Moderate-to-severe hearing loss: People with moderate-to-severe hearing loss will have difficulty understanding speech in most situations and have even more difficulty in noise. The TV or radio are not understandable at normal levels and require louder volume levels to be understood. Other daily sounds that could be missed include water running, an alarm clock, children playing, a busy street, an electric toothbrush and a washing machine.
- Severe hearing loss: People with this hearing loss will have difficulty with most conversations at normal and moderately loud levels. Speech at loud levels might be understood as long as there is no competing background noise. Other daily sounds that could be missed include a doorbell or telephone, traffic noise, a vacuum cleaner, a toilet flushing, and people working or various office sounds.
- Profound hearing loss: People with this hearing loss can only hear very loud sounds such as a lawn mower, a motorcycle, an ambulance siren or a blender. Speech at normal levels would not be heard and even when shouting, the speech might not be audible or understood. Those with profound hearing loss are generally candidates for cochlear implants or may rely on sign language or lip-reading to help them understand speech.
What are the symptoms of sensorineural hearing loss?
If you have sensorineural hearing loss, you may experience one or more of the following:
- you may have difficulty understanding or hearing speech when there is background noise (e.g., at a restaurant or café)
- you can feel that people mumble or that sounds are not sharp
- others may complain that the TV is too loud
- you may experience ringing in your ears
- you find yourself often having to ask ‘What?’ or have others repeat themselves frequently
- you have trouble understanding people on the phone
- others notice that you do not hear well.
If you are experiencing any of these symptoms, you should have your hearing tested by your hearing care specialist. Before you book an appointment, you can check your hearing with an online hearing test.
What causes sensorineural hearing loss?
Sensorineural hearing loss can occur for various reasons. The most common causes of sensorineural hearing loss fall into the category of acquired hearing loss.
What does acquired hearing loss mean?
Acquired hearing loss means that hearing loss happens after birth and during your life.
The causes of sensorineural hearing loss can include:
Presbycusis or age-related hearing loss. This hearing loss occurs gradually over time as we get older. As the change happens gradually it can take longer to recognize the hearing loss.
- Noise-induced hearing loss. Noise, when heard or played at high levels, can damage your ears. Depending on the level of sound and the length of time you experience it, it can cause temporary or permanent damage to your hearing. Some causes of noise-induced hearing loss include live concerts, listening to high levels with headphones, shooting/hunting, power tools or equipment, motorcycling/snowmobiling, or working in noisy places (construction work, café/restaurant).
- Trauma. Head trauma or acoustic trauma can cause permanent hearing loss. Head trauma can come from any accident which involves a blow to the head (e.g., car accident, bike accident, falling, etc.). Acoustic trauma occurs due to an excessively loud sound such as an explosion. The damage caused by acoustic trauma can include structural damage to the inner ear as well as noise-induced hearing loss.
- Sudden sensorineural hearing loss. Sudden sensorineural hearing loss is a category of hearing loss defined by hearing loss that occurs from one moment to the next such as waking up with hearing loss. There are some known causes of sudden loss, such as a viral infection, trauma, or diseases, but sometimes no reason can be found.
- Health factors. Several health factors can increase the likelihood of acquiring hearing loss. These factors can include diabetes, obesity, smoking, or high blood pressure.
What are other potential causes of sensorineural hearing loss?
Sensorineural hearing loss can also occur due to genetics or other causes.
These can include:
Genetic disorders. Many disorders can have hearing loss as part of the disorder (e.g., Waardenburg syndrome, Usher syndrome).
- Hereditary. Hearing loss can be hereditary. It is a good idea to monitor your hearing if you have a family history of hearing loss.
- Congenital disorders. Congenital means that something is present at birth. Babies can be born with genetic, hereditary, or other medically related causes of hearing loss such as ear malformations.
How to treat sensorineural hearing loss
The most common devices used to treat permanent sensorineural hearing loss are hearing aids. They are small electronic devices worn behind or in the ear which amplify sound to make it louder and more precise. They are programmed to your specific hearing loss to provide each person an individualized sound.
To learn more about the different hearing aids and options, see this article on hearing aids. Your hearing care specialist can help you select the best hearing aid for your needs.
Other implantable devices called cochlear implants can be used to treat sensorineural hearing loss. Cochlear implants deliver sound to the ear by electrically stimulating the hearing nerve with tiny electrical impulses.
It includes a small array implanted into the cochlear (inner ear organ) and a magnet embedded in the skull behind the ear. There is also an external receiver and hearing device. This is an option for those who have more significant hearing loss and receive little to no benefit from conventional hearing aids.
How can sensorineural hearing loss be prevented?
Sensorineural hearing loss can get worse over time. If your hearing loss is hereditary, it will make it harder to avoid. However, there are several things we can do that can help reduce or prevent further damage to our hearing.
Protect your hearing with hearing protection. Loud sound and noise can cause hearing loss. Wearing hearing protection when taking part in noisy activities, such as concerts, shooting, motorcycling, car races, etc., will reduce the sound to safer levels. There are many types of hearing protection such as earplugs and earmuffs. A hearing care specialist can explain the options and help you find which hearing protection works best for your lifestyle.
- Turn the volume down. When listening to music or other sounds via radio, streaming, or some other audio device, it is crucial to keep the volume set at safe levels. Some audio devices allow you to set max limits for the volume. If you find you turn up your music because it is noisy, you can try noise-canceling headphones instead.
- Have your hearing regularly tested to monitor for hearing loss or changes in hearing. An online hearing test can be an easy way to monitor any changes to your hearing and can indicate if you should schedule a comprehensive hearing test.
- Monitor your medication. Some medications can potentially be harmful to your hearing. These are called ototoxic medications. If you are on such medication, it is crucial to monitor your hearing frequently for any changes. If possible, check with your physician about possible options that are not ototoxic.