Sensorineural hearing loss: Types, causes, and treatment Health ConditionsHealth ConditionsAlzheimer's & DementiaAnxietyArthritisAsthma & AllergiesBreast CancerCancerCardiovascular HealthCOVID-19Dermatology & SkincareDiabetesEnvironment & SustainabilityExercise & FitnessEye HealthHeadache & MigraineHealth EquityHIV & AIDSHuman BiologyInflammatory Bowel DiseaseLeukemiaLGBTQIA+Men's HealthMental HealthMultiple Sclerosis (MS)NutritionParkinson's DiseasePsoriasisSexual HealthWomen's HealthDiscoverNewsLatest NewsOriginal SeriesMedical MythsHonest NutritionThrough My EyesNew Normal HealthPodcastsHow to understand chronic painWhat is behind vaccine hesitancy?The amazing story of hepatitis C, from discovery to cureNew directions in dementia researchCan psychedelics rewire a depressed, anxious brain?Why climate change matters for human healthToolsGeneral HealthDrugs A-ZHealth HubsHealth ToolsBMI Calculators and ChartsBlood Pressure Chart: Ranges and GuideBreast Cancer: Self-Examination GuideSleep CalculatorHealth ProductsAffordable Therapy OptionsBlood Pressure MonitorsDiabetic SuppliesFitness TrackersHome GymsGreen Cleaning ProductsHow to Shop for CBDQuizzesRA Myths vs FactsType 2 Diabetes: Managing Blood SugarAnkylosing Spondylitis Pain: Fact or FictionConnectAbout Medical News TodayWho We AreOur Editorial ProcessContent IntegrityConscious LanguageNewslettersSign UpFollow UsMedical News TodayHealth ConditionsDiscoverToolsConnectSubscribe What to know about sensorineural hearing lossMedically reviewed by Nicole Leigh Aaronson, MD, MBA, CPE, FACS, FAAP — By Karen Veazey on September 13, 2022Sensorineural hearing loss (SNHL) describes hearing loss that occurs as a result of damage to the structures of the inner ear or auditory nerve. A person can acquire SNHL over time, develop it suddenly, or it can be present at birth. According to a 2019 article, SNHL is the cause of over 90% of hearing loss cases in adults. The ear has three parts — the outer, middle, and inner ear. SNHL occurs when there is damage to the inner ear or issues with the auditory nerve that conducts messages between the inner ear and brain. This article discusses SNHL, its symptoms, causes, and treatment options. What is it Share on PinterestWestend61/Getty ImagesSNHL is a type of hearing loss that occurs as a result of inner ear damage. It can develop when tiny hairs — stereocilia — become damaged and die off. These hairs are in a part of the inner ear called the cochlea. People may not notice any hearing loss until more than 30–50% of these hairs have become damaged or destroyed. It can also happen if:the auditory nerve becomes damagedthere is trauma to the structures of the inner earthere is atypical development of the cochlea or inner ear structures during fetal development SNHL can be acquired, sudden, or congenital:Acquired: There are many causes of acquired SNHL. For example, a person can acquire SNHL over time due to exposure to loud noises. Exposure to sounds above 85 decibels (dB) can start to damage a person’s hearing over time. This is the equivalent to city traffic from inside the car, gas-powered lawnmowers, and leaf blowers.Sudden: Sudden SNHL has a variety of causes, such as infection, head trauma, or other medical conditions. Congenital: For approximately 1–3 people in every 1,000, the cause is genetic, and they are born with a predisposition toward hearing loss. Research to determine if cochlear damage is repairable in children who develop SNHL early in life has so far shown inconclusive results. Degrees of hearing loss Depending on how much damage has occurred, SNHL can range from mild hearing loss to profound hearing loss. According to the American Speech-Language-Hearing Association (ASHA), an audiologist bases this on how loud a sound needs to be for a person to hear it. The following table outlines the degrees of hearing loss:Hearing loss degreeHearing loss in decibels (dB HL)slight16–25 mild26–40 moderate41–55 moderately severe56–70 severe71–90 profoundover 91 Types of sensorineural hearing loss Depending on the cause, a person may experience sensorineural hearing loss in one or both ears:Bilateral hearing loss: This occurs when there is hearing loss in both ears. It can be hereditary or develop as a result of medication and noise exposure. Unilateral hearing loss: This is partial or total hearing loss in one ear. It can be hereditary or develop due to head trauma or viral or bacterial infections.Asymmetrical hearing loss: This refers to hearing loss that affects both ears. However, one side is more affected than the other. This occurs when there is more than a difference of 15 dB hearing range between the ears. Asymmetrical hearing loss can develop due to head injury, medications, aging, noise, or genetic causes. Vs conductive hearing loss According to the National Institute on Aging, conductive hearing loss develops when the sound waves are unable to reach the inner ear. SNHL develops when there is damage to the inner ear. Conductive hearing loss might develop as a result of:earwaxthe presence of a tumoreardrum perforationfluid in the earforeign object in the ear An individual can have both conductive and sensorineural hearing loss, called mixed hearing loss. Symptoms The symptoms of SNHL can be gradual or sudden. Some symptoms include:muffled soundsdifficulty understanding speechgradual or sudden hearing lossa full sensation in the earringing in the eardizziness If a person notices symptoms of SNHL, they should make an appointment with a doctor or audiologist for a hearing evaluation. Causes There are many different causes of SNHL. Congenital A 2022 article notes that 50% of cases occur due to genetic factors. The other 50% develops due to environmental factors. Some environmental factors can include:infection, such as:congenital cytomegalovirusrubellatoxoplasmosissyphilisherpesmedicationspremature birthlow birth weight Acquired Acquired SNHL can develop as a result of:presbycusis, which is the gradual hearing loss that develops as a person agesexposure to loud noiseshead injuryMénière’s diseaseinfections, such as meningitisdiabetesautoimmune inner ear diseasevestibular schwannoma, which is a benign tumor that presses against the auditory nervemedications, such as loop diuretics and some types of chemotherapybarotrauma, which refers to damage that occurs as a result of abrupt changes in air or water pressure Sudden Sudden SNHL has a variety of causes. However, only 10% of people have an identifiable cause. Causes of sudden SNHL include:head traumainfectionsautoimmune conditionsconditions affecting blood circulationneurological conditions, such as multiple sclerosisMénière’s disease People should consider sudden SNHL to be a medical emergency. People should contact a doctor as soon as possible if they experience sudden hearing loss. Diagnosis A doctor or audiologist may perform the following tests to diagnose SNHL:Rinne test: An audiologist strikes a tuning fork and places it against the mastoid bone behind the ear. They will do this until a person is no longer able to hear the sound. They will then move the tuning fork in front of the ear canal until a person can no longer hear the sound. If the sound was better when the audiologist held the tuning fork in front of the ear canal, they may have SNHL.Weber test: An audiologist strikes a tuning fork and places it against a person’s forehead. If the sound is louder in the affected ear, the hearing loss is conductive. If it is louder in the unaffected ear, a person has SNHL.Pure tone audiogram: This measures the ears’ ability to hear different tones and sounds conducted through the air and the bones of the skull. A healthcare professional will perform the Rinne and Weber tests together. Other tests include:tympanometry to assess the function of the middle earotoacoustic emissions test, which checks the inner ear’s response to soundelectrophysiological tests to measure the activity of the nervous systemspeech audiometry to test the impact of the hearing loss on a person’s ability to communicateCT scans and MRI scans A doctor may also perform acoustic reflexes. This tests the reflex contraction of the muscles in the middle ear. They may also perform other laboratory tests depending on the potential cause of SNHL. Treatment The doctor will devise a treatment plan based on the underlying cause, the level of hearing loss, and the potential for restoring any hearing. Hearing aids are the main form of treatment if the cause is chronic, such as presbycusis. Depending on the cause, other treatment options may include:corticosteroids to treat sudden hearing losscontinued observation, including hearing testsmedication with corticosteroids to reduce swelling following loud noisessurgery to fit a type of hearing device called a cochlear implant If the cause is Ménière’s disease, a doctor may suggest diuretics and a low sodium diet. If this does not work, they may administer transtympanic steroid injections or perform a procedure called endolymphatic sac decompression. Outlook Acquired SNHL typically progresses slowly, and a person is able to manage the condition with hearing aids and regular appointments with an audiologist. If a person is eligible, cochlear implants can help to improve hearing loss, even if it is profound. In 32–65% of cases, sudden SNHL can resolve without medical treatment. For those with sudden SNHL, the outlook depends on:when it developeda person’s agewhether a person has vertigothe degree of hearing loss The outlook tends to be poorer in older adults and those with vertigo or severe hearing loss. For a better outlook, it is important for people to seek treatment quickly. When to contact a doctor People should contact a doctor if they have any symptoms of SNHL. However, it is particularly important to seek medical help if a person experiences sudden SNHL. This is because the cause may be a medical emergency, such as head trauma or infection. Summary SNHL is a common cause of hearing loss, particularly as people age. It can cause sounds to be quieter, muffled, and distorted, and voices can be difficult to distinguish in loud environments. There are several causes of SNHL, including age, medications, disease, infection, tumor, head trauma, and loud noise. All of these can cause the tiny hairs in the cochlea to die off, or damage the auditory nerve, resulting in hearing loss. SNHL is usually irreversible, and treatment involves assistive listening devices. Last medically reviewed on September 13, 2022Hearing / DeafnessSeniors / Aging 14 sourcescollapsedMedical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.Allen, S. B., et al. (2022). Syndromic sensorineural hearing loss.https://www.ncbi.nlm.nih.gov/books/NBK526088/Asymmetric hearing loss. (n.d.).https://www.hear-it.org/asymmetric-hearing-lossBilateral hearing loss. (n.d.).https://www.hear-it.org/bilateral-hearing-lossChen, M. M., et al. (2017). Diagnosis and management of congenital sensorineural hearing loss.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5222593/Degree of hearing loss. (n.d.).https://www.asha.org/public/hearing/degree-of-hearing-loss/Hearing loss: A common problem for older adults. (2018).https://www.nia.nih.gov/health/hearing-loss-common-problem-older-adultsHow does loud noise cause hearing loss? (2020).https://www.cdc.gov/nceh/hearing_loss/how_does_loud_noise_cause_hearing_loss.htmlRalli, M., et. al., (2017). Acquired sensorineural hearing loss in children: current research and therapeutic perspectives.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5782428/Sensorineural hearing loss. (n.d.).https://www.asha.org/public/hearing/sensorineural-hearing-loss/Sudden deafness. (2018).https://www.nidcd.nih.gov/health/sudden-deafnessTanna, R. J., et al. (2022). Sensorineural hearing loss.https://www.ncbi.nlm.nih.gov/books/NBK565860/Tyagi, B., et. al. (2019). Platelet rich plasma (PRP): A revolutionary treatment of sensorineural hearing loss.https://www.researchgate.net/publication/337731185_Platelet_Rich_Plasma_PRP_A_Revolutionary_Treatment_of_Sensorineural_Hearing_LossUnilateral hearing loss and single sided deafness. (n.d.).https://www.hear-it.org/single-sided-deafnessWhat noises cause hearing loss? (2019).https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.htmlFEEDBACK:Medically reviewed by Nicole Leigh Aaronson, MD, MBA, CPE, FACS, FAAP — By Karen Veazey on September 13, 2022 Latest newsWhat sets 'SuperAgers' apart? Their unusually large neuronsOmega-3 may provide a brain boost for people in midlifeSeasonal affective disorder (SAD): How to beat it this fall and winterCDC: Monkeypox in the US 'unlikely to be eliminated in the near future'Why are more women prone to Alzheimer's? 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