Causes of Hearing Loss

Hearing Loss at Birth

Hearing loss and deafness may be caused by hereditary and non-hereditary factors.

In Wisconsin, we are lucky to have universal newborn hearing screening to identify hearing loss at birth.

Factors that may cause hearing loss at birth include:

  • High-risk infants, infants born prematurely

  • Maternal rubella, syphilis or other infections during pregnancy

  • Maternal use of drugs during pregnancy including anti-malarial drugs, diuretics, aminoglycosides, cytotoxic drugs and others

  • Severe jaundice in the neonatal period

Genetic (inherited) factors:

Usher’s Syndrome, Alport’s Syndrome, Paget’s Disease, Waardenburg’s Syndrome, Pendred’s Syndrome.

A detailed overview of hereditary hearing loss and deafness is provided in this article:

  • Shearer AE, Hildebrand MS, Smith RJH. Hereditary Hearing Loss and Deafness Overview. 1999 Feb 14 [Updated 2017 Jul 27]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1434/

Genetic hearing loss can show up later in life, such as with the DFNA10 gene.

  • O’Neill, M. E., Marietta, J., Nishimura, D., Wayne, S., Van Camp, G., Van Laer, L., … & Smith, R. J. (1996). A gene for autosomal dominant late-onset progressive non-syndromic hearing loss, DFNA10, maps to chromosome 6. Human molecular genetics, 5(6), 853-856.

Drug related

Drugs such sildenafil (Viagra), certain chemotherapy drugs, and loop diuretics can cause hearing loss and tinnitus (ringing in the ears). Use of drugs used to treat infections, malaria, drug resistant tuberculosis, and cancer may cause hearing loss. Aspirin and quinine cause temporary hearing loss and tinnitus, particularly when given at high doses. Quinine products can also temporarily reduce balance ability.

  • https://www.dizziness-and-balance.com/disorders/bilat/ototoxins.html

Aminoglycoside antibiotics such as kanamycin, tobramycin, streptomycin, neomycin, can cause cochlear (hearing) damage, vestibular (balance system), and damage to the kidneys. Gentamicin and tobramycin primarily affect the balance system, while neomycin, kanamycin, and amikacin mainly affect hearing.

These antibiotics primarily damage the mitochondria in the hair cells of the inner ear. Mitochondria evolved from symbiotic bacteria-like cells billions of years ago and are the main source of energy in most cells. Because mitochondria are important in all the cells of our body, drugs that affect mitochondria can affect a variety of body functions. For example, in 2008 the FDA issued an alert about a class of antibiotics called fluoroquinolones. Side effects included tendon rupture and irreversible nerve damage. In 2016, the agency accepted the existence of a potentially permanent syndrome that it calls fluoroquinolone-associated disability (FQAD) and recommended that the drugs be reserved for serious infections.

  • Marchant, Jo When antibiotics turn toxic. Nature. 2018 Mar 22;555(7697):431-433. doi: 10.1038/d41586-018-03267-5.

Environmental factors

Certain types of inherited hearing loss may not be apparent unless they are triggered by environmental factors. For individuals who carry specific variants in the mitochondrial gene, MT-RNR1, a single dose of gentamicin antibiotic can result in rapid profound permanent hearing loss even though the drug level is within range that is tolerated by many people. Commercial tests are presently available to detect this deletion (the A1555 deletion). The prevalence of this mutation is around 1-2% of the normal population.

  • Dean L. Gentamicin Therapy and MT-RNR1 Genotype. 2015 Apr 29 [Updated 2018 Aug 1]. In: Pratt VM, McLeod HL, Rubinstein WS, et al., editors. Medical Genetics Summaries [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 2012-.

Medical and health factors

Vision, Cardiac, and Kidney diseases may be associated with hearing loss

  • Diabetes, Thyroid problems – any process that causes a disruption in the metabolic or cardiac function of the human body.

  • Viral and Bacterial infections

  • Meningitis, measles, cytomegalovirus, and mumps and other infectious diseases

  • Chronic middle ear disease

  • Use of drugs used to treat infections, malaria, drug resistant tuberculosis, and cancer

  • Closed head injury

Noise Exposure

Hearing loss due to noise exposure can be temporary or permanent. If you have ever gone to a loud concert and come out with your ears feeling stuffed up and perhaps ringing those are signs of ear fatigue or temporary threshold shift (TTS). Over time and with repeated exposure, this decrease in hearing can become permanent (PTS). The dilemma is that we have no way to know when temporary loss can become permanent since individuals have different susceptibility based on family history, personal health history, drug use and previous noise exposure. Even if the noise is “good noise,” such as music, your ears do not know the difference. Exposure to a very loud sudden blast or prolonged exposure to loud levels of sound can cause permanent hearing loss.

Engaging in the following activities without proper hearing protection can cause permanent hearing loss:

  • Recreational Noise Exposure – Motorcycles, Car Racing, Hunting, Sport Shooting, Power Tools, Shop Equipment, Lawn Mowers, Chain Saws, and many other loud hobbies.

  • Flying – If you are planning a trip on an airplane make sure to take earplugs and/or noise cancelling headphones. At take-off and landing, noise inside the plane can be as high at 105 dBA. Sound levels when you are at cruising altitude can extend for several hours at 85 dBA which is hazardous to your hearing. If you have a choice, select a seat that is forward of the wings and in the aisle. Take-off and landing can also be hard on your middle ears, especially if you have trouble equalizing pressure. Never fly with a cold or sinus problems as it can result in permanent hearing changes.

  • Occupational Noise Exposure – OSHA regulates noise exposure in the workplace. If you feel that your job is noisy and you need hearing protection, discuss this with your supervisor or plant health officer.

  • Military Noise Exposure – Hearing loss is the number one compensable service-connected disability. Tinnitus is among the top conditions. The military has an active hearing conservation program and is researching hearing protection devices and the use of antioxidants to protect the hearing of its members.