Hearing Loss

Whether or not you have hearing loss personally, chances are you know somebody that does.

Doctor Examining Child's Ears

Today, more than 500 million people experience some degree of hearing loss, making it the most common sensory disorder worldwide. Every day, the potential threats to our hearing increase. While many people blame a variety of sources for this epidemic—industrialization, earbuds, or the aging process—the need for a global hearing health awareness campaign is critical. In loud environments, ear protection is the only dependable way to prevent hearing loss and can keep existing concerns from worsening over time. While this website seeks to provide you with the most up-to-date and relevant information on hearing loss and treatment options, a hearing care professional is the best source of options for protecting or improving your hearing.

Types of hearing loss

Hearing loss is characterized by the reduced function of the ear and/or auditory system. Generally, hearing loss limits the ability to perceive one or more of these three qualities of sound:

  • Frequency resolution, or the ability to distinguish between two pitches
  • Temporal resolution, or the ability to determine the timing of sound events
  • Volume, or the spectrum of sound that can be heard from quietest to loudest

If you are experiencing some sort of hearing loss, a hearing care professional will be able to determine the type and severity of your condition. The four types of hearing loss include:

  • Sensorineural (affects the inner ear)
  • Conductive (affects the middle ear)
  • Mixed (affects both)
  • Auditory processing disorders

The most common type of hearing loss is sensorineural. When compromised hearing presents with no detectable damage to the outer or middle ear, a hearing care professional will examine the inner ear for signs of sensorineural hearing loss. With this condition, sound passes into the inner ear without interference but is interrupted before it reaches the brain. This can be caused by an impairment of the auditory nerve, hair cells, and/or cochlea. Those with sensorineural hearing loss regularly experience difficulty understanding speech as well as decreased sensitivity to volume and higher frequencies. Hearing aids can help restore hearing ability in the higher ranges, allowing users to more accurately perceive sounds like birds singing and high-pitched voices (e.g., children’s).

Contracting sensorineural hearing loss later in life signifies that damage has occurred in ear. There are a number of potential causes for this, such as:

  • Diseases
  • Aging
  • Brain injury
  • Ototoxic (ear damaging) medications
  • Prolonged exposure to noise
  • Ear infections

Congenital hearing loss of the inner ear can be hereditary, or it can result from complications during pregnancy. Children born prematurely with viral infections or restricted oxygen flow are all susceptible to sensorineural hearing loss.

Conductive hearing loss occurs when sound encounters difficulty passing from the middle ear into the inner ear. Various potential causes of conductive hearing loss commonly include birth defects, puncturing of the eardrum or ossicles, ear infections, injuries to the ear, and other head traumas. In many cases, the inner ear does not require treatment, as it is only the damaged outer/middle part of the ear that prevents sound from traveling. Surgery and certain medications have been proven to correct temporary conductive hearing loss, while those with permanent damage to the middle ear can benefit greatly from a hearing aid.

Auditory processing disorders

There is some debate as to whether or not an auditory processing disorder (APD) can really be considered a type of hearing loss. Unlike the other forms that directly affect the ear and its various parts, those with an APD receive and process sound normally. In this situation, it is the brain that is unable to properly interpret the signals sent by your ear as something intelligible, particularly in regards to language. Parts of speech are often distorted and indistinguishable, complicating the ability to register emotion and other conversational cues. In this way, APD can prevent someone from comprehensively listening to their surroundings, which could constitute a loss of hearing. If you find speech difficult to isolate because of an APD, hearing aids with microphones that enhance sound coming from the direction in which you’re facing have been shown to drastically increase variations in tonality, and can help wearers distinguish between different sounds and voices.

Because the condition is neurological and often not tested for during a physical exam, APDs in children can be mistaken for a different kind of learning disability. We encourage parents to take a look at the following list of symptoms and consider whether your child may have an undiagnosed APD:

  • Difficulty paying attention and remembering auditory information
  • Difficulty completing tasks that require multi-step directions
  • Difficulty forming sentences using proper grammar, syntax, and vocabulary
  • Behavior problems
  • Poor listening skills
  • Delayed academic performance, particularly affecting reading, spelling, and vocabulary

Degrees of hearing loss in adults

In addition to your ability to understand speech, hearing loss severity is determined by the minimum decibel level required for hearing to occur. From mild to profound, the varying degrees of hearing loss can usually be treated with hearing aids. To better understand how hearing loss is measured in adults, consult the following table. If your child has hearing loss, visit our page on hearing loss in children for more information on pediatric diagnostic and treatment options.


A number of potential causes

Many people believe that by avoiding loud sounds that they can retain perfect hearing. Unfortunately, hearing loss can be caused by more than noise exposure and aging. Illness and infections can also play a part in damaging your hearing. A University of Wisconsin Medical School 2001 study revealed that hearing loss occurred in nearly 80 percent of those who may have suffered  a heart attack. They further determined that individuals who exercised at least once a week experienced a 32 percent reduction in the risk of developing hearing loss compared to those who did not work out.

Other health issues associated with either temporary or permanent hearing loss include the following:

  • Poor blood flow to the ear
  • High blood pressure
  • Sickle cell disease
  • Diabetes
  • Vitamin B-12 and folate deficiencies
  • Chemotherapy
  • Use of painkillers and some antibiotics
  • Genetics
  • Smoking
  • Head injuries

Screenings for diabetes and other conditions typically do not include hearing tests. If you have one of these conditions, ask your primary care physician for a referral to a hearing care professional who can conduct a hearing screening to see if you suffer from any kind of hearing loss.

There are options for improvement

While 500 million cases of hearing damage are shocking enough, the amount of unreported or undiagnosed hearing loss means that number should be much higher. In almost every case, early treatment could be life-changing even for those who believe their ears are in perfect health. With your help, we can end the stigma against hearing loss. Please consult our listing of hearing care professionals in your area to set up an appointment. You might be surprised by the amount of non-intrusive, discreet options available for your lifestyle and budget.

[1] World Health Organization. 

[2] Torre P 3rd, Cruickshanks KJ, Klein BE, Klein R, Nondahl DM. (2005). The association between cardiovascular disease and cochlear function in older adults. http://jslhr.asha.org/cgi/content/abstract/48/2/473