The Link Between Trauma and Hearing Loss

Happy couple next to the lake during winter trauma and hearing loss

Trauma can be described as a deeply distressing or disturbing experience or a physical injury. Like with the rest of the human body, trauma can cause impairment to a person’s hearing abilities. There are different variations of trauma that can cause different types of hearing loss.

In addition to the 3 main types of hearing loss, the function of hearing can also be impaired when the centre of the brain that is responsible for processing the auditory signals is affected by trauma. Furthermore, the vestibular organs responsible for balance and form part of the auditory system, also face the risk of impairment from trauma.

There are different types of trauma that can affect one or more of the different areas of the auditory system. As a result, based on the extent of the trauma and area/s affected, this will pose the person at risk to one or more of the types of hearing impairments mentioned above. We now look at the different types of trauma and the effect that it has on each part of the auditory system:

Outer ear

The external ear (pinna or auricle) can be damaged by trauma or inflammation. This can occur from direct injury to the outer ear or head. It can also involve the insertion of foreign bodies in the ear canal (matchsticks, hairpins) that can cause damage to the skin in the ear canal or rupture the eardrum.

Symptoms to look out for include noticeable hearing loss which will only arise if the entrance to the ear canal is obstructed or closed up preventing sound entry. A rupture to the eardrum or damage to the skin in the ear canal will be accompanied by pain and possibly bleeding.

Middle ear

Barotrauma

Any abnormal pressure in the middle ear cavity, due to inadequate ventilation and drainage of the middle ear cavity, can put the eardrum under such stress that it causes it to perforate. Significant atmospheric pressure changes, such as when flying or diving, can cause pain and hearing loss sometimes resulting in eardrum rupture (called barotrauma). Flying or diving with a head cold increases the likelihood of barotrauma and can result in complications, even permanent hearing loss.

Trauma to middle ear bones

The chain of three tiny bones in the middle ear (ossicles or ossicular chain) transmits sound vibrations from the outer ear to the cochlea in the inner ear. These tiny bones can suffer dislocation from head trauma such as in a road traffic accident or in contact sports such as boxing or rugby.

Inner ear

Trauma to the inner ear can cause certain noises or pitches to become extremely loud or soft. This, in turn, causes a condition called hyperacusis which is the extreme sensitivity to sounds that becomes debilitating to the persons daily functioning. 

Other types of trauma

Acoustic trauma

Acoustic trauma is caused by injury to the inner ear as a result of exposure to high-decibel noise (exceeding regulated levels of noise exposure without ear protection). This injury can occur after exposure to a single, very loud noise or from exposure to noises at significant decibels over a longer period of time.

Traumatic brain injury

A traumatic brain injury (TBI) is any kind of injury that causes structural or physiological changes to brain function. It is usually the result of an external force like a blast, a direct blow, or a fall, and can present with the occurrence or worsening of any of the following signs:

  • Loss or decreased level of consciousness
  • Memory loss
  • Feeling dazed, confused, or disoriented
  • Neurological changes including weakness, loss of balance or changes in vision

Research suggests about 1.5 per 1,000 people in the USA are admitted to the hospital each year for TBI, and hearing healthcare professionals are likely to have some of them as patients. TBI may result in hearing loss and vestibular and central auditory problems.

Due to the sudden and violent nature of TBI, it may cause concurrent damage to the auditory pathway. Damage can occur at any point within the auditory pathway, from the outer ear to the cortex, which can result in a variety of complex symptoms.

Impairment due to trauma can produce conductive and sensorineural hearing loss, central auditory processing deficits, vestibular impairments, and tinnitus. The tympanic membrane, middle ear, and cochlea are the most common sites of peripheral injury as they are often directly in the line of trauma. This, in turn, can cause displacement of the middle ear bones and vestibular apparatus. The hair cells are the most vulnerable elements of the cochlea and, when damaged, can produce sensorineural hearing loss and tinnitus.

Vestibular effects

Dizziness is thought to occur in 40-60% of individuals with traumatic brain injury. 

Central effects

Injury to the auditory cortex where auditory signals are processed in the brain can result in the person experiencing difficulty interpreting auditory input. In some cases, the person will not present with hearing loss but struggle to decode what he/she is hearing.

Post-traumatic Stress Disorder (PTSD)

PTSD is a disorder that can develop after a person witnesses or experiences a traumatic or terrifying event. Given the nature of combat and war zone environments, Service members are at heightened risk for PTSD. Tinnitus (ringing or buzzing in the ear) has been associated with PTSD. Although the person may not present with hearing loss, tinnitus can cause impairment to their daily functioning. Hearing loss can sometimes have an isolating effect and tinnitus can be stressful, while both can aggravate PTSD symptoms, such as depression, anxiety, obsession, and sleep disturbances.

What can be done? Treatment options

Trauma to the outer and middle ear

Outer ear obstructions, such as earwax and other foreign objects, can often be removed by an ENT. Middle and inner obstructions, such as scarring of the eardrum, skin, or excess fluid, are usually a bit more difficult to treat, but there are still likely to be non-invasive (surgery-free) treatment options available.

More complex scenarios such as the displacement of the middle ear bones may require surgery. The surgery and treatment will depend on the extent of damage that occurred in the middle ear.

Trauma to the inner ear is usually irreversible. It is recommended that the person undergo a comprehensive audiological assessment to determine the extent of damage and thereafter consider treatment possibilities. The use of amplification (hearing aids or cochlea implants) is the most common form of treatment and management for permanent hearing loss.

Hyperacusis

Currently, there  is no cure for hyperacusis but there are many effective strategies to manage this condition, including:

  • earplugs and earmuffs to reduce sound sensitivity
  • activities such as dining out or shopping should be scheduled for quieter off-peak times
  • nicotine and caffeine are stimulants and should be avoided
  • it is helpful to maintain good health through diet, sleep, and exercise
  • specially programmed hearing aids can be used to desensitize ears through long-term exposure to gentle sound.

Acoustic trauma

Acoustic trauma can be seen as damage to the inner ear which makes amplification the most common treatment option.

TBI

TBI is a complex injury that can affect multiple areas of the brain. Patients with TBI present a distinctive and challenging population for the hearing healthcare practitioner. In addition to hearing loss, patients can endure a period or permanent disability, amongst other disruptions to the persons functioning. The treatment and rehabilitation of auditory and vestibular injury associated with TBI will require a multidisciplinary approach between otolaryngology, audiology, speech-language pathology amongst other allied health professionals. 

Vestibular

The treatment for vestibular trauma will depend on the site of injury.  The Audiologist or ENT will then apply the appropriate vestibular rehabilitation techniques based on the assessment findings. Vestibular rehabilitation usually includes specific exercises, which may include medication and rest.

PTSD

The general treatment for PTSD is the psychological management of the cause of trauma. This would include counseling and techniques to reduce anxiety or sleep disturbances. 

One of the most apparent signs of trauma-induced hearing loss is the immediate symptoms of hearing loss and associated factors like pain, dizziness, or imbalance. It is crucial that the person undergoes a comprehensive medical examination to ensure that the injuries can be addressed and healing facilitated in a timeous manner. 

Hearing expert article writer Nausheen Dawood

Written byNausheen Dawood

Masters in Audiology

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