What is acoustic trauma?

Acoustic trauma is a specific type of hearing loss that results from exposure to sudden or ongoing loud noise. For instance, a gunshot or an explosion can be examples of sudden, loud noises. Long-term exposure to loud music or any other high-volume sound can also cause acoustic trauma. The worst part of acoustic trauma is that it can lead to permanent hearing loss. 

Acute acoustic trauma occurs due to a powerful impulse noise of more than 160 dB, often combined with a sharp increase in the barometric pressure in the explosion. For example, a shot from a pistol or a rifle near the auricle usually causes temporary hearing loss or a pronounced hearing loss. 

What are the causes of acoustic trauma?

Tragically, many people are at high risk of suffering from acoustic trauma due to their occupation. For example, soldiers are commonly exposed to gunshots or explosions and musicians to loud music. Living or working in places where high-decibel sounds continue for long periods can also increase your risk. 

Other loud sound sources are riding a motorcycle or a snowmobile, working in a woodshop, or as a landscaper regularly using lawnmowers and leafblowers. However, regardless of the trauma's source, permanent hearing loss may be a very real consequence.

Whether you end up with noise-induced hearing loss depends on several factors. One is the length of exposure to the sound, and two, how loud the sound is. In general, sounds below 70 A-weighted decibels (dBA) do not result in hearing loss. Trouble would start around 85 dBA, especially if the exposure was sustained or occurred repeatedly. The distance to the source of the sound is also a factor. Obviously, the closer you were to the loud noise, the higher the likelihood of hearing loss. 

What are the symptoms of acoustic trauma?

Depending on if your acoustic trauma is triggered by sudden or longer-term noise exposure, your symptoms can be different. 
Suppose you get exposed to a sudden, loud noise, let's say a gunshot; you may begin experiencing some signs of hearing loss relatively soon after the incident, with a gradual worsening of your symptoms over time. 

If, however, your noise exposure occurred over a longer period, hearing loss may take several months or years to become noticeable. 
Thankfully, permanent hearing loss does not always happen after exposure to loud noises. Instead, some people only experience a temporary hearing loss, with their hearing returning to normal after a few days. Unfortunately, others are not so lucky and get stuck with long-term residual symptoms. 

It is important to keep in mind that the loss of hearing ability is only one of many possible symptoms of acoustic trauma, and the way you experience it can also vary. Some of the possible symptoms are: 
  • tinnitus or the sensation of ringing or buzzing in the ear
  • hearing impairment in one or both ears
  • sounds previously heard with ease are now muffled or faint
  • finding yourself asking people to speak up
  • need to turn up the volume on hone, TV, or radio more often
When acoustic trauma leads to a loss of hearing ability, it generally results in a specific type, sensorineural hearing loss. This category is the most common type of hearing loss and happens when the inner ear or the hearing nerve becomes damaged. This loss typically ensues when some of the hair cells within the cochlea become harmed. Besides loud noise exposure, aging, injury, certain drugs, and diseases can be at the root of this condition. Although sensorineural hearing loss is rarely treatable, hearing aids can be beneficial to mitigate its symptoms. 

How is acoustic trauma diagnosed?

If you were exposed to loud noise and notice any degree of hearing loss or other symptoms, you should seek medical attention. Your doctor will likely conduct a physical exam to determine if the eardrum is damaged. 

Suffering a noise-induced injury warrants a hearing test or an audiogram. The latter is a graph that shows the threshold of audible sounds for standardized frequencies. The device used to perform this test is an audiometer. 
An audiometry exam may also be done. This test is used to determine how much hearing has been lost by measuring hearing acuity for variations in sound intensity and pitch (high-pitched and low-pitched sounds) and tonal purity. It also involves thresholds and differing frequencies.

How is acoustic trauma treated?

Your audiologist should develop a personalized treatment plan for you, considering multiple factors. Your doctor should be clear on the type of hearing loss you have and recommend treatment options that have the best chance to work for your specific case. 

Generally, doctors focus on preventing any further loss of hearing ability and restoring as much of it as possible. Typical treatments used for acoustic trauma-related hearing loss are eardrum repair, steroid treatment, and hearing aids. 

What is the prognosis?

Progressive hearing loss and tinnitus are the primary complications. Unfortunately - as mentioned above - acoustic trauma-related hearing loss is often permanent. 

To safeguard your hearing ability, be sure to prevent loud noise exposure in the future as much as possible. For example, wear ear protection - such as earplugs or earmuffs - when around loud sound sources to avoid your condition from getting worse. 
In addition, be mindful of any activities that could expose your ear to suffering further damage. Wear protective gear or avoid these activities altogether. 

Although many people love listening to deafening music in their car or at home, resist the temptation of listening to loud music for long periods.
The information contained in this article is for educational and informational purposes only. You should not use the information as a substitute for, nor should it replace, professional medical advice. If you have any questions about your health, you should always consult with a physician or other health-care professional.