Many individuals often overlook the limitations of their hearing abilities, primarily because they are unaware of the sound intensity thresholds their ears can safely tolerate. Excessive exposure to noise can potentially damage delicate inner ear structures. This can include loud noises in a work environment or during recreational activities like attending concerts or listening to high-volume music.
Sometimes, this damage develops into a condition known as noise-induced hearing loss (NIHL). In Singapore, noise-induced hearing loss is a major contributor to occupational diseases, thus making it a significant ENT concern.
Understanding Noise-Induced Hearing Loss
Noise-induced hearing loss (NIHL) is a form of sensorineural hearing loss that develops from exposure to repeated or intermittent loud noises exceeding 85 decibels. It typically occurs when the cochlea—the delicate hair cells in the inner ear responsible for transmitting sound signals to the brain—become damaged or die off due to chronic noise exposure. Once these hairs and inner ear structures are damaged, they can no longer regenerate or be restored.
Two Types of Noise-Induced Hearing Loss
- Acute NIHL: This type of NIHL happens when the inner ear is damaged suddenly following a single traumatic event like an explosion. It may lead to immediate and permanent hearing loss, often accompanied by pain or a feeling of fullness in the ears.
- Chronic NIHL: This develops gradually over time due to continuous exposure to moderately loud noise from occupational hazards or during extended periods of recreational activities. Symptoms may not manifest immediately; it may take weeks, months, or even years for individuals to notice changes.
What Are the Causes of Noise-Induced Hearing Loss?
Noise-induced hearing loss is caused by several common loud noise sources, such as:
- Occupational Noise: Machinery and equipment in many occupations, such as construction and factory work, generate high noise levels. This prolonged exposure to high decibel levels can increase the risk of NIHL.
- Recreational Activities: Exposure to loud sounds from leisure activities like attending concerts, visiting clubs, or listening to music at high volumes (especially through personal audio devices) can cause gradual hearing damage.
- Urban Noise Pollution: It is possible to develop NIHL by living in a noisy urban environment or being exposed to loud traffic, sirens, or public transportation such as the MRT.
Symptoms of Noise-Induced Hearing Loss
The symptoms of NIHL may appear immediately after exposure to very loud noise, or they may develop gradually over time, often going unnoticed until hearing loss becomes more severe.
Some common signs and symptoms of NIHL include:
- Difficulty hearing high-pitched or soft and faint sounds
- A feeling of fullness or pressure in the ear
- Muffled or distorted speech, particularly in noisy environments
- Tinnitus (ringing or buzzing sounds in the ears)
- Gradual loss of hearing sensitivity
How Is Noise-Induced Hearing Loss Diagnosed?
Diagnosing noise-induced hearing loss often starts with an assessment of the patient’s history, including noise exposure patterns, symptom timeline, and medical history. Following this evaluation, an ENT specialist will look for any structural problems or wax buildup in the ear that can exacerbate hearing loss.
Moreover, the ENT specialist may conduct specialised hearing tests, which typically include:
- Speech Discrimination Test: This test evaluates the patient’s ability to hear and understand speech at different volumes and background noise levels, helping assess the impact of hearing loss on communication.
- Pure Tone Audiometry: This test measures hearing sensitivity across different frequencies to determine the degree and type of hearing loss.
- Tympanometry: This test assesses the movement of the eardrum in response to changes in air pressure, helping detect middle ear issues such as fluid buildup or eustachian tube dysfunction.
- Otoacoustic Emission Test: This test evaluates sound emissions produced by the cochlea in response to auditory stimuli, providing insights into cochlear function and outer hair cell activity.
Treatment Options for Noise-Induced Hearing Loss
While noise-induced hearing loss is generally irreversible, there are various treatment options available that can help manage symptoms and improve auditory comprehension. Treatment options for NIHL include:
- Medication Management: An ENT specialist may prescribe certain medications, such as corticosteroids, to alleviate discomfort, particularly in acute cases.
- Hearing Aids: Managing NIHL primarily involves the use of hearing aids, which amplify the surrounding sound waves for improved acoustics, particularly for those with mild to moderate hearing loss. There are many types of hearing aids, including ones that are worn behind the ear or within the ear.
- Cochlear Implants: For individuals with significant high-frequency hearing loss, the ENT specialist may recommend a cochlear implant. This surgically implanted device bypasses the damaged portions of the ear and transmits sound signals directly to the auditory nerve to restore or improve hearing.
Noise-induced hearing loss cannot be reversed, but it is preventable with the right strategies, such as wearing hearing protection and limiting noise exposure. In addition, routine hearing check-ups are very helpful to monitor your auditory health and detect potential issues at an early stage.
If you are experiencing hearing problems and suspect that you may have NIHL, then call our clinic at 6738 1616 . Get a comprehensive hearing evaluation with our ENT specialist today.
