All About Hearing Loss: Types, Causes, Signs and Treatment

Hearing loss is a condition affecting millions worldwide. According to the Ministry of Health Malaysia, at least 21.57% of the population suffers from hearing loss¹.

Broadly categorised as either acquired or congenital, this condition can be developed over time or present from birth. While congenital hearing loss is permanent, acquired hearing loss can be permanent or temporary.

Temporary hearing loss can be acquired from situations like earwax blockage or middle ear infections. It may resolve on its own or require treatment to address the underlying cause. On the other hand, permanent hearing loss is irreversible, with no effective medical treatments to restore hearing.

Understanding the distinctions between these types of hearing loss is crucial in navigating the impacts and seeking appropriate interventions. Keep reading to learn more.

• What Is Hearing Loss?
• What Are the Types of Hearing Loss?
• What Are the Causes of Hearing Loss?
• What Are the Common Signs of Hearing Loss?
• Degree of Hearing Loss
• How to Diagnose Hearing Loss
• What Are the Treatment and Management Options for Hearing Loss?
• FAQs About Hearing Loss

Hearing loss is the reduced ability to hear sounds clearly or at normal levels. It can affect one (unilateral hearing loss) or both ears (bilateral hearing loss), and may develop gradually or occur suddenly. Hearing loss can make it difficult to follow conversations, especially in noisy environments, and may lead to misunderstandings or listening fatigue.

There are three primary types of hearing loss, each associated with damage to different parts of the ear.

The most common type of hearing loss is sensorineural hearing loss, which can be present at birth (congenital) or acquired later in life. Characterised by damage to the inner ear (cochlea) or its associated nerves, this form of hearing loss usually leads to permanent impairment. Individuals with sensorineural hearing loss often perceive voices as unclear or distorted, and sounds may seem softer.

Conductive hearing loss occurs when damage or obstruction in the outer or middle ear affects the transmission of sound waves to the inner ear. This disruption in the sound pathway causes sounds to be perceived as softer than normal. Unlike sensorineural hearing loss, conductive hearing loss can be treated with surgery or medication to address the underlying issue in the outer or middle ear.

Damage to the middle and inner ear results in mixed hearing loss, a combination of sensorineural and conductive hearing loss. This condition can stem from causes of both types of hearing loss. Treatment for this condition effectively depends on identifying and addressing the specific contributing factors.

The causes of hearing loss depend on the type of hearing loss you are diagnosed with.

Symptoms of hearing loss can manifest at different paces and might be tricky to spot. The following signs are based on guidelines from the Ministry of Health Malaysia.

The degree of hearing loss is based on how loud sounds need to be for the individual to hear them. It’s measured in decibels (dB) and can be grouped into four levels: mild, moderate, severe and profound.

• Mild (21 – 40 dB)

For those with mild hearing loss, following conversations in noisy settings can be difficult. They may struggle to understand speech clearly, commonly missing softer sounds and speech nuances. 

• Moderate (41 – 70 dB)

Individuals experiencing moderate hearing loss might compensate by adjusting their environment, such as raising the television volume. Communication may become challenging at this stage and feelings of isolation may develop. Without sound amplification devices like hearing aids, quality of life may deteriorate.

• Severe (71 – 90 dB)

At this stage, environmental sounds can be challenging to perceive even with a hearing aid. Effective communication often requires additional strategies, such as lip-reading, sitting close to speakers, and asking them to speak slowly and clearly. These tactics help improve speech understanding and ensure meaningful interactions despite the hearing loss.

• Profound (>90 dB)

Even with a hearing aid, individuals with profound hearing loss find listening challenging. They often rely on communication strategies similar to those used by individuals with severe hearing loss.

An Ear, Nose and Throat (ENT) doctor or audiologist will carry out the following tests to diagnose hearing loss.

The doctor will typically conduct a physical examination that includes inspecting the ear canal, tympanic membrane (eardrum), nose, and nasopharynx. Additionally, a neurologic exam may be carried out to assess nerve function related to auditory processing and transmission. 

Hearing tests, or audiometry tests, will be conducted to identify the type and severity of the hearing loss. Different tests may be recommended for adults as well as babies and children, depending on their symptoms and the physical examination.

In cases of suspected conductive hearing loss, a tympanometry test may be recommended to evaluate middle ear function and assess the integrity of the eardrum. These tests are crucial in diagnosing hearing issues accurately and guiding appropriate treatment strategies.

In some cases, radiological imaging techniques such as Computed Tomography (CT), Magnetic Resonance Imaging (MRI), or other scans may be recommended to detect acoustic neuroma, a benign tumour that can potentially lead to hearing loss.

Effective treatment or management of hearing loss depends significantly on the type and severity of the condition. From simple interventions such as earwax removal to devices such as hearing aids, audiologists tailor treatment plans to address individual hearing needs.

To address conductive hearing loss caused by earwax buildup, earwax removal via ear irrigation or microsuction is necessary. This clears up the obstruction within the ear canal and restores hearing.

Hearing aids are devices designed to improve hearing for individuals with sensorineural or conductive hearing loss by detecting and amplifying sounds in the environment. They’re effective across various degrees of hearing impairment, enhancing clarity and enabling better auditory perception.

Cochlear implants are advanced devices surgically placed in the inner ear to address sensorineural hearing loss. These devices bypass damaged auditory components to stimulate the auditory nerve directly. They can be worn by individuals of all ages and are primarily recommended for moderate to severe hearing loss.

However, due to its invasive nature, this procedure is considered only when individuals demonstrate limited benefit from hearing aids and have poor speech intelligibility scores.

Medications like topical antibiotics are commonly prescribed for ear infections. If a medication is found to cause hearing loss, it may be discontinued or replaced with a safer alternative.

Surgery may be used to address conditions such as recurring ear infections, otosclerosis or perforated eardrums. Each surgical procedure focuses on addressing the root cause of the condition being treated.

¹Referenced from the Ministry of Health Malaysia
²Referenced from the World Health Organisation (WHO)