Hearing loss refers to reduced hearing from a disorder in one or more parts of the ear. It can affect people of all ages.
Sound waves usually move through the external ear canal and vibrate the eardrum. The vibrations then pass through the middle ear bones to the cochlea (the part of the inner ear for hearing). The cochlear sensory cells receive the vibrations and send signals to the auditory nerves (hearing nerves) and to the brain, which recognises these signals as sounds.
Disruption in this natural process can lead to hearing problems and hearing loss.
Types of hearing loss
Conductive hearing loss, which occurs when there are disruptions in the passage of sound waves from the outside environment to the cochlea. For example, this type of hearing loss can result from ear wax in the outer ear, infections of the outer or middle ear, and eardrum perforations.
Sensorineural hearing loss, which occurs when the inner ear structures or the nerve pathways to the brain are damaged. This is commonly seen in presbycusis where age-related gradual hearing loss occurs in both ears.
Mixed hearing loss, which is where both conductive and sensorineural hearing losses occur in the same ear.
What are the symptoms of hearing loss?
Hearing loss can occur suddenly or gradually, and it can affect one or both ears. Its symptoms include:
Difficulty understanding what other people are saying, especially with background noises
Speaking louder than normal
Often asking for conversations to be repeated
Withdrawal from conversations
Associated ear symptoms, such as earache and ear discharge due to ear infections
Tinnitus (ringing in the ears)
Vertigo (spinning sensations)
You should contact your doctor if you experience:
Hearing loss that interferes with your daily activities
Deteriorating hearing loss
Sudden hearing loss
Hearing loss together with other ear symptoms such as pain, discharge, blockage and vertigo
What are the causes of hearing loss?
Ear wax. This can completely obstruct the outer ear, resulting in conductive hearing loss.
Infections. Bacteria can cause infections in the outer, middle and inner ear. The outer ear is also commonly affected by fungus and the inner ear by viruses. As the middle ear is connected via the Eustachian tube to the nose, nasal infections can also affect the middle ear.
Loud noises. Over prolonged periods of time, loud noises can gradually damage inner ear cells. This can happen during work or even during leisure activities. Accidental exposure to explosive blast sounds can also damage the ear almost immediately.
Ageing. Inner ear cells and nerve structures degenerate as one ages.
Medications. These include certain antibiotics, diuretics and cancer treatment drugs.
Trauma. The eardrum can be damaged accidentally, such as during cleaning of the ear with cotton swabs. Severe blunt injury to the head may also indirectly damage ear structures.
Hereditary. Genetic causes may result in hearing loss among family members.
What are the complications and related diseases of hearing loss?
In children, hearing loss can affect speech and language development as well as school performance. In adults, it can affect one’s performance at work. With constant communication difficulties, it can have a considerable negative effect on quality of life.
Other complications and related diseases of hearing loss include:
Mental health problems. People who have hearing loss, especially older adults, may record feelings of depression and isolation because of difficulty in making a conversation.
Cognitive decline. Hearing loss is also linked with cognitive impairment and decline. Treating hearing loss can create a positive impact on cognitive performance, especially in memory.
Gut problems due to stress. Being deprived of hearing can be really stressful. Digestive problems like diarrhoea, indigestion and constipation are common symptoms of stress and anxiety.
How do you prevent hearing loss?
To help prevent noise-induced hearing loss, protect your ears by limiting the duration and intensity of your noise exposure, such as using earplugs or earmuffs in the workplace. Consider having your hearing tested if you work in a loud environment.
You can also avoid risky recreational activities such as snowmobiling, hunting, using power tools, or listening to rock concerts. Turning down the music volume or taking breaks from the noise can also prevent ear damage.