Hearing Loss Otolaryngology (ENT) - Head and Neck Surgery Our ear is a complex system of mechanisms that work together seamlessly to allow us to enjoy the sounds around us. When sound waves enter the ear, they are conducted through the eardrum into the middle ear, and transmitted via small bones in the middle ear to the cochlea in the inner ear. In the cochlea, the vibrations are translated into electrical signals which are passed on to the brain along the auditory nerve, where they are being interpreted as sounds. Hearing Loss Hearing loss is a reduction in how well you can hear, and it can affect people of any age. It is particularly prevalent amongst the elderly population, where it is estimated that half of the population above the age of 75 have some form of hearing loss. Young children may also experience hearing loss, most
often due to fluid accumulation or infection in the middle ear. Less commonly, it may be due to a congenital (at birth) problem or after a viral illness in early childhood. Regardless of age, hearing loss can interfere with communication with others on a daily basis. Types of Hearing Loss A conductive hearing loss occurs when there is a breakdown in the conversion of sound waves into movements of the eardrum and the small bones in the middle ear. This can occur either because the sound waves are not reaching the eardrum, e.g. earwax blocking the ear canal, or because the vibrating mechanisms of the eardrum or the middle ear are not functioning properly, e.g. middle ear infections. A sensorineural hearing loss is due to a problem of the inner ear or the auditory nerve. Again there can be many causes, the
most common being hearing loss due to ageing, also known as presbyacusis, which usually affects both ears to a similar degree and can be associated with noises in the ear (tinnitus). Other causes of sensorineural hearing loss include viral infections, trauma, exposure to loud noises, giddiness, side effects from certain medications and congenital causes. In general, sensorineural hearing loss is irreversible and permanent, although partial or total recovery is possible in a few cases. Very rarely, sensorineural hearing loss can be due to a tumour on the auditory nerve. The main difficulty with sensorineural hearing loss is an inability to hear conversations clearly, especially when there is background noise. Many people complain that they can hear the sounds of conversations, but cannot make out exactly what is being said. It can lead to immense frustration and feelings of isolation.
Whilst there is no absolute cure for sensorineural hearing loss, hearing aids are an effective solution for many people. Hearing aids amplify and modulate surrounding sounds to make them more accessible for hearing impaired people, thereby improving their communication ability and increasing their confidence to interact with people around them. When to Seek Advice You should always see a doctor urgently if you have a sudden hearing loss, as it is usually critical to start treatment within 48 hours of its onset. If you notice a hearing loss only in one ear, you should see a doctor as soon as you can, who may refer you to an ENT specialist. If you, or people around you, notice a gradual deterioration in your hearing, you should seek advice from a doctor or an audiologist, who will advise you on the appropriate actions to be taken.
Yishun Health is a network of medical institutions and health facilities of the National Healthcare Group. Admiralty Medical Centre • (65) 6807 8000 • www.admiraltymedicalcentre.com.sg Khoo Teck Puat Hospital • (65) 6555 8000 • www.ktph.com.sg Yishun Community Hospital • (65) 6807 8800 • www.yishuncommunityhospital.com.sg The information is correct at the time of printing and subject to revision without further notice.
ENT.DE.02.0517