Hearing impairment, deafness, or hearing loss refers to the total or partial inability to hear sounds. It is estimated that approximately 11 million people in the UK have some type of hearing loss, which makes it the second most common disability in the UK. However, as an invisible disability, it often goes unnoticed, making it easier for those living with hearing loss to be ignored or forgotten.
In this article, Mr Ananth Vijendren, Consultant ENT Surgeon, looks briefly at the different types of hearing loss, consider the impact on people living with hearing impairments and shed light on what the future may hold.
Hearing loss can occur at any age. Around 1 in 1000 children can be born with hearing deficit (termed congenital hearing loss) due to risk factors during pregnancy, childbirth, postpartum or sometimes none at all. These are commonly picked up during the universal newborn hearing screen process and referred to a specialist clinic to investigate the cause and help guide treatment.
During adolescence and adulthood, hearing can be affected from trauma, medications (eg. aminoglycoside antibiotics, platinum-based chemotherapy), brain infections and the development of chronic middle ear diseases such as Eustachian tube dysfunction, cholesteatoma (abnormal, noncancerous skin growth) and otosclerosis (abnormal bone growth inside the ear).
In the later stages of life, the cells and nerves within the cochlea, our hearing organ, gradually deteriorate and can give rise to a high-frequency sensorineural hearing loss termed presbyacusis. This process is sometimes accelerated by pre-existing generic conditions and environmental factors (eg. repeated loud noise exposure, repeated ear infections).
There are three main types of hearing loss:
- Conductive hearing loss (CHL): This is a failure of the sound to reach the inner ear due to issues within the outer and middle ears. Common causes include infections, wax obstruction, ear drum perforation and chronic middle ear disease (eg. cholesteatoma)
- Sensorineural hearing loss (SNHL): This occurs as a result of an impairment to structures of the inner ear such as the cochlea, balance organs, hearing nerves or hearing pathway to the brain. It can arise as a result of hereditary and acquired causes (eg. trauma, medications). Although most SNHL are gradual, a sudden SNHL is a medical emergency for which you should see an ENT doctor as soon as possible to diagnose, start treatment and help reverse the condition.
- Mixed hearing loss (MHL): This is a combination of both CHL and SNHL and occurs as a result of conditions that affect the outer, middle and inner ears. There is generally more than one cause to a MHL.
The impact of hearing loss
Living with hearing loss can be very debilitating. Many people find it very isolating that they are unable to pick up conversations in a group making them feel embarrassed and reclusive. Moreover, people with hearing loss find it harder to hear in the presence of background sounds. This has implications when working in noisy environments (eg factories and building trade) or even in household conversations, which can lead to irritation of either the speaker or listener and result in domestic arguments. Although a variety of aiding techniques and procedures are present, a large proportion of people still associate them with a historical stigma that these devices are big, bulky and are unsightly if used in or around the ear.
Besides the social repercussions, hearing loss can also have damaging effects on one’s health. Experts from the John Hopkins Institute in the US tracked 639 adults for nearly 12 years and found that mild hearing loss doubled the risk of dementia while moderate hearing loss increased the risk three-fold and severe hearing loss increased it five-fold.
The treatment for hearing loss very much depends on the type, cause and severity. Patients with mild to moderate hearing loss and presbyacusis can derive good benefit from hearing aids. Many of the aids are small and cosmetically hidden with the ability to connect to smartphone and tablet devices. In some patients, surgical treatment could be the better choice, either in the form of grommets, eardrum repair, removal of disease from the middle ear or reconstruction of the bones of hearing (ossiculoplasty / stapedotomy).
Patients who still struggle with their hearing despite hearing aids or previous surgery may be a candidate for implantable hearing devices such as bone-conducting hearing implants, middle ear implants or a cochlear implant.
Historical treatments for sensorineural and mixed hearing losses have always targeted the outcome of the process. The future lies in targeting the cause. Various studies are underway to look at preventing and reversing hearing loss. Researchers from Israel and the US have been looking at gene therapy to see if defective parts of the inner ear hearing organ can be reversed and regrown. Within the UK, the REGAIN trial is currently underway looking at the role of gamma-secretase inhibitors in regenerating hair cells. The SeaSheL national prospective cohort study is investigating the likeliest cause and most successful treatment in sudden SNHL.
About Mr Vijendren
At Highgate hospital, Mr Vijendren is happy to see anyone who has concerns about their hearing. During the consultation, Mr Vijendren will spend time listening to your worries and employ a patient-centred history and examination to help identify the type and cause of your hearing loss. With the availabilities of audiograms and scans, Mr Vijendren can help direct you to the best treatment option for your hearing. You can find out more about Mr Vijendren here.