Deafness refers to the loss of the ability to hear normally. There are two main types of hearing loss: conductive and sensorineural. These can occur separately or together, in which case it is called mixed loss. Hearing loss can affect one (unilateral) or both ears (bilateral) to varying degrees. Most cases of sensorineural hearing loss do not respond to medical treatment and are typically managed with hearing aids or cochlear implants.
Congenital hearing loss is present at birth. It is now recommended that hearing be tested for every newborn to detect hearing loss early. Early diagnosis and treatment are crucial for the development of normal speech and language functions. If hearing loss is detected late, the brain regions responsible for hearing may adapt to other functions, making surgical outcomes less effective. Newborns are screened using Otoacoustic Emissions (OAE) to ensure early detection.
Hearing loss can either be congenital or acquired. Common causes include:
Congenital causes:
Acquired causes:
Mild hearing loss can be hard to detect. Early signs that may indicate hearing loss include:
Early diagnosis of hearing loss is essential for effective treatment. A thorough examination of the ears and simple hearing tests can identify many common causes. Diagnostic tools include:
Every newborn undergoes a hearing screening test before hospital discharge. Infants who do not pass the screening are referred for additional tests like ABR/BAER and ASSR. These tests help identify hearing loss early, ensuring timely intervention.
Audiometry is the technique used to measure hearing ability. During the test, pure tones of controlled intensity are played, and the minimum volume required to hear each tone is recorded. A bone oscillator may also be used to test bone conduction. Audiometry can detect early-stage hearing loss caused by factors like acoustic trauma, chronic infections, or medication-induced hearing loss.
ABR (also called BERA) is a non-invasive test that records the electrical potentials generated by the auditory pathway. Electrodes are placed on the forehead and ears to measure brainstem responses to sound stimuli. This test typically takes 60-120 minutes and is used to diagnose hearing loss and neurological issues.
Treatment depends on the type and cause of hearing loss. Some options include:
Treatment for hearing loss can significantly improve quality of life by: