Hearing Loss And Audiometry Flashcards
What is the best test for differentiating between conductive and sensorineural hearing loss?
Rinne (tuning fork held outside ear for air conduction then on the mastoid for bony conduction).
Normally air conduction is better than bony conduction.
What are some risk factors for congenital deafness?
Genetic predisposition Down syndrome Maternal intrauterine infection Drug ingestion during pregnancy Birth trauma Haemolytic disease of the newborn
What’s a sign of normal hearing at 1 month?
Should notice sudden constant sounds eg vacuum cleaner by pausing and listening
What’s a sign of normal hearing at 3 months?
Should respond to loud sound eg will stop crying when hands clapped
What’s a sign of normal hearing at 4 months?
Should turn head to look for source of sound eg mother speaking behind child
What’s a sign of normal hearing at 7 months?
Should turn instantly to voices
What’s a sign of normal hearing at 10 months?
Should listen out for familiar sounds
What’s a sign of normal hearing at 12 months?
Should show some response to familiar sounds including his/ her name
What is the difference between conductive and sensorineural hearing loss?
Conductive hearing loss is caused by an abnormality in the pathway conducting sound waves from the outer ear to the inner ear, as far as the foot plate of the stapes.
Sensorineural hearing loss is a defect central to the oval window involving the cochlear (sensory), cochlear nerve (neural), or more rarely central neural pathways.
What is otosclerosis?
Disease of the bone surrounding the inner ear and the most common cause of conductive hearing loss.
It is a progressive disease that usually develops in 20s and 30s.
Autosomal dominant with female preponderance
Associated with tinnitus
Require referral to ENT for stapedectomy
What is a cholesteatoma?
A sac of keratinising squamous epithelium that arises from a perforation involving the periphery of the tympanic membrane. Surgical correction is mandatory.
