BERA Hearing Test
BERA “OR” Brainstem Evoked Response Audiometry
BERA hearing test clinic in Delhi
How is the BERA test conducted?
Bera is an objective mean of eliciting brain stem potentials in response to audiological stimuli which mostly click stimuli. Electrodes help to record these potentials which are placed on the scalp. BERA is an effective screening tool for evaluating cases of hearing loss due to retrocochlear pathology i.e. (Acoustic schwannoma). MRI scan may be indicated if there is an Abnormal BERA in such cases. BERA test should be supplemented by other audiological test battery to know the site of lesion and plan management accordingly.
- Used in screening newborns for deafness
- Used for intra-operative monitoring of central and peripheral nervous system
- Monitoring patients in intensive care units
- Diagnosing suspected demyelinated disorders
This graph shows example of BERA test done at high intensity which is 100dBnHL and there is no response present as we can see the is no visible 5th wave which means that the auditory stimulus which is travelling is brainstem is not able to stimulate even at 100 dBnHL.
These finding needs to be always supplemented with other test like OAE and ASSR, also with Behavioural observations.
What is BERA Test?
BERA is hearing test in which sounds given through the ear. In BERA test child should be sedated first, after sleep Audiologist place electrodes through gel. BERA test will take 30 min after sleeping but in case of full audiological evaluation (ASSR, BERA, Tympanometry, OAE ) it will take 1 Hour.
In BERA test sound will start at 90 dB and decreases 10 dB till 30 dB (normal hearing ). We see wave Vth for hearing if wave Vth not seen till 30dB means hearing problem is there
When a sound reaches the ear, it passes through the external ear canal and vibrates the eardrum. These vibrations are conducted by three small bonus in the middle ear, the malleus, incus and stapes to the inner ear. The inner ear contains the cochlea, which plays an important role in hearing