A baby's hearing is screened using Automated Auditory Brainstem Response (AABR), Otoacoustic Emissions (OAE), or both. Screening only takes a few minutes. In most cases, you can stay with your baby while the screening is done.
Otoacoustic Emissions (OAE) If the part of the ear called the cochlea is normal, it produces sound in response to external stimulation, which is what is measured during the OAE test. To measure OAEs, a small probe is placed in the infant’s ear canal and sound is presented by either one or two tiny speakers. Any response produced by the ear is recorded with a small microphone that is inside the probe. If cochlear hearing loss exists, the cochlea either will not generate a response or it will generate a response that falls below the level that is expected from an ear with normal hearing.
Automated Auditory Brainstem Response (AABR) The normal ear-to-brain connection creates small electrical currents when excited. AABR tests measure these electrical responses through small surface electrodes placed on the baby’s head.. An earphone is placed in the ear, brief sounds are played, and the electrical signals across the electrodes are recorded. If hearing is normal, these signals should be observed for low-level stimuli. If hearing loss exists, these signals will only occur after higher levels of stimuli. Compared to OAE tests, AABRs are less dependent on the status of the middle ear because the response is recorded across surface electrodes and does not have to travel back out through the middle and external ear.