Detecting a hearing impairment in children can be difficult.
In the UK there is a system in place to screen for deafness at birth. This is usually performed either in a hospital or in the community with objective hearing tests. These tests are either an otoacoustic emission or an automated auditory brainstem response.
The otoacoustic emission test indicates if the cells within the cochlear are functioning normally, and the auditory brainstem response assesses the integrity of the auditory pathway.
Subjective assessments of hearing can be difficult in infants. Until a child is able to move their head, the only indication of hearing difficulties is if they do not startle in response to a loud noise. As children get older, it becomes easier to subjectively assess their hearing:
at about 3 months when a child starts to turn their head, then this gives more indication whether they are able to respond reliably to sound
until the age of 3 and a half, play or visually reinforced audiometry are used to assess hearing thresholds
after 3 and a half pure tone audiograms can be reliably performed