Hearing Screening

Hearing testing in children

The table below summarises the hearing tests which may be performed on children

Age	Test	Comments
Newborn	Otoacoustic emission test	All newborns should be tested as part of the Newborn Hearing Screening Programme. A computer-generated click is played through a small earpiece. The presence of a soft echo indicates a healthy cochlea
Newborn & infants	Auditory Brainstem Response test	May be done if otoacoustic emission test is abnormal
6-9 months	Distraction test	Performed by a health visitor, requires two trained staff
18 months - 2.5 years	Recognition of familiar objects	Uses familiar objects e.g. teddy, cup. Ask child simple questions - e.g. 'where is the teddy?'
> 2.5 years	Performance testing	-
> 2.5 years	Speech discrimination tests	Uses similar-sounding objects e.g. Kendall Toy test, McCormick Toy Test
> 3 years	Pure tone audiometry	Done at school entry in most areas of the UK

As well as the above test there is a questionnaire for parents in the Personal Child Health Records - 'Can your baby hear you?'

Audiogram

Audiograms are usually the first-line investigation that is performed when a patient complains of hearing difficulties. They are relatively easy to interpret as long as some simple rules are followed:

anything above the 20dB line is essentially normal (marked in green on the audiogram below)
in sensorineural hearing loss both air and bone conduction are impaired
in conductive hearing loss only air conduction is impaired
in mixed hearing loss both air and bone conduction are impaired, with air conduction often being 'worse' than bone

This audiogram is essentially normal. Note all the values are above the 20dB line, highlighted in green on this image

Interpretation of an audiogram

Hearing range: <20dB is normal.

Conductive: Normal BC, Reduced AC - on the graph there should be an 'Air bone gap '
SNHL: Both BC and AC reduced, No Air bone gap.

Scenario: 40-yr-old musician c/o problems detecting pitch when he is playing the violin.

You arrange an audiogram: