As a technique of establishing the audibility of test sounds at various frequencies, an
audiogram may include thresholds for the aided audiogram. This testing may be performed
as part of guidance counselling for the purposes of validating the programmed amplification
of a bone conduction aid or cochlear implant, validating that frequency lowering is effective
in a hearing aid, and assessing functional gain when real ear microphone measurements
cannot be obtained.
The method of evaluation known as Aided Cortical Testing is still in its infancy and requires
a great deal of expertise. It is still in the process of being developed as a clinical test, and
most hearing centres do not have the necessary equipment. It can be utilised in situations
where youngsters do not have access to other methods that can provide a reliable
evaluation. During the procedure, electrodes, which are little metal discs, are affixed to the
child’s skull, and speech sounds are played through a speaker at predetermined volumes.
These sounds cause an increase in electrical activity in the brain, and the electrodes are
attempting to pick up on this activity. This is a specific kind of EEG. This allows us to assess
whether or not the sound is being picked up, and it may also inform us how to calibrate a
hearing aid so that it works properly even for a newborn who is very young.
After adjusting the hearing aids to achieve the greatest possible match to the amplification
goals, the audiologist continues to monitor and analyse the fitting to see if specific aspects
require further fine-tuning. This can be accomplished in a variety of ways: