Auditory Evoked Potentials
This test measures the velocity of the sound on its journey from the inner ear to the hearing centres of the brain. It does not require the co-operation of the patient. Wide-spectrum sound (white noise) is delivered via headphones to the ear, while special electrodes, fixed in specific points on the skull, record the time of arrival of the sound at five stations beyond the organ of hearing, on its way to the brain higher centres.
Auditory Evoked potentials are a sensitive test. They can identify pathology of the auditory nerve, before it is recognizable on the CT-scan or the MRI. Furthermore, they are the only means available today for quantitative measurement of hearing in infants and small chidren, being our main tool in the assessment of the child deafness.