Auditory brainstem responses and extratympanic electrocochleography. A threshold comparison in children.

Electrocochleography (ECoG) and auditory brainstem response (ABR) have been recorded simultaneously in 23 children referred for threshold evaluation. The ECoG electrode is an extratympanic silver ball (Life-Tech) whereas the ABR is recorded with Ag-AgCl surface electrodes. Of the 30 ears investigated according to this protocol, 11 had no response with either technique, and in a further 11 no difference was found between ECoG and ABR thresholds. In the remaining 8 ears, ABR threshold was lower in 6 and the ECoG in 2. We conclude that the extra time needed for cleansing the ear canal and inserting the electrode does not justify the use of ECoG in threshold evaluations, since the ABR alone has the necessary sensitivity.