Objective assessment of hearing disorders with the aid of 40 Hertz middle latency responses in speech frequencies

We applied the 40 Hz ERP technique described by R. Galambos to about thirty adults suffering from perception auditory deficiency. We aimed at objectively evaluating their hearing. Our statistical results show that 40 Hz recorded through a logon is a good way to establish the threshold level in the speech frequencies. They also show that the amplitude of the recorded potential is higher when a ear lobe-forehead derivation (A1 or A2/Fz) is used. It has not been possible to give prominence to abnormal amplitude enhancement at supra-threshold level by the recruiting subjects. This method could have a great interest in sham or forensic evidence problems.