[Objective audiometry by recording of early and middle-latency auditory evoked potentials using an external method].

The bio-electric potentials induced by a stimulus in the cochlea and the various structures of the auditory pathways of the brain stem and the primary auditory cortex may be collected using an external method. The authors frequently emply in clinical practice early components, which correspond to the cochlea response in the cochlear nucleus of the medulla, in the olive of the pons and the posterior quadrigeminal tubercle, and middle latency components, sub-cortico-cortical potentials generated in the thalamus and the primary auditory cortex. Combined use of early and middle latency components makes it possible, without preparation and with simple sedation in the child, to obtain an objective determination of threshold. In oto-neurology, this examination provides appraciable information concerning lesions in the auditory pathways: acoustic neuroma, brain stem tumour, multiple sclerosis, central deafness in patients with cerebral motor insufficiency.