[Early potentials evoked by acoustic stimuli: further results (author's transl)].

The research work carried out during the last years explains only partially the true nature of the short-latency (less than 50 ms) auditory evoked responses (PEP) in man. Widespread support is given to the hypothesis suggesting a double origin: myogenic and cortical with varying predominance between the two according to the position of the active electrodes and the stimulation parameters. PEP appears to have different characteristics according to the electrode coupling, i.e. inion-lobe, vertex-parietal, and vertex-mastoid. Experiments carried out on normally hearing subjects, on subjects with normal hearing but with marked vestibular signs, and on subjects with severe hearing loss and normal vestibular findings show that the presence of auditory function is one of the essential conditions for the generation of the PEP. Conversely, no influence on PEP is apparent following simultaneous and bilateral inhibition of the steady action potential of the ampullary nerve. Whichever the theoretical origin of the PEP is, it may be concluded that, since the results obtained during the clinical work are still incomplete and controversial, it is not possible to consider the PEP as a true expression of the vestibular function.