Frequency following response evoked by vibratory stimuli in profoundly deaf subjects

A vibratory stimulus at a frequency of about 100 Hz was transmitted through a bone conductor on the mastoid in 26 profoundly deaf subjects. In all of them, the function of the vestibular apparatus was tested by means of the Fitzgerald-Hallpike caloric test. In some of the deaf subjects, evoked potentials were recorded, which following the frequency of the stimulus and which according to amplitude and latency characteristics, corresponded to the frequency following response (FFR). A close correlation was found between the normal function of the vestibular apparatus and the appearance of FFR in deaf subjects. The possible receptors of the stimulus and the afferent pathways which generate the recorded response are discussed.