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The audiological findings in Ménière's disease are reviewed particularly in respect of loudness recruitment and speech discrimination loss. Although recruitment is pathognomonic of all cochlear lesions, certain distinguishing features are apparent in Ménière's disease which differ from those in other non-metabolic disorders of the cochlea. With mild degrees of hearing loss, recruitment appears to aid speech discrimination supporting the suggestion that it represents the ears adjustment to failing hearing. With more profound degrees of hearing loss, there is a linear inverse relationship between maximum discrimination score and hearing level. Actual hearing aid gains preferred by patients correlate well with those predicted from a consideration of recruitment curves.

A variety of experimental situations are described concerning optokinetic nystagmus and tracking movements of the eyes, which have shown that in certain circumstances the peripheral retina can exert a powerful influence upon the resultant response. The teleological significance of the findings is discussed in the context of the mechanisms subserving ocular-following movements.

The tone decay test was carried out upon normal subjects and patients with a variety of pathological conditions. With normal hearing and conductive deafness, tone decay termed type I was minimal and never exceeded 15-dB. In endorgan deafness type I predominated but a few exhibited slightly greater decay termed type II. Type IV, in which the threshold elevation was severe and rapid, was a characteristic finding in 15 subjects with nerve fiber lesions, including 12 with cerebellopontile angle tumors. Of 52 patients with brain stem lesions a well marked, but slow rate, tone decay type III, was found in a significant proportion including a number with normal hearing. In the latter, good correlation was established between lateralization of the lesion effected by the caloric and the tone decay tests.