Diagnostic Significance of PB Word Functions

Abstract

Performance-Intensity (PI) functions for phonetically balanced (PB) words were compared in 41 patients with presumably cochlear disorder and 16 patients with retrocochlear disorder. The PI functions of all of 10 eighth nerve disorders and three of six brain stem disorders showed a pronounced rollover phenomenon. After reaching a maximum the PI function declined substantially with further increase in speech level. Implications of the phenomenon for differential diagnosis of cochlear and retrocochlear disorders are discussed.