Confirmation of G. von Bekesy's theory of paradoxical wave propagation along the cochlear partition by means of bone-conducted auditory brainstem responses

In order to investigate the propagation time of the traveling wave in the c ochlea after boneconduction stimulation of the inner ear, bone-conducted au ditory brainstem responses (ABRs) were recorded in 6 normally hearing subje cts after masking the basal cochlear region using high-pass filtered noise. As in air-conducted ABRs, Jewett V wave latency is delayed corresponding t o the propagation time of the traveling wave front traversing the desynchro nized hair cell region. These results support the theory of paradoxical wav e propagation proposed by von Bekesy in 1952, who postulated that wave moti on always starts from the stiffest part of the basilar membrane, independen t of the location of the vibrating force, in addition, we also found a late ncy delay of the Jewett V wave of bone-conducted ABRs in 8 patients with hi gh-frequency hearing loss which corresponded to the severity of their heari ng impairment. Copyright (C) 2000 S. Karger AG, Basel.