BASILAR-MEMBRANE ACTIVITY AND LOUDNESS
Buus and Florentine (ISP meeting 2001) presented evidence that basilar-membrane velocity growth functions are proportional to the square root of loudness functions derived from temporal and spectral integration. Although it is not possible to directly measure basilar- membrane activity in humans, it is likely that tone-burst otoacoustic emission input-output functions, at least at low and moderate levels, are closely related to the amount of basilar- membrane activity. To further examine this relation, tone-burst otoacoustic emissions are compared with loudness functions derived from a combination of data from temporal integration of loudness and spectral loudness summation, as well as loudness functions that are more directly measured using cross-modality matching. Tone-burst otoacoustic emission input-output functions show a strong correspondence to loudness measured using all these methods. These findings support the idea that loudness is closely related to basilar- membrane activity and that tone-burst otoacoustic emissions may provide rapid, non-invasive insight into cochlear activity.