Novel paradigms to Investigate Temporal Fine Structure Processing
Laboratoire des Systèmes Perceptifs, CNRS & Ecole normale supérieure, Paris, France
A wide range of psychophysical studies showed that ageing and cochlear hearing loss impair the neural processing of temporal fine structure (TFS) cues while sparing – to some extent - the processing of temporal-envelope (E) cues. However, the poorer-than-normal scores measured in tasks assessing directly TFS-processing capacities may partly result from reduced “processing efficiency”. The accuracy of neural phase locking to TFS cues may be normal, but the central auditory system may be less efficient in extracting the TFS information. This raises the need to design psychophysical tasks assessing TFS-processing capacities while controlling for or limiting the potential contribution of reduced processing efficiency. Several paradigms will be reviewed. These paradigms attempt to either: (i) cancel out the effect of efficiency (leaving only the temporal factor), (ii) assess TFS-processing capacities indirectly via E-perception tasks where efficiency is assumed to be normal for elderly or hearing-impaired listeners, or (iii) assess TFS-processing capacities indirectly via E-perception tasks designed such that impaired listeners (i.e., elderly or hearing-impaired listeners) should outperform control listeners (i.e., young normal-hearing listeners) if ageing or cochlear damage cause a genuine suprathreshold deficit in TFS encoding. Good candidates in this regard are interference tasks. Pilot data will be presented and discussed.
This work was supported by ANR HEARFIN.