Laboratoire des Systèmes Perceptifs
Amplitude (AM) and frequency (FM) modulation are dynamic acoustic features known to play a crucial role in speech recognition. The aim of this research internship is to characterize the decision strategies used by normal-hearing subjects in an auditory AM and FM detection task. This will be achieved using a psychophysical method based on the inverse correlation principles, and allowing to build the classification image (or "template") used by the subject during the task. Modeling work suggests that AM and FM are processed by distinct auditory mechanisms, with the subjects listening to the cues evoked modulation in 'off-frequency' frequency channels (in an audio-frequency band different from that corresponding to the audio frequency of the signal acting as a carrier). Specifically, subjects listen for modulation cues in a frequency region above the carrier frequency in the case of AM, and below the carrier frequency in the case of FM. This psychophysical protocol will test these hypotheses related to off-frequency listening.
Joosten, E.R.M., Shamma, S.A., Lorenzi, C., & Neri, P. (2016). Dynamic reweighting of auditory modulation filters. PLOS computational Biology, 12(7). doi: 10.1371/journal.pcbi.1005019.