Auditory reverse correlation applied to the study of place and voicing: four new phoneme-discrimination tasks

Auditory reverse correlation (revcorr) is an experimental paradigm that reveals the acoustic cues used by listeners in any auditory task. It has been previously used to explore the categorisation of /aba/ and /ada/ sounds in noise. Here, we extend the paradigm to new phonemic contrasts. In a typical revcorr experiment, one introduces random fluctuations in stimuli in order to measure how they affect the behavioural responses of the participant on a trial-by-trial basis. The outcome is called auditory classification images (ACI), i.e. time-frequency maps of the acoustic cues used by participants, revealing their individual listening strategies in a given task. Here, we use the "fastACI toolbox" [Osses & Varnet, 2021] to apply the paradigm to new phonemic contrasts: /aba/-/apa/ ; /ada/-/aga/ ; /ada/-/ata/ ; /apa/-/ata/. It allows us to study the perception of two phonetic traits: place of articulation and voicing. We present the results of 2 participants for each contrast. The results are consistent with the main auditory cues already identified in the psycholinguistic iterature but they also reveal unexpected secondary cues.