Which spectral cues underlie the perceptual processing of smiles in speech? Here, the question was addressed using reverse-correlation in the case of the isolated vowel [a]. Listeners were presented with hundreds of pairs of utterances with randomly manipulated spectral characteristics and were asked to indicate, in each pair, which was the most smiling. The analyses revealed that they relied on robust spectral representations that specifically encoded vowel's formants. These findings demonstrate the causal role played by formants in the perception of smile. Overall, this paper suggests a general method to estimate the spectral bases of high-level (e.g., emotional/social/paralinguistic) speech representations.
9 September 2013 in The Journal of the Acoustical Society of America
Using molecular psychophysics, temporal loudness weights were measured for 2-s, 1-kHz tones with flat, increasing and decreasing time-intensity profiles. While primacy and recency effects were observed for flat profile stimuli, the so-called “level dominance” effect was observed for both increasing and decreasing profile stimuli, fully determining their temporal weights. The weighs obtained for these profiles were basically zero for all but the most intense parts of these sounds. This supports the view that the “level dominance” effect is prominent with intensity-varying sounds and that it persists over time since temporal weights are not affected by the direction of intensity change.
23 January 2015 in Attention, Perception, & Psychophysics
Spectrotemporal modulations (STM) are essential features of speech signals that make them intelligible. While their encoding has been widely investigated in neurophysiology, we still lack a full understanding of how STMs are processed at the behavioral level and how cochlear hearing loss impacts this processing. Here, we introduce a novel methodological framework based on psychophysical reverse correlation deployed in the modulation space to characterize the mechanisms underlying STM detection in noise. We derive perceptual filters for young normal-hearing and older hearing-impaired individuals performing a detection task of an elementary target STM (a given product of temporal and spectral modulations) embedded in other masking STMs. Analyzed with computational tools, our data show that both groups rely on a comparable linear (band-pass)–nonlinear processing cascade, which can be well accounted for by a temporal modulation filter bank model combined with cross-correlation against the target representation. Our results also suggest that the modulation mistuning observed for the hearing-impaired group results primarily from broader cochlear filters. Yet, we find idiosyncratic behaviors that cannot be captured by cochlear tuning alone, highlighting the need to consider variability originating from additional mechanisms. Overall, this integrated experimental-computational approach offers a principled way to assess suprathreshold processing distortions in each individual and could thus be used to further investigate interindividual differences in speech intelligibility.
21 April 2025 in Journal of the Association for Research in Otolaryngology
The way the visual system processes different scales of spatial information has been widely studied, highlighting the dominant role of global over local processing. Recent studies addressing how the auditory system deals with local–global temporal information suggest a comparable processing scheme, but little is known about how this organization is modulated by long-term musical training, in particular regarding musical sequences. Here, we investigate how non-musicians and expert musicians detect local and global pitch changes in short hierarchical tone sequences structured across temporally-segregated triplets made of musical intervals (local scale) forming a melodic contour (global scale) varying either in one direction (monotonic) or both (non-monotonic). Our data reveal a clearly distinct organization between both groups. Non-musicians show global advantage (enhanced performance to detect global over local modifications) and global-to-local interference effects (interference of global over local processing) only for monotonic sequences, while musicians exhibit the reversed pattern for non-monotonic sequences. These results suggest that the local–global processing scheme depends on the complexity of the melodic contour, and that long-term musical training induces a prominent perceptual reorganization that reshapes its initial global dominance to favour local information processing. This latter result supports the theory of “analytic” processing acquisition in musicians.