Temporal modulation of the four-peaked longitudinal structure of the equatorial ionosphere by the 2 day planetary wave

2010 ◽  
Vol 115 (A12) ◽  
pp. n/a-n/a ◽  
Author(s):  
Guiping Liu ◽  
Thomas J. Immel ◽  
Scott L. England ◽  
Karanam K. Kumar ◽  
Geetha Ramkumar
Keyword(s):  
Planetary Wave ◽  
Equatorial Ionosphere ◽  
Temporal Modulation ◽  
Longitudinal Structure

scholarly journals Temporal modulations of the longitudinal structure inF2peak height in the equatorial ionosphere as observed by COSMIC

2010 ◽  
Vol 115 (A4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Guiping Liu ◽  
Thomas J. Immel ◽  
Scott L. England ◽  
Karanam K. Kumar ◽  
Geetha Ramkumar
Keyword(s):  
Equatorial Ionosphere ◽  
Longitudinal Structure

Modal Analysis of Turbulent Flow near an Inclined Bank–Longitudinal Structure Junction

2021 ◽  
Vol 147 (3) ◽  
pp. 04020100
Author(s):  
Nasser Heydari ◽  
Panayiotis Diplas ◽  
J. Nathan Kutz ◽  
Soheil Sadeghi Eshkevari
Keyword(s):  
Turbulent Flow ◽  
Modal Analysis ◽  
Longitudinal Structure

scholarly journals Mechanisms of Spectrotemporal Modulation Detection for Normal- and Hearing-Impaired Listeners

2021 ◽  
Vol 25 ◽  
pp. 233121652097802
Author(s):  
Emmanuel Ponsot ◽  
Léo Varnet ◽  
Nicolas Wallaert ◽  
Elza Daoud ◽  
Shihab A. Shamma ◽  
...  
Keyword(s):  
Speech Intelligibility ◽  
Hearing Impaired ◽  
Temporal Modulation ◽  
Computational Tools ◽  
Cochlear Tuning ◽  
Cochlear Hearing Loss ◽  
Nonlinear Processing ◽  
Linear Band ◽  
Band Pass ◽  
Modulation Filter

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.

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