Speech-perception-in-noise deficits in dyslexia.
Speech perception deficits in developmental dyslexia were investigated in quiet and various noise conditions. Dyslexics exhibited clear speech perception deficits in noise but not in silence. Place-of-articulation was more affected than voicing or manner-of-articulation. Speech-perception-in-noise deficits persisted when performance of dyslexics was compared to that of much younger children matched on reading age, underscoring the fundamental nature of speech-perception-in-noise deficits. The deficits were not due to poor spectral or temporal resolution because dyslexics exhibited normal 'masking release' effects (i.e. better performance in fluctuating than in stationary noise). Moreover, speech-perception-in-noise predicted significant unique variance in reading even after controlling for low-level auditory, attentional, speech output, short-term memory and phonological awareness processes. Finally, the presence of external noise did not seem to be a necessary condition for speech perception deficits to occur because similar deficits were obtained when speech was degraded by eliminating temporal fine-structure cues without using external noise. In conclusion, the core deficit of dyslexics seems to be a lack of speech robustness in the presence of external or internal noise.
Ziegler
Johannes C
JC
Département de Psychologie, Aix-Marseille Université, Marseille, France. Johannes.Ziegler@univ-provence.fr
Pech-Georgel
Catherine
C
George
Florence
F
Lorenzi
Christian
C
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D001288:Attention / Q000502:physiology; D001308:Auditory Perceptual Disorders / Q000209:etiology*; D002648:Child; D004410:Dyslexia / Q000150:complications*; D005260:Female; D006801:Humans; D007807:Language Tests; D008297:Male; D008568:Memory / Q000502:physiology; D009483:Neuropsychological Tests; D009622:Noise; D010470:Perceptual Masking; D010700:Phonetics; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D011930:Reaction Time; D011932:Reading; D012684:Sensory Thresholds / Q000502:physiology; D013018:Sound Spectrography; D013067:Speech Perception / Q000502:physiology*; D013068:Speech Production Measurement