The Effect of Talker and Intonation Variability on Speech Perception in Noise in Children With Dyslexia

Abstract

Purpose-To determine whether children with dyslexia (DYS) are more affected than agematched average readers (AR) by talker and intonation variability when perceiving speech in noise.Method-Thirty-four DYS and 25 AR children were tested on their perception of consonants in naturally-produced consonant-vowel (CV) tokens in multi-talker babble. Twelve CVs were presented for identification in four conditions varying in the degree of talker and intonation variability. Consonant place (/bi/-/di/) and voicing (/bi/-/pi/) discrimination was investigated with the same conditions.Results-DYS children made slightly more identification errors than AR children but only for conditions with variable intonation. Errors were more frequent for a subset of consonants, generally weakly-encoded for AR children, for tokens with intonation patterns (steady and risefall) that occur infrequently in connected discourse. In discrimination tasks, which have a greater memory and cognitive load, DYS children scored lower than AR children across all conditions. Conclusions-Unusual intonation patterns had a disproportionate (but small) effect on consonant intelligibility in noise for DYS children but adding talker variability did not. DYS children do not appear to have a general problem in perceiving speech in degraded conditions, which makes it unlikely that they lack robust phonological representations.

Informational masking of speech in dyslexic children

“…This deficit held true for the three consonant features examined here, which tempers previous finding of a specific impairment of reception of voicing and/or place of articulation in noise in dyslexic individuals (Hazan et al, 2013;Ziegler et al, 2009). Dichotic presentation of the speech target and masker minimized cochlear EM while preserving IM.…”

“…Our recent work suggests that dyslexic children experience difficulties in complex tone sequences inducing pure IM in comparison to both reading level-and age-matched controls (Calcus et al, 2015). In contrast, Messaoud-Galusi et al (2011) and Hazan et al (2013) failed to evidence a deficit in dyslexics presented with a babble noise background. Yet, as there was no attempt to remove its energetic component, the babble noise used in those two studies simultaneously induced EM and IM.…”

“…However, Dole et al (2012) showed that dyslexic adults exhibited preserved perception of speech under SSN, but were impaired when presented with babble noise. Later studies revealed a small but significant deficit of speech discrimination (but not identification) in babble noise (Messaoud-Galusi et al, 2011;Hazan et al, 2013).…”

“…Indeed, phonetic feature analyses have led to contradictory results, some suggesting that reception of place was specifically impaired in dyslexic children (Ziegler et al, 2009), while others pointed at reception of voicing (Hazan et al, 2013). Altogether, determining if the reception of a phonetic trait is specifically affected in noisy backgrounds might be of crucial importance in refining clinical treatment of dyslexic children.…”

A General Audiovisual Temporal Processing Deficit in Adult Readers With Dyslexia

“…Indeed, Hayes et al reported differences between learning-disabled and normal-learning children but only when the stimuli were presented with a high level of noise. Moreover, Hazan, Messaoud-Galusi, and Rosen (2013) showed that children with dyslexia exhibited difficulties in speech-in-noise perception but only when the speaker's intonation was variable or when the listeners were under greater memory and cognitive load as in discrimination tasks. It is also possible that deficits that could emerge in the perception of words or sentences may have gone undetected in the current task with isolated nonsense syllables (e.g., Sommers, Tye-Murray, & Spehar, 2005).…”