Deficits in speech perception predict language learning impairment

Abstract

Specific language impairment (SLI) is one of the most common childhood disorders, affecting 7% of children. These children experience difficulties in understanding and producing spoken language despite normal intelligence, normal hearing, and normal opportunities to learn language. The causes of SLI are still hotly debated, ranging from nonlinguistic deficits in auditory perception to high-level deficits in grammar. Here, we show that children with SLI have poorer-than-normal consonant identification when measured in ecologically valid conditions of stationary or fluctuating masking noise. The deficits persisted even in comparison with a younger group of normally developing children who were matched for language skills. This finding points to a fundamental deficit. Information transmission of all phonetic features (voicing, place, and manner) was impaired, although the deficits were strongest for voicing (e.g., difference between͞b͞and͞p͞). Children with SLI experienced perfectly normal ''release from masking'' (better identification in fluctuating than in stationary noise), which indicates a central deficit in feature extraction rather than deficits in low-level, temporal, and spectral auditory capacities. We further showed that speech identification in noise predicted language impairment to a great extent within the group of children with SLI and across all participants. Previous research might have underestimated this important link, possibly because speech perception has typically been investigated in optimal listening conditions using non-speech material. The present study suggests that children with SLI learn language deviantly because they inefficiently extract and manipulate speech features, in particular, voicing. This result offers new directions for the fast diagnosis and remediation of SLI.phonetic deficit ͉ auditory deficit ͉ speech intelligibility ͉ masking noise ͉ specific language impairment M any children experience unexpected difficulties in understanding and producing spoken language despite normal intelligence, normal hearing, normal opportunities to learn language, and in the absence of any obvious neurological problems (for review, see ref. 1). This disorder is typically called specific language impairment (SLI). In the past years, research on SLI has experienced a growth of interest partially because it has become clear that more children than initially thought show language learning difficulties. Indeed, recent epidemiological studies estimate the incidence of SLI to be Ϸ7.4% in a population of monolingual English-speaking kindergarten children (2). Children with SLI exhibit deficits in several aspects of language, including phonology, morphology, and syntax (1, 3). One of the hallmarks of SLI is a deficit in the use of function morphemes (e.g., the, a, and is) and other grammatical morphology (e.g., plural -s, past tense -ed). Children with SLI also are at high risk for subsequent literacy problems (4).The causes of SLI are still hotly debated. Current theories of SLI fall into two categ...

Musical Experience Limits the Degradative Effects of Background Noise on the Neural Processing of Sound

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Developmental dyslexia: an update

“…It has a recurrence risk of approximately 4.52 for spelling and reading, as demonstrated by single proband sib-pair design, and a one standard deviation discrepancy criterion (Ziegler et al 2005a). The clinical features of dyslexia may overlap with other disorders, such as language learning disability (Vicari et al 2005;Ziegler et al 2005b), alexia (acquired reading disorder), hyperlexia, and attentiondeficit hyperactivity disorder (ADHD). However, none of these disorders involve phonologic deficits similar to dyslexia (Shaywitz 1998). impairment is unknown.…”

Perceptual Confusions Among Consonants, Revisited—Cross-Spectral Integration of Phonetic-Feature Information and Consonant Recognition

“…Apart from articulatory-acoustic-phonetic studies of the speech signal (e.g., [25]), there is little independent evidence for their objective, (i.e., neurological) existence. Despite this, the PF-based framework has been productive as a working hypothesis for speech research over the intervening period (e.g., [41]- [43] and [53], [54]). Another criticism is that MN55 used an unconventional feature representation.…”

“…Since the publication of MN55, PFs have been used to investigate central processes underlying consonant recognition (e.g., [41]- [43], but see [13]). However, these studies did not directly investigate the cross-spectral perceptual integration of PFs, the focus of our paper.…”