Which People with Specific Language Impairment have Auditory Processing Deficits?

Abstract

An influential theory attributes developmental disorders of language and literacy to low-level auditory perceptual difficulties. However, evidence to date has been inconsistent and contradictory. We investigated whether this mixed picture could be explained in terms of heterogeneity in the language-impaired population. In Experiment 1, the behavioural responses of 16 people with specific language impairment (SLI) and 16 control listeners (aged 10 to 19 years) to auditory backward recognition masking (ABRM) stimuli and unmasked tones indicated that a subgroup of people with SLI are less able to discriminate between the frequencies of sounds regardless of their rate of presentation. Further, these people tended to be the younger participants, and were characterised by relatively poor nonword reading. In Experiment 2, the auditory event-related potentials (ERPs) of the same groups to unmasked tones were measured. Listeners with SLI tended to have age-inappropriate waveforms in the N1-P2-N2 region, regardless of their auditory discrimination scores in Experiment 1. Together, these results suggest that SLI may be characterised by immature development of auditory cortex, such that adult-level frequency discrimination performance is attained several years later than normal.

Computer‐based auditory training (CBAT): benefits for children with language‐ and reading‐related learning difficulties

“…However, the 'rapid auditory processing deficit' theory is not universally accepted because there is growing evidence that auditory temporal processing deficit does not underpin LLI or SRD in all individuals (see Bailey and Snowling, 17 Griffiths et al, 18 and McArthur and Bishop.) 19 Effect of FFW intervention on language, phonological awareness, reading, and spelling skills of children Of the 13 studies shown in Table I, 10 studies (including the studies by Gaab et al 20 and Temple et al, 21 associates of the FFW developers) reported a positive effect of training in at least one of the following outcome measures: language, phonological awareness, or reading skills. However, the results should be viewed with caution because not all of them reflect a genuine training effect.…”

Specific language impairment as systemic developmental disorders

“…Recent work (Bishop, Carlyon, Deeks, & Bishop, 1999) has demonstrated that this cannot explain all dysphasic behaviours, but problems processing fast sound changes could be among the features that lead to SLI in a child. Other authors (McArthur & Bishop, 2002;McArthur & Bishop, 2004) have proposed an alternative to this deficit, namely difficulty with frequency discrimination. One characteristic of this behaviour is that it changes with age.…”

Auditory Processing in Children with Specific Language Impairments: Are there Deficits in Frequency Discrimination, Temporal Auditory Processing or General Auditory Processing?

“…In contrast to the aforementioned hypothesis, people with SLI exhibited problems in specific auditory functions , showing poorer abilities in the following tasks as compared to NDCs: FD of tones in behavioral tests and ERPs [14][15][16] , intensity discrimination of tones in behavioral tests [17] , differentiation between two different and fixedfrequency tones without using a time-processing paradigm in both behavioral tests [18] and MMN [e.g., 19], and FD for long as well as short interstimulus intervals in children with SLI in behavioral tests [4,6] . Furthermore, researchers have identified significant moderate to strong correlations between FD scores and phonological/speech skills [15] . Reduced abilities in FD may affect discrimination and identification of spectral patterns of speech sounds, and these abilities influence the development of neural representations for the different phonemes during language development [5] .…”

“…The contradictory findings of NVA processing tasks in children with SLI do not clearly support or undermine any one of the described hypotheses, and further, this contradiction might be explained by: -insufficient study population size, with no more than 17 participants in any SLI group [2, 6-8, 14-17, 20] while only a few study populations included 25 participants or more [3,4] ; -too broad an age range, between 10 or 12 and 20 years [14][15][16] ; -examination of only one or two different aspects of NVA abilities [4,6,14,18] . Only a few authors have investigated three or more different aspects in children with SLI as compared to NDC subjects.…”