Academic journal article Journal of Medical Speech - Language Pathology

Auditory Temporal Resolution in Children with Specific Language Impairment

Academic journal article Journal of Medical Speech - Language Pathology

Auditory Temporal Resolution in Children with Specific Language Impairment

Article excerpt

There are controversies surrounding the issue of temporal auditory processing and specific language impairment (SLI). This article explores the influence of tone frequency on temporal resolution in SLI. The Auditory Fusion Test-Revised (AFT-R) was carried out with 19 children with SLI and 19 control children with normal language development. No between-groups differences in temporal resolution were found for 0.25 and 1 kHz tones, but the SLI group showed poorer temporal resolution at 4 kHz. No relationship was noted between temporal resolution and measures of nonverbal intelligence and language measures. Two subgroups of SLI, one with poor and the other with good temporal resolution, were identified. The SLI subgroup with poor temporal resolution had better frequency discrimination than the SLI subgroup with better temporal resolution. This inverse relationship, not reported before in SLI, can be due to right hemispheric dominance in SLI. However, other possibilities can exist, and it may be speculated that the impaired temporal resolution in a subgroup of SLI is linked more to central neural timing mechanisms than to auditory processing relevant for speech and language development.

**********

Specific language impairment (SLI) has been defined as a persistent developmental limitation in language development in the absence of obvious explanatory factors such as severe hearing loss or severe cognitive dysfunction (Leonard, 1998). Tallal (2000) reviews the evidence for impaired abilities of SLI children in "processing brief, rapidly successive acoustic cues" in nonverbal and verbal stimuli, and characterizes SLI as "a pervasive rate processing constraint that particularly affects the development of normal phonological processing and grammatical morphology, leading to both oral and in many cases written language deficits" (Tallal 2000, p. 150). Leonard (1998) recognizes the difficulty in processing brief or rapidly presented stimuli as an important piece of the SLI puzzle but suggests a number of other pieces to the SLI puzzle, with various forms of constrains in information processing that may be either specific or generalized. Controversy remains as to the explanation for the significant disruption in language development, and this is exaggerated by experimental variations among research groups producing results that conflict with Tallal's influential theory of impaired auditory temporal processing, with some studies failing to show that impaired auditory temporal processing is associated with SLI (Bishop, Carlyon et al., 1999; Helzer et al., 1996; McArthur & Bishop, 2004; Norrelgen et al., 2002). Some authorities have claimed "auditory temporal processing is neither necessary nor sufficient for causing language impairment in children" (Bishop, Carlyon, et al., 1999).

Various reasons for these disparate results have been cited, including differing selection criteria, stimulus design, methodology, demands on attention, and problems related to psychophysical tasks (McArthur & Bishop, 2001; Tallal, 2000, p. 142). Poor discrimination ability, for different frequencies and intensities, is seen as a possible stimulus design-related factor (McArthur & Bishop, 2001) that may result in some SLI subjects performing less well in tasks with brief rapidly presenting stimuli. Tallal's Auditory Repetition Test (ART) used two different tones and, hence, the confounding effect of poor frequency discrimination on temporal resolution could not be ruled out. These psychophysical tasks involved sequencing of sounds and pressing panels and, therefore, effects of task-related complexities on the auditory performance of SLI children could not be ruled out either. The effect of task-related complexity on auditory performance of SLI children was clearly demonstrated by Riddle (1992), and Leonard (1998, p. 143) also stressed this point after a thorough review of the literature.

Effects of individual frequencies per se on auditory temporal processing in SLI have also not been investigated to any great extent. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.