Asynchronies in Auditory and Language Development Obscure Connections to Phonological Deficits in Children.

Purpose: For half a century, psycholinguists have been exploring the idea that developmental language disorders may have their roots in suprathreshold auditory dysfunctions, but results are inconclusive. Typical studies focus on relationships between temporal processing abilities and measures of various language skills at the time of testing, a proximal account. This study expanded that focus by testing three novel hypotheses: (a) Spectral processing impairments may be more responsible for language-learning deficits than temporal processing impairments. (b) Phonological sensitivity is likely the specific language skill most strongly affected by auditory (dys)functions. (c) Poor auditory functioning observed at young ages may wholly or partly recover, reducing the magnitude of relationship between those recovered functions and persistent language skills at older ages. Method: Sixty-six children (31 boys, 35 girls) 7-10 years of age participated: 36 with typical language and 30 with reading or speech disorder; from this sample two subsamples were designated: younger (7-8 years) and older (9-10 years) children. Four auditory measures were obtained of spectral modulation detection (0.5 and 2.0 cycles per octave) and temporal modulation detection (16 and 64 Hz). Four language measures were obtained, two lexicosyntactic and two phonological. Results: Younger children showed deficits in all auditory skills, but most strongly for spectral modulation detection at 0.5 cycles per octave; that measure was the only one for which older children showed deficits. Spectral modulation detection was the auditory function most strongly correlated with a language skill, and that language skill was phonological sensitivity. Conclusions: Early impairments in suprathreshold auditory functions, especially spectral processing, interfere with language acquisition at early stages, especially phonological sensitivity. Although auditory functions can recover to some extent, impairments in language skills persist, indicating that a distal account may more appropriately explain the relationship. [ABSTRACT FROM AUTHOR]