title: Evidence for a general auditory processing deficit in developmental dyslexia from a discrimination paradigm using speech versus nonspeech sounds matched in complexity.
abstract: OBJECTIVE
  It is unknown whether phonological deficits are the primary cause of developmental dyslexia or whether they represent a secondary symptom resulting from impairments in processing basic acoustic parameters of speech. This might be due, in part, to methodological difficulties. Our aim was to overcome two of these difficulties: the comparability of stimulus material and task in speech versus nonspeech conditions.
  
  
  METHODS
  In this study, the authors (a) assessed auditory processing of German vowel center stimuli, spectrally rotated versions of these stimuli, and bands of formants; (b) used the same task for linguistic and nonlinguistic conditions; and (c) varied systematically temporal and spectral parameters inherent in the German vowel system. Forty-two adolescents and adults with and without reading disabilities participated.
  
  
  RESULTS
  Group differences were found for all linguistic and nonlinguistic conditions for both temporal and spectral parameters. Auditory deficits were identified in most but not all participants with dyslexia. These deficits were not restricted to speech stimuli-they were also found for nonspeech stimuli with equal and lower complexity compared with the vowel stimuli. Temporal deficits were not observed in isolation.
  
  
  CONCLUSIONS
  These results support the existence of a general auditory processing impairment in developmental dyslexia.
authors.forename: Corinna A
authors.initials: CA
authors.lastname: Christmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Lachmann
authors.forename: Claudia
authors.initials: C
authors.lastname: Steinbrink
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001308:Auditory Perceptual Disorders / Q000503:physiopathology / Q000523:psychology*; D016022:Case-Control Studies; D004410:Dyslexia / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D005858:Germany; D006801:Humans; D007802:Language; D008297:Male; D010700:Phonetics; D011578:Psycholinguistics; D011932:Reading; D013060:Speech / Q000502:physiology; D013647:Task Performance and Analysis; D055815:Young Adult