title: The relation between working memory capacity and auditory lateralization in children with auditory processing disorders.
abstract: OBJECTIVE
  Auditory processing disorder (APD) describes a complex and heterogeneous disorder characterized by poor speech perception, especially in noisy environments. APD may be responsible for a range of sensory processing deficits associated with learning difficulties. There is no general consensus about the nature of APD and how the disorder should be assessed or managed. This study assessed the effect of cognition abilities (working memory capacity) on sound lateralization in children with auditory processing disorders, in order to determine how "auditory cognition" interacts with APD.
  
  
  METHODS
  The participants in this cross-sectional comparative study were 20 typically developing and 17 children with a diagnosed auditory processing disorder (9-11 years old). Sound lateralization abilities investigated using inter-aural time (ITD) differences and inter-aural intensity (IID) differences with two stimuli (high pass and low pass noise) in nine perceived positions. Working memory capacity was evaluated using the non-word repetition, and forward and backward digits span tasks. Linear regression was employed to measure the degree of association between working memory capacity and localization tests between the two groups.
  
  
  RESULTS
  Children in the APD group had consistently lower scores than typically developing subjects in lateralization and working memory capacity measures. The results showed working memory capacity had significantly negative correlation with ITD errors especially with high pass noise stimulus but not with IID errors in APD children.
  
  
  CONCLUSIONS
  The study highlights the impact of working memory capacity on auditory lateralization. The finding of this research indicates that the extent to which working memory influences auditory processing depend on the type of auditory processing and the nature of stimulus/listening situation.
authors.affiliation: Department of Otolaryngology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Abdollah
authors.initials: A
authors.lastname: Moossavi
authors.affiliation: Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Electronic address: saeidehmehrkian@yahoo.com.
authors.forename: Saiedeh
authors.initials: S
authors.lastname: Mehrkian
authors.affiliation: Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
authors.forename: Yones
authors.initials: Y
authors.lastname: Lotfi
authors.affiliation: Department of Social Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Soghrat
authors.initials: S
authors.lastname: Faghihzadeh
authors.affiliation: Department of Engineering, Shahed University, Tehran, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: sajedi
mesh_terms: D000161:Acoustic Stimulation; D001308:Auditory Perceptual Disorders / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D009622:Noise; D013067:Speech Perception
keywords: Auditory lateralization; Auditory processing; Working memory; Working memory capacity