Artikel
Development of auditory localization abilities in healthy children aged six to twelve years: estimations of normative data ranges for Minimum Audible Angle (MAA)
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Veröffentlicht: | 8. Juli 2008 |
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Introduction: The evaluation of spatial hearing as a central auditory skill can be an important diagnostic hint in identifying children with central auditory processing disorders (CAPD). To improve the quantification of that ability, the present study aimed at establishing normative data for Minimum Audible Angles (MAA) in children, which haven't been available so far.
Methods: Short, high- or low-frequency broadband noise bursts were presented to 64 normally hearing children (age range 6 to 12 years, median age 8 years 8 months) from seven reference directions situated in the frontal azimuthal hemifield. From each group of three subsequently presented signals (twice from reference direction, once from deviant direction, minimal angular separation of 4°), the hearing event perceived as spatially differing from the others had to be recognized. Minimum Audible Angles for high- and low-frequency signals were determined for seven reference directions (0°, ±30°, ±60°, ±90°) using an adaptive procedure.
Results: MAA of eight- to twelve-year-olds were significantly smaller than those of children aged six and seven years for all seven reference directions (p<.05, robust rank order), for five of them highly significantly (p<.001). Minimum Audible Angles increased towards peripheral directions (p<.001, Friedman RM ANOVA on ranks). A significant frequency dependance could be observed in a more clearly way in older children aged eight to twelve years (p<.05, Wilcoxon matched pairs).
Conclusions: Spatial hearing differentiates with age and is, moreover, dependent on signal laterality. However, no systematic influence of signal frequency could be observed. The data provided until now might be used as a basis for investigations in children with CAPD.