Binaural Masking Release in Children With Down Syndrome

Abstract

The binaural advantages afforded to typically developing children, such as enhanced hearing sensitivity in noise, were not as robust for children with Down syndrome in this study. Children with Down syndrome experienced less binaural benefit than typically developing peers for some stimuli, suggesting that they could require more favorable signal-to-noise ratios to achieve optimal performance in some adverse listening conditions. The reduced release from masking observed for children with Down syndrome could represent a delay in ability rather than a deficit that persists into adulthood. This could have implications for the planning of interventions for individuals with Down syndrome.

Masking Level Difference: Performance of School Children Aged 7–12 Years

“…A study analyzing children with Down syndrome (compared with children with typical development) showed a significant difference in the performance of both groups. Such findings suggest a delay in the maturation of this ability in children with Down syndrome, but this difference disappears when they become adults [5].…”

“…When the phase is the same, the threshold is high because stimuli and noise seem to be in the same source. But in the antiphasic condition, the stimuli are reversed relative to that of the noise, and the threshold is low, seeming to be in a different source [5]. So, the antiphasic condition is known to provide more auditory cues compared to the homophase condition, and a lower threshold for the antiphasic condition demonstrates an increase in detectability [14].…”

“…Sound source localization depends on the analysis and comparison of the stimuli reaching the right and left ears. In addition, binaural hearing im-proves auditory sensitivity, that is, more accurate localization of auditory signals, and oral comprehension in noisy environments when sound sources are spatially separated [4,5].…”

“…It can be performed using different parameters of administration-for example, noise and pure tone in the same phase (SoNo), noise in reversed phase in one ear and pure tone in phase in both ears (SoNπ), or pure tone in reversed phase in one ear and noise in phase in both ears (SπNo) [12]. Besides different administration protocols, some versions are available with recorded materials or coupled to audiometers [5,10,15,16].…”

“…Despite the importance of the MLD test in the evaluation battery and its growing clinical use, few studies have been conducted with Brazilian adult [17] and pediatric populations [10,18]. Previous studies have shown various results regarding the MLD scores of school-aged children throughout many countries [5,10]. No normality standard for Brazilian schoolaged children has been defined yet.…”