Title

The ISI Critical Value in Backward Masking Testing

Presentation Type

Poster

Abstract

Backward Masking (BM) has been studied both as a psychoacoustic phenomenon and as a potential diagnostic indicator of auditory processing. BM refers to the process of intentionally raising the sensory threshold for a target stimulus by means of an interfering stimulus after the target, usually an auditory masker. Backward masking has demonstrated high significance for the study of Auditory Processing Disorders (APD), including many learning impairments. A comprehensive study compared the BM thresholds of a group of children with language impairment with a control group (Marler et al., 2003) and found significant differences between the groups. Gehr and Sommers (1999) found that in an older age group with normal pure-tone auditory thresholds, BM thresholds were significantly higher. In BM assessment, the subject typically responds to a brief tonal signal followed by an Inter-Stimulus Interval (ISI) of silence and then by a noise masker. This study used unique instrumentation that obtained the adaptive ISI to maintain threshold. In all previous studies the ISI is varied by the experimenter and an adaptive auditory threshold is obtained at each ISI. This study employed a threshold tracking procedure where the subject did not alter the intensity of the tonal stimulus, but instead, the subject tracking changed the length of the ISI.

Category

Life Sciences

This document is currently not available here.

Share

COinS
 
Apr 15th, 3:00 PM Apr 15th, 4:00 PM

The ISI Critical Value in Backward Masking Testing

Backward Masking (BM) has been studied both as a psychoacoustic phenomenon and as a potential diagnostic indicator of auditory processing. BM refers to the process of intentionally raising the sensory threshold for a target stimulus by means of an interfering stimulus after the target, usually an auditory masker. Backward masking has demonstrated high significance for the study of Auditory Processing Disorders (APD), including many learning impairments. A comprehensive study compared the BM thresholds of a group of children with language impairment with a control group (Marler et al., 2003) and found significant differences between the groups. Gehr and Sommers (1999) found that in an older age group with normal pure-tone auditory thresholds, BM thresholds were significantly higher. In BM assessment, the subject typically responds to a brief tonal signal followed by an Inter-Stimulus Interval (ISI) of silence and then by a noise masker. This study used unique instrumentation that obtained the adaptive ISI to maintain threshold. In all previous studies the ISI is varied by the experimenter and an adaptive auditory threshold is obtained at each ISI. This study employed a threshold tracking procedure where the subject did not alter the intensity of the tonal stimulus, but instead, the subject tracking changed the length of the ISI.