Efficacy of Computer-Based Auditory Separation Training in Children with Auditory Processing Disorders

Abstract

Introduction: Difficulty in understanding speech in the presence of background noise is one of the major concerns in children with Auditory Processing Disorders (APD). Auditory separation is the ability of the central auditory system to separate the desired speech signal from the unwanted background noise. Auditory training programs focussing the auditory separation skills have been reported to be an effective remediation option in children with auditory separation deficits. The study aimed at validating a computer-based auditory separation training module developed in Indian-English to be used in children across India irrespective of their mother tongue, using different behavioural and electrophysiological measures. The study also intended to compare the electrophysiological measures in children with APD to their typically developing counterparts. Methods: The study included 30 children (after attrition) in the age range of 8-15 years, out of which 20 were diagnosed as having APD and the remaining 10 were typically developing children (TD group). All the participants had been studying in English medium schools, and were ruled out for any language, reading and cognition deficits using appropriate clinical tools. Ten children with APD were assigned to the experimental APD group, who received training using the computer-based auditory separation training module developed in Indian English and the remaining 10 to the control APD group, who did not receive any training. The outcome measures included five behavioural APD tests, which included Speech Perception in Noise test (SPIN), Gap Detection Test (GDT), Duration Pattern Test (DPT), Dichotic CV test (DCV) and Revised Auditory Memory and Sequencing Test (RAMST), electrophysiological measures, which included Auditory Late Latency Responses (ALLR) elicited for speech stimuli (/da/ syllable in quiet and noise (at 0 dB SNR). The outcomes measures were administered thrice in the experimental APD group (before and after training, and 1 month after cessation of the training) and twice in the control APD group (with an gap of 3-4 weeks, with no training imparted during the gap). The tests were administered only once in the TD group. Results: Study revealed a significant improvement in the scores of SPIN, GDT, DPT, auditory memory and the double correct scores of DCV after training in the experimental APD group; unlike the control APD group. Increased amplitudes and early latencies were observed of the ALLR components (N2 peak) in children with APD compared to the TD group. Significant reduction in the amplitudes of the ALLR components (P1 and N2) was observed after training in the experimental APD group. The changes were observed for ALLR recorded in quiet as well as in noise conditions. A negative correlation was observed between changes in the N2 latencies and the double correct scores of dichotic CV test and auditory memory scores after training. Conclusion: The computer-based auditory separation training module developed in Indian English was successful in fetching improvements in the auditory separation skills as well as the related auditory processing skills in children with APD. The changes in the behavioural measures were further supported by the changes in the electrophysiological measures. Also, the changes observed in the ALLR measures in children with APD after the training, followed the maturational pattern and tended to be approaching closer towards that of the typically developing children. Considering the improvement observed in the behavioural and electrophysiological measures, the computer-based auditory separation training module in Indian English would be a great addition to the rehabilitation inventory for children with APD in India.