Part 2: Training

The experimental group was trained for formal localization skills in a course of 9 sessions using disyllabic nonwords with different ITD ENV values (12). The participants were asked to respond by showing the direction of the sound in the right or left side (24). Each ITD was frequently presented to the individuals so that they could identify it properly. The ITD ENV training program began for each participant at 20 milliseconds above the ITD ENV threshold that was obtained in the evaluation part so that localization would be attainable for the participants (31). Each training step was delivered to the individual 10 times. If the presented ITD could correctly localize the source, it would then be reduced in 10 millisecond steps. In the case of no improvement in new ITD ENV, the previous ITD ENV was practiced again. To investigate the effectiveness of the training program, ITD ENV threshold and spatial WRS in noise was obtained post training.

This study was approved by the ethics committee of the University of Social Welfare and Rehabilitation Sciences (code IR.USWR.REC.1394.3).