Design and Implementation of a Tactile Stimulation Device to Increase Auditory Discrimination

Reading is a complex process that requires various simultaneous brain processes. One of the most common types of reading disorders is developmental dyslexia, and one of the objectives of speech therapy sessions for children with developmental dyslexia is to increase their auditory discrimination. One of the most commonly used Auditory Discrimination Tests (ADTs) is Wepman's  Auditory Discrimination Test (WADT). It includes minimal pair words categorized by characteristics of vowels and consonants. The goal of this research is to design and implement a tactile stimulation device based on Wepman's test to increase auditory discrimination in children with developmental dyslexia in therapy sessions, so that while playing each word for the children, vibrational cues are presented to their left palm and fingers. The vibrational cues provided by 23 vibration motors can notify the child of the difference or similarity between the words. First, the device was evaluated by being applied on six female participants aged 6 to 8 with no hearing disabilities and no developmental dyslexia. Scores obtained from the healthy children showed that they can perceive the tactile function of the device. Then, function of the device was tested on 8-year-old twin girls with developmental dyslexia. The test was conducted as a controlled experiment. One of the twins participated in speech therapy treatment, while the other practiced with the device. During the study, three sessions were allocated to determine the baseline of auditory discrimination, three sessions to the intervention, and two sessions (the first, one week and the second, three weeks after the intervention sessions) to determine the children's auditory discrimination (follow-up). The analysis of trend variations and changes in mean showed that both the speech therapy and the intervention based on practicing with the device were effective in increasing children's auditory discrimination (Percentage of Non-overlapping Data = 100%). The results were stable three weeks after the intervention sessions. Therefore, using the device in speech therapy sessions can be useful and effective in improving auditory discrimination.