RecruitingClinical trialAlpha Auditory Entrainment for Cognitive Enhancement and Sensory Hypersensitivity in Youth With Developmental DisordersFragile X Syndrome (FXS) is a complex neurodevelopmental disorder caused by a mutation on the X chromosome. Scientists have investigated FXS extensively in both humans and animals. Thus far, phenotypic rescue in animal models has not resulted in treatment breakthroughs in humans, though some important discoveries have been made. Research has shown that individuals with FXS process sounds differently than those in the typical population, and they also show baseline differences in brain activity, including high gamma activity, increased theta activity, and decreased alpha activity. The investigators' central hypothesis is that these alterations in brain activity (specifically alpha and gamma activity) impair the brain's ability to process new information, thereby impeding cognitive functioning and increasing sensory sensitivity. The investigators propose that auditory entrainment, a technique that involves playing special sounds through headphones, will normalize brain activity in individuals with FXS and lead to increased cognitive function and decreased sensory hypersensitivity.