This research on children’s speech in noise and cognitive abilities aimed to determine the age-related trends in speech in noise perception abilities and the relationship between speech in noise perception and cognitive abilities. Monosyllabic distinguishable (consonant-vowel-consonant) words was the most recognisable word category, followed by monosyllabic confusable words (consonant-vowel-consonant), disyllabic non-words (/aCa/) and monosyllabic syllables (/Ca/), demonstrating that phoneme distinctiveness and a reduction in word confusability contribute to their recognition. Older children outperformed younger children on all speech in noise tasks, indicating that there are age-related trends in speech in noise abilities. Children with higher cognitive abilities did not outperform children with lower cognitive abilities on speech in noise tasks, indicating that the ability to hear speech in noise may be an intrinsic feature of the auditory system that matures with age.

Maria Talarico was born on October 11, 1990 to Joe and Nancy Talarico. She has one younger sister. She attended The Ohio State University where she majored in Biomedical Engineering and minored in Exercise Science. She graduated in May 2013 with a B.S. in Biomedical Engineering. She was accepted into the joint graduate program in Biomedical Engineering at North Carolina State University and the University of North Carolina at Chapel Hill. v ACKNOWLEDGMENTS To my family and friends, thank you for your endless support and love during this process without which nothing would be possible. To my committee members, thank you for your support and praise throughout this process. A special thank you to Rob Lynall and Tim Mauntel for all of your help and guidance with every step of the project. vi TABLE OF CONTENTS LIST OF TABLES .

No abstract

Although single-leg squats are a common dynamic balance clinical assessment, little is known about the relationship between parameters that influence squat movement and postural control performance. The objective of this study was to determine the relationships between squat parameters (speed and depth) and postural control under single task and dual task. A total of 30 healthy college students performed single-leg squats under single task and dual task with Stroop. Random-intercepts generalized linear mixed models determined the effect of squat parameters on center of pressure (CoP) parameters. For each 1-cm·s−1 increase in squat speed, sway range (mediolateral: β = −0.03; anteroposterior: β = −0.05) and area (β = −0.25) decreased, whereas sway speed (mediolateral: β = 0.05; anteroposterior: β = 0.29; total: β = 0.29) increased. For each 1-cm increase in squat depth, sway range (mediolateral: β = 0.05; anteroposterior: β = 0.20) and area (β = 0.72) increased, whereas sway speed (anteroposterior: β = −0.14; total: β = −0.14) decreased. Compared with single task, the association between total and anteroposterior sway speed and squat speed was stronger under dual task. Clinicians and researchers should consider monitoring squat speed and depth when assessing dynamic balance during single-leg squats, as these parameters influence postural control, especially under dual task.