The audiology profession discontinued the master's degree in 2012, consequently - no master's thesis since then in the U.S. Most Doctor of Audiology (Au.D.) programs do not require a research component for graduation as it is a professional, not a graduate, degree. However, a few require a 'Capstone' research project; but they may not be published. You could look at the American Auditory Society's journal and AAA's Journal of the American Academy of Audiology. Another source would be to look for Ph.D.'s dissertations in areas like auditory neurophysiology, etc. They would typically come from Departments of Communication Sciences and Disorders.