Medicine and Health Sciences Commons^™

Effects Of Hearing Aid Amplification On Robust Neural Coding Of Speech, Jonathan Daniel Boley

Open Access Dissertations

Hearing aids are able to restore some hearing abilities for people with auditory impairments, but background noise remains a significant problem. Unfortunately, we know very little about how speech is encoded in the auditory system, particularly in impaired systems with prosthetic amplifiers. There is growing evidence that relative timing in the neural signals (known as spatiotemporal coding) is important for speech perception, but there is little research that relates spatiotemporal coding and hearing aid amplification.

This research uses a combination of computational modeling and physiological experiments to characterize how hearing aids affect vowel coding in noise at the level of …

Developing A Drug Delivery System For Treatment Of Vocal Fold Scarring, Aaron Michael Kosinski

Open Access Dissertations

Vocal fold scarring is an affliction that results in the formation of a disorganized and stiff extracellular matrix (ECM) with abnormal ECM component densities & structures including a significant increase in collagen deposition. It is caused by improper healing post injury and results in profound changes in the biomechanical properties of the vocal folds impairing their ability to generate a normal mucosal wave during phonation.

Finding an effective treatment for vocal fold scarring has been elusive. Currently, treatments seek temporary solutions that correct glottal incompetence and reduce stiffness caused by the scar through the augmentation of the vocal folds using …

Predicting Language Impairment Status: A Risk Factor Model, Johanna Maria Rudolph

Open Access Dissertations

The etiology of specific language impairment (SLI) is multifactorial. Research has shown that genetic, environmental, and developmental factors may influence the course of its development. Because many of these factors are present even before a child is born, it is possible that a child's risk of developing the disorder can be identified long before grammatical deficits are observed. The goal of this study was to develop and validate a screening tool to discriminate between children with SLI and typically developing (TD) children using risk factor information including gender, family history of communication or reading disorders, socioeconomic status, maternal and paternal …

Neural Encoding Of Complex Signals In The Healthy And Impaired Auditory Systems, Saradha Ananthakrishnan

Open Access Dissertations

Individuals with sensorineural hearing loss (SNHL) typically experience difficulty in understanding speech. Our current knowledge of deficits in speech perception and encoding consequent to SNHL is restricted to psychophysical studies in humans and single-unit experiments in animals. However, the nature of degradation in neural encoding of speech following hearing impairment in humans has not been extensively researched. The objective of this dissertation is to provide a systematic evaluation of neurobiological signature of hearing loss at the subcortical level using an objective electrophysiological non-invasive neural index, the frequency following response (FFR). Subcortical neural encoding of speech signals is explored by quantifying …

Age-Related Changes To The Production Of Linguistic Prosody, Daniel Richard Barnes

Open Access Theses

The production of speech prosody (the rhythm, pausing, and intonation associated with natural speech) is critical to effective communication. The current study investigated the impact of age-related changes to physiology and cognition in relation to the production of two types of linguistic prosody: lexical stress and the disambiguation of syntactically ambiguous utterances. Analyses of the acoustic correlates of stress: speech intensity (or sound-pressure level; SPL), fundamental frequency (F0), key word/phrase duration, and pause duration revealed that both young and older adults effectively use these acoustic features to signal linguistic prosody, although the relative weighting of cues differed by group. Differences …

Preschool Language And Phonological Proficiencies In Predicting Stuttering Recovery Or Persistence, Caroline E. Spencer

Open Access Theses

The purpose of this study was to investigate the relationship between expressive and receptive language, phonological, and verbal working memory proficiencies in the preschool years and eventual recovery from or persistence in stuttering. Participants included 40 children who stutter (CWS). At ages 3-5 years, participants were administered the Test of Auditory Comprehension of Language, 3rd edition (TACL-3), the Structured Photographic Expressive Language Test, 3rd edition (SPELT-3), Bankson-Bernthal Test of Phonology--Consonant Inventory subtest (BBTOP--CI), Test of Auditory Perceptual Skills--Revised (TAPS--R) auditory number memory and auditory word memory subtests, and the Dollaghan & Campbell Nonword Repetition Test (NRT). Stuttering behaviors were tracked …