Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 106-113).

The current study investigates the effect of auditory and visual speech information and orthographic information on second/foreign language (L2) acquisition. To test this, native speakers of Turkish (a language with a transparent orthography) and native speakers of Australian English (a language with an opaque orthography) were exposed to Spanish (transparent orthography) and Irish (opaque orthography) legal non-word items in four experimental conditions: auditory-only, auditory-visual, auditory-orthographic, and auditory-visual-orthographic. On each trial, Turkish and Australian English speakers were asked to produce each Spanish and Irish legal non-words. In terms of phoneme errors it was found that Turkish participants generally made less errors in Spanish than their Australian counterparts, and visual speech information generally facilitated performance. Orthographic information had an overriding effect such that there was no visual advantage once it was provided. In the orthographic conditions, Turkish speakers performed better than their Australian English counterparts with Spanish items and worse with Irish terms. In terms of native speakers' ratings of participants' productions, it was found that orthographic input improved accent. Overall the results confirm findings that visual information enhances speech production in L2 and additionally show the facilitative effects of orthographic input in L2 acquisition as a function of orthographic depth. Inter-rater reliability measures revealed that the native speaker rating procedure may be prone to individual and socio-cultural influences that may stem from internal criteria for native accents. This suggests that native speaker ratings should be treated with caution. / Master of Arts (Hons)

Objectives: The purpose of this study was to examine the effects of degree and configuration of hearing loss on the use of, and benefit from, information in amplified high- and low-frequency speech presented in background noise. Design: Sixty-two adults with a wide range of high- and low-frequency sensorineural hearing loss (5 to 115+ dB HL) participated in the study. To examine the contribution of speech information in different frequency regions, speech understanding in noise was assessed in multiple low- and high-pass filter conditions, as well as a band-pass (713 to 3534 Hz) and wideband (143 to 8976 Hz) condition. To increase audibility over a wide frequency range, speech and noise were amplified based on each individual's hearing loss. A stepwise multiple linear regression approach was used to examine the contribution of several factors to (1) absolute performance in each filter condition and (2) the change in performance with the addition of amplified high- and low-frequency speech components. Results: Results from the regression analysis showed that degree of hearing loss was the strongest predictor of absolute performance for low- and high-pass filtered speech materials. In addition, configuration of hearing loss affected both absolute performance for severely low-pass filtered speech and benefit from extending high-frequency (3534 to 8976 Hz) bandwidth. Specifically, individuals with steeply sloping high-frequency losses made better use of low-pass filtered speech information than individuals with similar low-frequency thresholds but less high-frequency loss. In contrast, given similar high-frequency thresholds, individuals with flat hearing losses received more benefit from extending high-frequency bandwidth than individuals with more sloping losses. Conclusions: Consistent with previous work, benefit from speech information in a given frequency region generally decreases as degree of hearing loss in that frequency region increases. However, given a similar degree of loss, the configuration of hearing loss also affects the ability to use speech information in different frequency regions. Except for individuals with steeply sloping high-frequency losses, providing high-frequency amplification (3534 to 8976 Hz) had either a beneficial effect on, or did not significantly degrade, speech understanding. These findings highlight the importance of extended high-frequency amplification for listeners with a wide range of high-frequency hearing losses, when seeking to maximize intelligibility.