This dissertation is the documentation for a Doctoral research program undertaken at the Industrial Research Institute of the Swinburne University of Technology (IRIS), in collaboration with the School of Biophysical Sciences and Electrical Engineering (BSEE), between the years of 2000 and 2004. The objective of the research work that was undertaken was to study the auditory brainstem response (ABR) characteristics of people with Parkinson�s Disease (PD) to determine whether or not these characteristics could form the basis of a tool for determining the presence of PD; the performance of medication, and disease progression. Prior to the commencement of this research, the gold-standard for PD diagnostics was considered to be autopsy, and the only tools available for assessment of living patients were fluoro-deoxyglucose (FDG) / fluoroDopa (FDopa)-based positron emission tomography (PET) or conventional (subjective) clinical testing. The use of PET was costly and impractical for monitoring disease progression. Clinical testing approaches, on the other hand, had a degree of subjectivity, leading to potential misdiagnoses with inadequately trained clinicians. It was therefore postulated that a low-cost technique based on conventional ABR testing equipment, which was readily available within the medical environment, could provide considerable benefits. In order to be useful as a tool, ABR would ultimately need to identify uniquely the presence of PD from other potential disorders, most notably multiple system atrophy (MSA) which was sometimes confused with PD. At the time this research was conducted, the prevailing method of differentiating PD from MSA was based upon magnetic resonance imaging (MRI). This research was only concerned with the first stage of such a research process � that is, determining whether the ABR of PD patients was fundamentally different to that of a control group. In undertaking the investigation, a significant component of the research involved drawing together research literature from a large number of sources in order to present a case that could present a reasonable research path for experimentation. The next stage of the research involved developing an experimentation program that could be used to compare the ABR characteristics of people with PD against a control group and, further, to compare the ABR characteristics of PD participants against their level of impairment, as measured on a conventional mobility test. In summary, the outcomes of the experimental process that was undertaken, and the statistical analysis of the outcomes, suggested that: (1) People with mild manifestations of PD, who were in an unmedicated state, had marked abnormalities in the amplitude of Wave III of their ABR waveform. (2) The amplitude of Wave III of the ABR waveform was sensitive to variations in PD medication levels. (3) The amplitude of Wave V of the ABR waveform was, to a lesser extent than Wave III, affected by the presence of PD and medication levels. (4) The latencies of Waves III and V of the ABR waveforms did not appear to be affected by the presence of PD or by variations in medication levels. This thesis presents the results of the experimental study, together with a statistical analysis of the significance of the outcomes and an evaluation of the limitations of the work that was carried out. The recommendations arising from the research outcomes suggest ways for extending the work that has been completed in this program.

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (M. Communication Pathology)--University of Pretoria, 2008. / Summary in English and Afrikaans. Includes bibliographical references.

No description available.

No description available.

The frequency following potential (FFP) is an auditory evoked response which crudely replicates the waveform of the stimulus. The origins of this far-field potential have been localized to the cochlea and specific auditory nuclei. The initiation site of the FFP along the cochlear partition has been thought to be dependent upon stimulus sound pressure level. Low stimulus levels elicit FFP from the apical turn of the cochlea, while moderate and high stimulus levels may elicit FFP from a large segment of the partition, including the basal turn. Simultaneous masking studies have contributed to the knowledge of this potential, but results from these studies may be confounded by interference from bioelectric potentials generated by distortion products from the masking noise. This investigation used non-simultaneous masking tones set at the subject's pulsation threshold level (PTL). This psychophysical method provides a representation of the frequency-resolving properties of the auditory periphery in a repeated gap masking paradigm. Patterns of the relative masking effect of each masking tone were plotted and compared for several probe levels and in the presence or absence of a continuous, high-pass masking noise. Tuning patterns derived in high-pass making noise effectively represented apical turn FFP. Those patterns without masking noise represented whole-cochlea FFP. The results of this study demonstrarted tuning patterns that reflected diminished FFP amplitudes in the primary 500 Hz region as well as in an extended secondary range of 800 to 2000 Hz, depending on the stimulus-masking parameters. Tuning patterns in high-pass masking noise were consistently flatter in the primary and secondary regions than for the tuning patterns without masking noise. The secondary regions of the tuning patterns extended above 2000 Hz for the patterns obtained without high-pass masking. Tuning patterns were consistently broader for the high stimulus level than for the moderate stimulus level. The multiple cochlear initiation sites for the FFP preclude its use as an audiological tool for the assessment of low-frequency hearing. However, the potential is suggested as a method to assess whole-cochlear response for the difficult-to-test patients with suspected profound hearing loss.

Thesis (Au. D.)--Missouri State University, 2008. / "May 2008." Includes bibliographical references (leaves 49-53). Also available online.

Thesis (M. Aud.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.

Thesis--University of Jyväskylä, 1997. / Added t.p. with thesis statement inserted.

Thesis (M. Sc.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 88-91).