Vowel perception primarily depends on the overall shape of the speech spectrum, which is imposed by the positions of the primary speech articulators. Voiced vowels also have a harmonic fine structure due to the activity of the vocal folds, and these harmonics give rise to synchronized activity in the brainstem. This synchronous firing may be useful for speech perception in noise and speaker discrimination, although it is unknown if the synchronized neural response to the harmonic increases perceptual audibility of the harmonic. The focus of the current study was to examine the relationship between the audibility of harmonics and the brainstem response to harmonics. The individual harmonics were found to be encoded in the brainstem, determined using brainstem frequency-following response recording, and the individual harmonics were audible to the individual, as determined using the pulsation threshold technique; however there was minimal relationship between the frequency-following response and perception of harmonics.

No description available.

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Any phonological theory needs to encompass an account of acquisition and any account of acquisition must take its place within a general theory of phonology. This thesis aims to ascribe phonological significance to speech perception in infancy, a move impossible unless phonology is defined, as it is here, from both a psycholinguistic and a formal viewpoint as a dedicated pattern-recognition system. Extant results from infant studies are reviewed and aligned with current phonological theory. In particular, such theory characterises phonology as bi-modular, so the acquisition of individual melodic and prosodic modules and their subsequent orientation with respect to one another must constitute three different developmental tasks. This delivers a relatively simple account of the mapping between psychoacoustics and phonology. Perception and pre-existing theories of segmental complexity are related using an original experiment into the perception of vowel-height contrast in Catalan. If infant perception has phonological import, then disparate phonetic reflexes which are predicted as phonologically identical should show parallels in acquisition. General theory argues that the same abstract melodic objects underlie both laryngeal contrasts in stops and lexical tonal contrasts. Earlier studies show that language-specific attunement to stop contrasts has taken place by the age of six months. New tests are now reported, using children of the same age, which demonstrate that infants acquiring Yorùbá, a language which has a three-way contrast for tone, attend more closely to pitch changes within the minimal domain word than do English controls. Further, they only attend to those pitch changes that possess phonological import within that domain in the steady-state language. In this their perception exactly parallels that displayed by adult speakers. Apparent anomalies in the results of these tests are shown to be closely parallelled by phonological asymmetries in the tonology of Yorùbá.

Thesis (Ph. D.)--University of Oregon, 2002. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 127-139). Also available for download via the World Wide Web; free to University of Oregon users. Address: http://wwwlib.umi.com/cr/uoregon/fullcit?p3045096.

published_or_final_version / Speech and Hearing Sciences / Doctoral / Doctor of Philosophy

The World Wide Web provides the capability of delivering multi-media presentations to a wide audience. This thesis details the design and development of the site Psychoacoustical demonstrations and experiments at McGill University: it discusses site organization, selection of materials and development methods. In order to evaluate the utility of the site, site usage data, feedback from readers and data from experiments are analyzed and discussed. The thesis examines the success of the site in attracting a wide audience and holding its attention, as course material, in gathering data from psychoacoustical experiments, and in obtaining feedback from readers. Suggestions for future sites of this type are included. / The test of the thesis should be read in conjunction with experiencing the World Wide Web site at http://www.music.mcgill.ca/auditory/Auditory.html.

The purpose of this research work is to investigate the relationship between humidity and tone in musical instruments. A basic hypothesis that motivates this work is that normal seasonal variations in relative humidity are thought to alter the tone of instruments constructed from wood. These changes in tone are believed to be due to changes in the dimensions and material properties of an instrument that are a result of wooden components absorbing and adsorbing water in equilibrium with their ambient environmental conditions. To investigate this hypothesis an experiment was conducted with a guitar acclimatized at different relative humidity levels. Sample sounds recorded at each humidity level were then evaluated by the test subjects using a three alternative forced choice listening test paradigm. Subjects were readily able to distinguish sounds recorded at different humidity levels, supporting the claim that changes in ambient humidity can create perceptible differences in instrument tone. A finite difference model was then developed to produce simulated sounds as a function of moisture content (MC being the weight percentage of a piece of wood that is water). The model was validated and further listening tests were conducted to determine the perceptual limit of MC differences. The just-noticeable difference value for MC change was established to be 0.7% MC difference. To be considered imperceptibly stable with respect to tone, materials used to replace traditional soundboard woods would need to have less variability than the equivalent material property changes due to this 0.7% MC difference. Testing of an acetylated plate in terms of its vibration and material properties followed. An increase in both stiffness and density was noted, yet even after modification the vibration properties of the plate were observed to remain within an acceptable range of material properties typical of soundboard grade woods. Instrument builders would likely welcome this new material, as long as its properties can be shown to not vary significantly from traditional choices. A second component of this thesis concerns the application of wavelets in musical analysis. Psychoacoustical signal parameters (PSPs) are a tool used to quantify aspects of sounds, such as brightness or percussiveness. These PSPs are often calculated using the Fast Fourier Transform (FFT), an algorithm that has certain limitations. To address the deficiencies of the FFT a wavelet transform was em- ployed and conventional PSPs were reformulated in the wavelet domain to improve their accuracy. Tonal differences due to changes in MC were shown to be well suited to analysis by wavelet PSPs where improved sensitivity was observed in comparison to the conventional methods. Finally, an acoustical study of the development of the piano from the clavichord to the modern grand piano was conducted. An improved bass response and the presence of more energy in the upper partials, particularly in these bass notes, were concluded to be due to an increase in soundboard area, the introduction of longer string scale lengths, and the use of wound strings for bass notes.

Thesis (Ph. D.)--University of Hong Kong, 2005.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 105-107).