In this thesis, the basic theory describing wave propagation in tubes of varying cross-section is outlined, together with a review of how the time domain technique of APR can be used to measure the input impulse response of a tubular object, such as the vocal tract, from which the bore profile can be calculated using the layer peeling algorithm. Experimental measurements of the human vocal tract during the phonation (imitation of) for five non-nasalised vowels [a, e, i, o, u] are presented, using recent enhancements to the APR technique (MLS excitation signals and virtual DC tube method) for a single subject, together with optimisation of the APR technique for vocal tract measurement and its application in a group study using adults and children. To validate the results obtained using the APR technique, a comparative study with an accepted ‘gold standard’ imaging technique (MRI) is presented, using the same subject, a voice professional, in both studies. The results from this study show reasonable overall agreement between the APR and MRI data, with the limited resolution of the acoustic technique tending to broaden features and underestimate cross sectional areas, particularly in the region of the pharynx and glottis. Protocols and supplementary documentation required by scientific, clinical and ethical review bodies for the use of human volunteers in research trials are documented. From this study a data corpus of vocal tract measurements is gathered, using the techniques of APR and MRI, in adult males, adult females and children. In concluding, limitations of the APR technique for vocal tract measurement are discussed and potential improvements are proposed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:651743 |
| Date | January 2005 |
| Creators | Gray, Calum David |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13947 |
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