Vowel normalisation: Time-domain processing of the internal dynamics of speech

Human listeners can identify vowels regardless of speaker size, although the sound waves for an adult and a child speaking the ’same’ vowel would differ enormously. The differences are mainly due to the differences in vocal tract length (VTL) and glottal pulse rate (GPR) which are both related to body size. Automatic speech recognition machines are notoriously bad at understanding children if they have been trained on the speech of an adult. In this paper, we propose that the auditory system adapts its analysis of speech sounds, dynamically and automatically to the GPR and VTL of the speaker on a syllable-to-syllable basis. We illustrate how this rapid adaptation might be performed with the aid of a computational version of the auditory image model, and we propose that an auditory preprocessor of this form would improve the robustness of speech recognisers.

Exploiting Chinese character models to improve speech recognition performance

The Chinese language is based on characters which are syllabic in nature. Since languages have syllabotactic rules which govern the construction of syllables and their allowed sequences, Chinese character sequence models can be used as a first level approximation of allowed syllable sequences. N-gram character sequence models were trained on 4.3 billion characters. Characters are used as a first level recognition unit with multiple pronunciations per character. For comparison the CU-HTK Mandarin word based system was used to recognize words which were then converted to character sequences. The character only system error rates for one best recognition were slightly worse than word based character recognition. However combining the two systems using log-linear combination gives better results than either system separately. An equally weighted combination gave consistent CER gains of 0.1-0.2% absolute over the word based standard system. Copyright © 2009 ISCA.

Product aesthetics: representing designer intent and consumer response

This thesis reports on the development of a conceptual framework for product aesthetics. By adopting the theoretical perspective that products are a medium of communication between designers and consumers, the nature of consumer response and designer intent is explored. By integrating a range of disparate literature within a single coherent framework, the varieties of consumer response to product visual form are illustrated. To investigate the ways in which designers intend to evoke these responses, a qualitative research study was undertaken. This primarily involved interviews with industrial designers and consumer investigators. Analysis of these interviews led to the development of a conceptual framework for designer intent which both mirrors, and integrates with, that produced for consumer response. By representing processes beyond design that are influential in determining product form, a broader contextual framework is presented within which product aesthetics is situated. In concluding the thesis, applications for this framework are discussed and future research directions are proposed.