An acoustic, aerodynamic and perceptual investigation of word-initial denasalization in Korean

Korean nasals /m/ and /n/ are generally considered by Korean phoneticians to be hardly different from the corresponding English sounds, but those in word-initial position are often perceived as plosives by native speakers of English. This had been noted by only a few previous observers, and investigated on a very limited scale. In this study, various experimental methods were employed in systematic analyses of the production and acoustic form of word-initial /m/ and /n/ from fluent connected speech collected from a relatively large number of informants, and corresponding perception tests were conducted with groups of Korean and English listeners. Auditory and spectrographic analyses confirmed that the segments were commonly “denasalized”. They display characteristics widely different from those of sonorant nasals, lacking the nasal formants commonly seen in spectrograms; in most cases they were more similar to voiced plosives, many tokens even showing plosive-like release bursts. Spectral analyses confirmed that denasalized nasals are significantly different from sonorant nasals throughout the whole frequency range but remain somewhat different from voiced plosives in the low and high frequency regions. Aerodynamic and accelerometer studies, which examined the consonants in CV combinations, indicated that the denasalized sounds are evidently produced with a pattern of velopharyngeal control which is different from those of sonorant nasals or of plosives. Perception tests showed overwhelmingly that the word-initial denasalized sounds are categorized as nasals by Korean listeners but as plosives by English listeners. When real voiced plosive tokens from another context are artificially moved to word-initial position, Koreans perceive these too as nasals, while English listeners’ responses are not sensitive to the context. The study shows that denasalization needs to be acknowledged as a major regular feature of spoken Korean, even though it has been largely ignored up to now. Directions for further research are outlined

Models and analysis of vocal emissions for biomedical applications

This book of Proceedings collects the papers presented at the 3rd International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2003, held 10-12 December 2003, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

Cues to Vowels in the Aperiodic Phase of English Plosive Onsets

This thesis addresses the problem of vowel recognition in coarticulatory theory and phonology by assessing how early vowel quality can be recognised from English onset plosives realised with aspiration. Particular attention is paid to aspects of production and perception timing. A gating experiment was used to assess how reliably listeners can recognise English monophthongs. The treatment of coarticulation distinguishes between phonetic and phonological aspects of production and perception, with a clear demarcation between these levels of representation. The results are interpreted through the lens of prosodic phonology, as this framework constrains the grammar more optimally than segmental-phonemic ones and better exemplifies listeners’ sensitivity to the distribution of FPD. Velar and bilabial onsets give rise to significantly more correct responses than alveolars, which require more precise articulations. High vowels are recognised more reliably than low ones. This result is due to their intrinsically shorter duration, making high vowels less variable through time. This perceptual link is proportionate to the total amount of variation in vowel inherent spectral change (VISC), which corresponds to spectro-temporal variation in formant centre frequencies through time in vowel realisations. Nasal rimes give rise to a smaller proportion of correct responses than non-nasal rimes, especially in the context of high and low front vowels: the VISC and changes in vowel height undergone in the context of such articulations, as well as the phonetic consequences of the overall articulatory constellation shape the resulting percept. CVCs with non-nasal rimes give rise to more correct responses than CVVs, despite there being more articulations on-going: the shortness of the vowel in CVCs compensates for this deficit, making perception more robust. Word frequency does not have a significant effect on recognition for any of the syllable types investigated. Overall, a much larger temporal window than the phoneme is required for the robust processing and perceptual integration of speech. Phonemes alone cannot adequately define how the relationship between the phonetic co-extensiveness of different sounds and feature sharing is to be accounted for in speech understanding. Since articulators are in constant motion during production, and consonantal gestures have distinctive coarticulatory influences over vocalic ones, the formant frequencies for both types of sound are in constant flux. This variation reinforces perceptual cohesion and has systematic effects on the mapping of FPD, through which larger structures become audible

Analysis and correction of the helium speech effect by autoregressive signal processing

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