Voice source, formant frequencies and vocal tract shape in overtone singing. A case study.

In overtone singing a singer produces two pitches simultaneously, a low-pitched, continuous drone plus a melody played on the higher, flutelike and strongly enhanced overtones of the drone. The purpose of this study was to analyse underlying acoustical, phonatory and articulatory phenomena. The voice source was analyzed by inverse filtering the sound, the articulation from a dynamic MRI video of the vocal tract profile, and the lip opening from a frontal-view video recording.

Do 'Dominant Frequencies' explain the listener's response to formant and spectrum shape variations?

Psychoacoustic experimentation shows that formant frequency shifts can give rise to more significant changes in phonetic vowel timber than differences in overall level, bandwidth, spectral tilt, and formant amplitudes. Carlson and Granström's perceptual and computational findings suggest that, in addition to spectral representations, the human ear uses temporal information on formant periodicities ('Dominant Frequencies') in building vowel timber percepts. The availability of such temporal coding in the cat's auditory nerve fibers has been demonstrated in numerous physiological investigations undertaken during recent decades.

A duration-dependent account of coarticulation for hyper- and hypoarticulation.

Previous studies investigating anticipatory coarticulation in emphatically stressed CV sequences and during fast speaking rates reported that three factors contributed to the overall extent of the documented coarticulation. These factors were: (1) vowel identity, (2) vowel space expansion (emphasis) or reduction (fast rate), and a hypothesized (3) 'deeper' and 'shallower' stop closure contact in emphatic and faster speech, respectively. The objective of the current research was to conceptually and quantitatively unify these two studies.

Laryngeal mechanisms in speech: The contributions of Jan Gauffin.

Jan Gauffin was an early user of fiber optics which allowed him to discover that laryngeal structures above the glottal level are involved in speech. His research led him to postulate three independently controlled mechanisms: fundamental frequency control, glottal adduction/abduction, and laryngealization, the latter derived from the protective closure function. He argued that phonetic theory must be revised to account for the main phonation types of the world's languages.

The effect of speaking rate on consonant vowel coarticulation.

In 2007 Lindblom et al. introduced a methodological tool to disentangle consonant-vowel (CV) coarticulation attributable to emphatic stress apart from the vowel expansion effects known to accompany the prosodic overlay. After empirically accounting for the altered vowel positions, they reported small but consistent increases in F2 transition onsets in emphatically produced CVs that could not be attributed to vowel context influences, and that differed across stop place.

The effect of emphatic stress on consonant vowel coarticulation.

This study assessed the acoustic coarticulatory effects of phrasal accent on [V1.CV2] sequences, when separately applied to V1 or V2, surrounding the voiced stops [b], [d], and [g]. Three adult speakers each produced 360 tokens (six V1 contexts x ten V2 contexts x three stops x two emphasis conditions).

Stop place coding: an acoustic study of CV, VC#, and C#V sequences.

This study investigated stop + vowel coarticulation as a coding mechanism for differentiation of stop place categories in an F2-defined stimulus space. Locus equations (LEs) were used to index the extent of coarticulation in three contexts: (1) onset stop + vowel utterances [.CV]; (2) within-syllable vowel + coda stop utterances [VC#], and (3) across-syllable/word coda stop + vowel utterances [C#V].

The trough effect: implications for speech motor programming.

While the existence of the trough effect is unquestioned, its theoretical significance is unknown. A multifaceted instrumental approach - spectrographic, cineradiographic, and vocal tract modeling - was used to document the trough effect in open (V.CV) and closed (VC.