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ABSTRACT: Vocal exercises that increase the vocal tract impedance are widely used in voice training and therapy. The present study applies a versatile methodology to investigate phonation during varying artificial extension of the vocal tract. Two males and one female phonated into a hard-walled plastic tube (phi 2 cm), whose physical length was randomly pair-wise changed between 30 cm, 60 cm and 100 cm. High-speed image (1900 f/sec) sequences of the vocal folds were obtained via a rigid endoscope. Acoustic and electroglottographic signals (EGG) were recorded. Oral pressure during shuttering of the tube was used to give an estimate of subglottic pressure (Psub). The only trend observed was that with the two longer tubes compared to the shortest one, fundamental frequency was lower, open time of the glottis shorter, and Psub higher. The results may partly reflect increased vocal tract impedance as such and partly the increased vocal effort to compensate for it. In other parameters there were individual differences in tube length-related changes, suggesting complexity of the coupling between supraglottic space and the glottis.
Logopedics Phoniatrics Vocology 02/2007; 32(4):157-64. · 0.84 Impact Factor
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ABSTRACT: To investigate the prevalence of asymmetries at vocal fold adduction, 109 vocally healthy subjects between 22 and 80 years of age were examined. All subjects were examined with a rigid endoscope and video recorded. The recordings were analysed off line by two laryngologists. Seventy percent of the subjects displayed some kind of asymmetry. There was no difference between the sexes. Side differences in antero-posterior position of the corniculate or cuneiform tubercles were the most frequent asymmetries, occurring in 66% of the total material and in 92% of the asymmetrical cases. Asymmetries appeared more common and more marked in older subjects and possibly more frequent in singers than in non-singers. Laryngeal adduction asymmetries are probably of little importance for voice function.
Logopedics Phoniatrics Vocology 02/2004; 29(3):128-34. · 0.84 Impact Factor
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ABSTRACT: Co-vibrations of the ventricular folds are a common finding in the clinical setting. It is not always obvious how much of the perceived voice change can be attributed to the presence of such vibrations. The aim of the present study was to describe laryngeal vibrations as observed by high-speed imaging in cases where ventricular fold vibrations had been observed. The findings at kymographic display of the recordings were correlated to perceptual measures and spectrographic observations. Two subjects, a 65-year-old man with chronic laryngitis and one vocally healthy man, were examined during pressed and breathy sustained phonation. Perceived roughness in the voice quality correlated to irregularities in true vocal fold vibrations as well as to irregular ventricular fold vibrations with large amplitude combined with sufficient closure. In none of the recorded sections did ventricular fold vibrations occur without simultaneous true vocal fold vibrations. Regular vibrations of the ventricular folds of the same frequency as those of the true vocal folds and with a reciprocal pattern did not contribute to any roughness in the perceived voice.
Logopedics Phoniatrics Vocology 02/2004; 29(4):162-70. · 0.84 Impact Factor
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INTERSPEECH 2004 - ICSLP, 8th International Conference on Spoken Language Processing, Jeju Island, Korea, October 4-8, 2004; 01/2004
