Automated tracking of quantitative parameters from single line scanning of vocal folds: A case study of the 'messa di voce' exercise

This article presents a novel application of the 'single line scanning' of the vocal fold vibrations (kymography) in singing pedagogy, particularly in a specific technical voice exercise: the 'messa di voce'. It aims at giving the singer relevant and valid short-term feedback. A user-friendly automatic analysis program makes possible a precise, immediate quantification of the essential physiological parameters characterizing the changes in glottal impedance, concomitant with the progressive increase and decrease of the lung pressure. The data provided by the program show a strong correlation with the hand-made measurements. Additional measurements such as subglottic pressure and flow glottography by inverse filtering can be meaningfully correlated with the data obtained from the kymographic images

Théorie oscillo-impédantielle de la vibration des cordes vocales / P. Dejonckere ; promoteur : J. Van Den Eeckhaut

Thèse d'agrégation de l'enseignement supérieur (Faculté de médecine) -- UCL, 198

The comparison of auditory behavioral and evoked potential responses (steady state and cortical) in subjects with occupational noise-induced hearing loss.

OBJECTIVE: To define difference scores between PTA, ASSR and CERA thresholds in subjects with occupational NIHL. DESIGN: 44 subjects undergoing a medico-legal expert assessment for occupational NIHL and fulfilling criteria of reliability were considered. Assessment included: PTA, 40 Hz binaural multiple ASSR and CERA (1-2-3 kHz). RESULTS: The respective average difference scores (ASSR - PTA) for 1, 2 and 3 kHz are 13.01 (SD 10.19) dB, 12.72 (SD 8.81) dB and 10.38 (SD 8.19) dB. The average (CERA - ASSR) difference scores are 1.25 (SD 14.63) dB for 1 kHz (NS), 2.73 (SD 13.03) dB for 2 kHz (NS) and 4.51 (SD 12.18) dB for 3 kHz. The correlation between PTA and ASSR (0.82) is significantly stronger than that between PTA and CERA (0.71). In a given subject, PTA thresholds are nearly always lower (i.e., better) than ASSR thresholds, whatever the frequency (1-2-3 kHz) and the side (right - left). A significant negative correlation is found between the difference score (ASSR - PTA) and the degree of hearing loss. CONCLUSION: ASSR outperforms CERA in a medicolegal context, although overestimating the behavioral thresholds by 10-13 dB

"Advanced Voice Function Assessment"-Goals and activities of COST Action 2103

The COST Action 2103 "Advanced Voice Function Assessment" is a joint initiative of speech processing teams (engineers and physicists) and the European Laryngological Research Group (ELRG) (laryngologists/phoniatricians). The Action officially started in December 2006, and is running till the end of 2010. 17 European countries are involved. A main objective is a better understanding of the relationship between biomechanical changes at the level of the vocal folds - as induced by pathology and tissue reaction to strain - and alterations of the acoustical voice signal. This needs to result in developing accurate, objective and clinically useful methods of investigation of voice quality in patients, and of strategies for preventing occupational voice disorders in professional speakers. Modelling is an essential tool in this process. © 2009 Elsevier Ltd. All rights reserved

Lung volume affects the decay of oscillations at the end of a vocal emission

At the end of a vocal emission, when the voicing is not interrupted by a laryngeal closure, a damped oscillatory motion of each vocal fold can be observed after the last contact phase of the two fold edges on the midline. It can be precisely analysed using a measure of transglottal light intensity (photoglottography). Actually, during modal phonation, the vocal oscillator mainly comprises two components: the vocal folds themselves and the vibrating air mass. A simple calculation suggests that the internal air mass set into vibration is larger than the vocal fold mass. In order to investigate the effect of the vibrating air mass, a voicing protocol was elaborated for validly measuring and comparing damping characteristics in two conditions: at high and at low lung volume, ceteris paribus. Glottal area, intraoral pressure, electroglottogram and sound were recorded simultaneously. Elaborated voicing protocol consisted in series of fast repetitions (3–4 s−1) of the vowel /ε/, each vocalization being followed by an abrupt bilabial occlusion with complete airflow interruption. The average difference in lung volume between the two conditions is approximately 2410 mL. The results show that the decay of vocal fold oscillation is influenced by the amount of lung air that is set into oscillation. A reduction of the air volume leads to a significant increase in the rate of decay, thus voicing at low lung volume requires more energy, which is of importance for voice hygiene

Medicolegal decision making in noise-induced hearing loss-related tinnitus.

In some patients with occupational noise-induced hearing loss, a significant aspect of the handicap concerns the concomitant tinnitus; thus, this disorder must be considered in evaluating a disability percentage in the insurance context. The main difficulty comes from the lack of objective measures for tinnitus. To reach a maximum of medicolegal objectivity, a system was developed within the Belgian Institute of Occupational Disorders (Brussels) in the form of a four-level decision structure, after exhaustive but noninvasive assessment of patients. An aggregate of multiple-choice responses (affirmative, neutral, negative) to elementary questions leads to a decision of the next level, which in turn determines--together with the other decisions at the same level--the conclusion at a still higher level. A positive outcome on all four level-3 questions is required for recognition of noise-induced hearing loss-related tinnitus as an occupational disorder and for financial compensation (final decision, level 4). We assessed 10 exemplary files on which this system was applied by four experts rating independently. A variant of Cohen's Kappa for multiple raters demonstrated high interrater consistency at the first level. In all cases, the decisions at levels 3 and 4 were identical. In this way, the final medicolegal decision relies on standardized criteria and becomes perfectly transparent

The dynamics of vocal onset

Vocal onset is the process occurring between the first detectable oscillatory glottal movement and the steady state vibration of the vocal folds. To some extent, the voice onset mirrors the voice offset. High speed imaging, photo-, electro-, flow- and ultrasonoglottography and sound analysis have been used in combinations to allow detailed qualitative insight into the phenomenon. Moreover, the instantaneous intraglottal pressure can be computed from the combined records of transglottal airflow and glottal area. A large number of vocal onsets of different types were analysed in various conditions of modal healthy phonation. Vocal folds (VF) vibration can start either from a closed glottis (hard onset) or from an open glottis (soft/breathy onset). In a soft onset, the amplitude of oscillations progressively increases over 2 to more than 30 cycles, before the first clear closed plateau is achieved. It is not possible to define whether the first movement of VF is towards medial or lateral. Hard, soft and breathy onsets can be clearly identified. Flow- and photoglottography are the most sensitive signals in detecting the first glottal movements in soft and breathy onsets. The shape of the EGG signal depends on the contact of the VF edges. The duration of the onset phase is to some extent related to VF adduction speed and peak expiratory flow. The ultrasound technique is sensitive, but lacks physiological interpretation. From the first onset-cycles on, the intraglottal pressure during the opening phase of the glottis exceeds that during the closing phase. During soft/breathy onsets with a sufficiently large number of cycles, when the vibrating mass increases, a trend appears toward a slight progressive decrease of the fundamental frequency of the oscillations, likely related to the increasing vibrating mas