In Vivo Quantification of the Intraglottal Pressure: Modal Phonation and Voice Onset

Objective Assessment of Covid-19 Severity Affecting the Vocal and Respiratory System Using a Wearable, Autonomous Sound Collar

“…These results are consistent with the work carried out on voiceprints. 39 However, the reference respiratory signals show that the variations between the genders were not significant. The signals were collected with an average body temperature of 36.7 °C around the neck.…”

“…These results are consistent with the work carried out on voiceprints. 39 However, the reference respiratory signals show that the variations between the genders were not significant. The signals were For the remainder of this application and the age group examined, we observed that the frequency variations (of the phonic apparatus) resulting from the effects of Covid-19 were much higher than the intergender (M/F) variations, which is why this parameter was not taken into account in our analysis.…”

The Physics of the Human Vocal Folds as a Biological Oscillator

“…However, this divergent form of the glottic channel appears mainly at higher subglottic pressures, when the vibration cycle is characterised by a long-closed phase and a significant phase difference between the lower and upper edges of the VFs. When subglottic pressures are low, as in voice onset, the vertical glottic channel should be shorter [31,32], and the shape differentiation (convergent/divergent)including the phenomena of airflow separation from the glottic wall and vortex formation -should be less pronounced than during sustained modal phonation, or even absent. It is therefore reasonable to assume that the mean motor pressure (from bottom to top) is close to the Bernoulli pressure, estimated numerically over the glottic The Physics of the Human Vocal Folds as a Biological Oscillator DOI: http://dx.doi.org/10.5772/intechopen.113958 surface at the position where the glottis is narrowest.…”

“…As explained above, the luminous flux of the transilluminated trachea is detected by a photovoltaic transducer located in the pharynx. The relative amplitudes of the oscillatory signal are sufficient for some types of studies, e.g., to deal with damping, but other experiments need absolute values of the glottic surface, which requires valid and accurate calibration [32].…”

“…the first derivative of the displacement, i.e. with a phase advance of 90° to the displacement) [32]. Using a model in which the intraglottic pressure P is calculated from the transglottic flow and the velocity of air particles based on Bernoulli's energy law.…”