Dynamic vocal analysis: vocal functionality evaluation

Dynamic vocal analysis (DVA) is an auditory-perceptual and acoustic vocal assessment strategy that provides estimates on the biomechanics and aerodynamics of vocal production by performing frequency and intensity variation tasks and using voice acoustic spectrography. The objective of this experience report is to demonstrate the use of DVA in the assessment of vocal functionality of dysphonic and non-dysphonic individuals, with a special focus on the laryngeal musculature. Phonatory tasks consisted of sustained vowel, "a" or "é", and/or connected speech, in three intensities (habitual, soft, and loud) and three frequencies (habitual, high, and low), as well as ascending and descending glissando. The adjustments of the laryngeal and paralaryngeal muscles can be inferred from the different DVA tasks. The main characteristics of the laryngeal muscles analyzed are control of glottic adduction, stretching, and shortening of the vocal folds; the main characteristics of the paralaryngeal musculature are mainly related to the vertical laryngeal position in the neck. While the sustained vowel evaluates the vocal functionality with a focus on the larynx, connected speech allows the evaluation of the articulatory adjustments employed. An acoustic spectrographic software can be used to visualize the performance of such tasks. The clinical application of the DVA will be exemplified using acoustic spectrography plates from normal and dysphonic voices, taken from a voice bank. Individuals who perform the DVA tasks in a balanced way, with adequate vocal quality and without phonatory effort, demonstrate good vocal functionality. On the other hand, difficulties in performing these tasks with worsening vocal quality and/or increased muscle tension may be indications of altered vocal functionality.