The Interaction of Surface Hydration and Vocal Loading on Voice Measures

The Effect of Hydration on Voice Quality in Adults: A Systematic Review

“…The increase was considered as a positive finding as the vocal folds may have become lighter and thus able to vibrate quicker when well lubricated [2]. No statistical difference was found for the effect of low and moderate humidity on relative fundamental frequency (p=0.97) or the cepstral peak prominence (CPP) (P>0.05) [44] or the low/high ratio (LHR) (p>0.05) [45]. Superficial hydration also did not have significant effects on noise, the aperiodic component of the signal (p=0.668), the irregularity of the voice over time (p=0.795), or the glottal-to-noise excitation ratio (GNE) (p=0.616).…”

“…Perceptual characteristics in CAPE-V scores (p=0.171) also revealed nonsignificance [44]. looked at the effect of oral desiccation and subsequent rehydration using nebulization of an isotonic saline solution [25].…”

Pressure drop for adiabatic air-water flow through a time-varying constriction

“…10,13,35,37 However, this assumption of singlephase airflow is in contrast to the physiological reality and is reported to affect flow-induced phenomena such as the shown effect of surface (de-)hydration on human voiced speech sound production. 1,17,36 When the presence of liquid is accounted for, adiabatic two-phase gas-liquid flow occurs. It is well established that the mixture viscosity of gas-liquid two-phase flow strongly influences the pressure drop and thus the forces exerted by the flow on the surrounding channel walls driving fluid-structure interactions and associated phenomena such as voiced speech sound production, brass instruments play, whistling, etc.…”

Self-Ratings of Vocal Status in Daily Life: Reliability and Validity for Patients With Vocal Hyperfunction and a Normative Group

“…Because all the previously cited ambulatory studies only tracked subjects with normal voices, results may not accurately represent pathological vocal status changes but instead provide insights into solely the normative (i.e., nonpathological) aspects of vocal deterioration and recovery. In addition, study designs using vocal loading tasks artificially elicit vocal status changes in participants with normal voices (Fujiki, Chapleau, Sundarrajan, McKenna, & Sivasankar, 2016;Remacle, Finck, Roche, & Morsomme, 2012;Whitling, Rydell, & Åhlander, 2015); therefore, results cannot be assumed to accurately represent pathological vocal conditions such as VH. For example, patients with VH-who are in chronic pathological vocal states-might not fluctuate in the same manner as those with normal voices.…”