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

Abstract

Recent literature regarding vocal hydration is high quality evidence. Systemic hydration is the easiest and most cost-effective solution to improve voice quality. Recent evidence therefore supports the inclusion of hydration in a vocal hygiene program.

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

“…Once Φ(t) is known, P(z, t) along the constricted channel portion is estimated using (1). The term describing the viscous pressure drop contribution in (1) and (2) needs to be reconsidered when a two-phase air-water mixture occurs.…”

“…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.…”

Effects of Humidification of the Vocal Tract and Respiratory Muscle Training in Women With Voice Symptoms—A Pilot Study

“…Overall, however, there has been a paucity of research on the humidification of voice organs, and despite the good quality of the existing studies, robust evidence for the effectiveness of hydration treatments has been lacking until recently [28], and the results have also been somewhat contradictory [10,29]. Studies exploring the effects of laryngeal humidification on voice quality and its acoustically measured parameters have been particularly sparse.…”

In Reference to A 10‐Year Study of the Etiopathogenesis of Cysts With a Study of Seromucinous Glands in Vocal Folds

“…1 First, the daily consumption of ≤4 glasses of water/ beverages was used to define VF dehydration, without consideration of many factors influencing the VF hydration assessment including medication, daily activity, environmental humidity, and the reflux that leads to pathophysiological mechanisms of mucus dehydration. 2,3 The authors used the reflux finding score (RFS) for the reflux diagnosis, but the RFS-reported findings are nonspecific and encountered in healthy subjects 4 or in patients with vocal abuse. 5 The vocal abuse origin hypothesis was based on the high clinical proportion of VFRCs in the striking zone, which had a low proportion of seromucinous glands in a cadaveric study.…”