Laryngeal Desiccation Challenge and Nebulized Isotonic Saline in Healthy Male Singers and Nonsingers: Effects on Acoustic, Aerodynamic, and Self-Perceived Effort and Dryness Measures.

OBJECTIVES

This study examined the effects of a laryngeal desiccation challenge and nebulized isotonic saline on voice production in young, healthy male singers and nonsingers.

STUDY DESIGN

This is a prospective, double-blind, within-subjects experimental design.

METHODS

Participants included 10 male university-trained singers and 10 age-matched nonsingers (mean age, 21.8 years; range, 18-26 years) who underwent a 30-minute oral breathing laryngeal desiccation challenge using medical grade dry air (<1% relative humidity) on two occasions in consecutive weeks. After the challenge, participants received either 3 mL or 9 mL of nebulized isotonic saline (0.9% NaCl); order of administration was counterbalanced. Phonation threshold pressure (PTP), the cepstral spectral index of dysphonia (CSID) for sustained vowels and connected speech, and self-perceived vocal effort, mouth dryness, and throat dryness were measured at each recording (baseline, after challenge, and at 5, 35, and 65 minutes after treatment).

RESULTS

Self-perceived effort and dryness measures increased (worsened) after desiccation challenge and decreased (improved) after nebulized treatment (P < 0.05). No consistent changes were observed for PTP or CSID over time. Overall, singers demonstrated significantly lower vocal effort and CSID as compared with nonsingers.

CONCLUSIONS

Young, vocally healthy men may not experience physiologic changes in voice production associated with laryngeal desiccation and nebulized saline treatments; however, self-reported increases in vocal effort which are associated with dryness symptoms might improve with nebulized treatments. Future hydration research should consider age and sex variables.