Investigating the effects of moderate humidity in reducing dehydration induced vocal decrement

and

Effects of aging on the respiratory and the laryngeal system

Anusha Sundarrajan

Ph.D. Mentors:

Jessica Huber, Ph.D.

Preeti Sivasankar, Ph.D.

The presentation will include a summary of two studies.

Study 1: Study 1 was conducted to see the impact of oral breathing in low humidity environment on voice and if the effects can be reversed following a moderate humidity challenge. We hypothesized that moderate humidity will reverse the vocal decrement induced by oral breathing in low humidity. Healthy adults aged 18 to 45 years participated in this investigation. Voice measures of phonation threshold pressure (PTP) and perceived phonatory effort (PPE) were collected prior to and after each challenge. The results of the study demonstrate no significant changes in PTP and PPE with humidity. Thus, humidity does not mediate the effects of a speaking challenge on the voice.

Study 2: With a thorough understanding of the voice measures used in Study 1, we propose a study to investigate the effect of aging on respiration and voice. Few studies have collected measures related to laryngeal function and respiratory capacities within the same research design. We propose to recruit 30 healthy male and female adults aged between 18-80 years. The study design will include collection of respiratory and laryngeal measures before and after the performance of a prolonged speaking task. We hypothesize that individuals will have increased lung pressure and vocal effort after the fatiguing challenge. We expect older adults to use higher lung volume initiations, terminations, and excursions, but to produce shorter utterances as compared to young adults. The age-related differences will be more apparent after the speaking (fatiguing) challenge. Data from the current study will help us better understand the normal mechanism of aging and also assist in understanding the differences between typical aging and diseases associated with aging.