No abstract

The purpose of this paper is to provide a cohesive review of the literature regarding the functional consequences of voice problems and occupational risk factors for them. The salient points are as follows. According to conservative estimates, approximately 28,000,000 workers in the US experience daily voice problems. Many people who experience voice problems perceive them to have a negative impact on their work and their quality of life. Estimates based on empirical data suggest that, considering only lost work days and treatment expenses, the societal cost of voice problems in teachers alone may be of the order of about $2.5 billion annually in the US. In fact, across several countries, "teacher" consistently emerges as the common occupation most likely to seek otorhinolaryngological (ORL) evaluation for a voice problem. Other occupational categories likely to seek ORL examination for a voice problem are singer, counselor/social worker, lawyer, and clergy. Finally, US Census data indicate that keyboard operators may be at special risk for voice problems because of a near-epidemic growth of repetitive strain injury (RSI), which can adversely affect the voice especially when speech recognition software is implemented. This paper discusses frequency data, quality of life data, and treatment considerations for these voice-related occupational issues.

In this study, a double-blind placebo-controlled approach was used to assess the relation between hydration level and phonatory effort. Twelve adult, untrained voice users with normal voices participated as subjects. Each subject received a 4-hour hydration treatment, a 4-hour dehydration treatment, and a 4-hour placebo (control) treatment. Following each treatment, phonatory effort was measured with a physiological measure, phonation threshold pressure (PTP), and with a psychological measure, direct magnitude estimation of perceived phonatory effort (DMEPPE). Summarizing the results across these measures, the findings indicated an inverse relation between phonatory effort and hydration level, but primarily for high-pitched phonation tasks. The findings for PTPs replicated those from an earlier study conducted without double-blind experimental manipulations (Verdolini-Marston, Titze, & Druker, 1990). Theoretical discussion focuses on the possible role of vocal fold tissue viscosity for hydration and dehydration effects, although direct measures of tissue viscosity are lacking.