Gender differences in vocal doses among occupational voice users: a systematic review of literature and meta-analysis

Abstract

Background Occupational voice users such as teachers, singers, and broadcasters have high vocal demands increasing the risk for developing voice disorders. Among occupational voice users, the literature has report gender differences in vocal doses as part of vocal demands. However, these differences have not been quantified. Objective To determine differences per gender on vocal doses among different groups of occupational voice users. Methods A systematic review of literature and meta-analysis were conducted on publications about vocal dose among occupational voice users. In total, 242 potential articles were found. After screening of titles and abstracts, 16 papers were included for full revision in the systematic review of literature. For the meta-analysis, 7 out of 16 papers were included. Results Females had higher phonation time percentage compared with males (mean difference = 1.44, p value = .16). Nevertheless, this difference was not statistically significant. Among call centre operators, there was no difference in time doses associated with gender. Sport teachers had high values in time dose percentage, dissipation, and radiated energies. Conclusions The meta-analysis shows variations in time doses, which could be associated with the vocal demand responses for females compared with males in occupational voice settings. Future investigations are required for establishing safe limits criteria for vocal doses, as well as vocal functioning in different working context.