Gaps and Future Directions in the Research About Masking and Voice Production: Bibliometric Analysis, Systematic...

While facemasks have played a vital role in mitigating the spread of infectious diseases, their prolonged use has raised questions about their potential effects on voice production and communication.

The present study integrated three complementary methodological approaches with three specific aims. First, to identify trends in research on facemasks and voice production, including thematic clusters and patterns, using bibliometric methods. Second, critically appraise and synthesize findings from primary research studies on the effects of facemask use on voice-related outcomes through a systematic literature review. Third, to determine the pooled effects of facemask use on selected vocal outcomes, where data allow, using meta-analysis.

In total, 48 publications were included in this review. The term co-occurrence network map generated with VOSviewer showed three clusters: voice-related consequences of mask use during the COVID-19 pandemic, the impact of protective equipment on speech acoustics and intelligibility, and acoustic markers of voice quality in healthy speakers. The overlay visualization map showed that earlier studies emphasized the subjective assessment of the relationship between facemasks and voice production. In contrast, more recent publications reflect a growing interest in the instrumental assessment of the relationship. Most studies based their results on voice acoustic analysis, followed by questionnaires and aerodynamic assessment. The results suggested no significant differences in fundamental frequency, jitter, shimmer, harmonics-to-noise ratio, and maximum phonation time. The results on vocal effort and sound pressure levels are inconsistent. The meta-analysis suggested that facemasks cause a small increase in SPL, but the effect was not statistically significant.

Facemasks create complex communication challenges that extend beyond acoustic changes to encompass multimodal perception disruption and disproportionate impacts on vulnerable populations. While acoustic measurements show minimal direct effects, the elimination of visual speech cues and facial expression recognition may create substantial barriers for individuals with hearing impairments, developmental disabilities, and age-related communication difficulties.