Perceptual Voice Quality Evaluation Tools: Normophonic, Pathological, and Sung Voices-A Scoping Review

The objective of this scoping review is to provide an inventory of tools allowing the perceptual evaluation of voice, whether spoken or sung, and uttered in either a pedagogical or a pathological context. It provides details on these tools in terms of the gender and age of the speakers, the nature of the production context, the corpora collected, the language in which the data collection was conducted, and the most frequently considered attributes of voice.

Four online databases were searched, following Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA) guidelines. The descriptor words "perceptual" or "auditory," "assessment" or "evaluation," "voice" or "voice quality," and "rating scale" were principally taken into consideration.

Our initial search revealed 891 studies, of which 105 sources met the eligibility criteria for data extraction. This scoping review highlights the existence of 19 tools that have a name, as well as 45 unnamed tools, most of which consist of four or six ordinal degrees. Most of these tools were developed to perceptually evaluate pathological adult voices, half of them in English. The GRBAS(I) and CAPE-V protocols dominate, but this inventory also shows a wide variety of tools, perceived tasks, evaluated attributes, and combinations thereof. All these results confirm the multidimensional aspect of voice quality, with some attributes that are rarely mentioned but deserve to be highlighted.

The findings of this review allow researchers, clinicians, and educators to understand the various factors and methods that affect the auditory-perceptual evaluations of voice quality. The results may also guide researchers and educators in developing training programs for less-experienced clinicians and educators to improve their confidence in the auditory-perceptual evaluation of voice. New trends for research in the field are pointed out and discussed.