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Purpose: Good verbal signals and low background noise are key factors for all children to maximize understanding of what is being taught. Classroom shape, surroundings, and even furnishings change how the environment “sounds” and how speech is “heard” in the classroom. Classroom acoustics is perhaps one of the most important, but often least considered, factors when designing a classroom. This systematic review aimed to characterize the relationship between intelligibility of speech and room acoustics in elementary schools based on the available evidence. Method: Eligible studies were identified using two computerized databases: PubMed and Scopus. In total, 23 publications met our inclusion criteria: (a) Participants must have been from elementary schools, (b) acoustic characterization of the classroom must have been provided, (c) intelligibility tests must have been performed, and (d) articles were written in English. Results: After identifying the parameters and tests used to quantify the intelligibility of speech, the speech intelligibility scores were analyzed in relation with acoustical parameters found in the articles, particularly signal-to-noise ratio and speech transmission index. Our results highlighted the negative effect on intelligibility associated with poor transmission of the speech and poor classroom acoustics caused by long reverberation times and high background noise. Conclusion: Good classroom acoustics is needed to improve speech intelligibility and, therefore, increase children's academic success.

PurposeThe purpose of this document is threefold: (a) review the uses of the terms “vocal fatigue,” “vocal effort,” “vocal load,” and “vocal loading” (as found in the literature) in order to track the occurrence and the related evolution of research; (b) present a “linguistically modeled” definition of the same from the review of literature on the terms; and (c) propose conceptualized definitions of the concepts.MethodA comprehensive literature search was conducted using PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scientific Electronic Library Online. Four terms (“vocal fatigue,” “vocal effort,” “vocal load,” and “vocal loading”), as well as possible variants, were included in the search, and their usages were compiled into conceptual definitions. Finally, a focus group of eight experts in the field (current authors) worked together to make conceptual connections and proposed consensus definitions.ResultsThe occurrence and frequency of “vocal load,” “vocal loading,” “vocal effort,” and “vocal fatigue” in the literature are presented, and summary definitions are developed. The results indicate that these terms appear to be often interchanged with blurred distinctions. Therefore, the focus group proposes the use of two new terms, “vocal demand” and “vocal demand response,” in place of the terms “vocal load” and “vocal loading.” We also propose standardized definitions for all four concepts.ConclusionThrough a comprehensive literature search, the terms “vocal fatigue,” “vocal effort,” “vocal load,” and “vocal loading” were explored, new terms were proposed, and standardized definitions were presented. Future work should refine these proposed definitions as research continues to address vocal health concerns.