Neutral or ambiguous voices: a scoping review protocol

The search strategy will include the PCC elements and will be adapted for each source of evidence. Study Selection All records identified through the search strategy will be imported into Rayyan for reference management and duplicate removal. Studies will be selected in two stages: (1) screening of titles and abstracts according to the inclusion criteria; (2) full-text assessment according to the eligibility criteria.

Two independent reviewers will perform the selection, and disagreements will be resolved by consensus. When necessary, a third reviewer will be consulted. Duplicate records and studies not available in full text will be excluded.

Data Extraction and Analysis Data extraction will be conducted using a protocol developed by the authors. The extracted data will include: a) publication characteristics; b) methodological design; c) terminology and conceptual definitions; d) type of voice (natural, modified, or synthesized); e) population characteristics; f) perceptual and acoustic methods; g) main findings. The extraction protocol may be refined during the review process.

Results will be presented descriptively through tables and figures.