To cite package ‘SII’ in publications use:

  Warnes GR, Shaver M (2026). _SII: Calculate ANSI/ASA S3.5-1997
  (R2024) Speech Intelligibility Index_. R package version 1.3.0,
  <https://CRAN.R-project.org/package=SII>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {SII: Calculate ANSI/ASA S3.5-1997 (R2024) Speech Intelligibility
Index},
    author = {Gregory R. Warnes and Mark Shaver},
    year = {2026},
    note = {R package version 1.3.0},
    url = {https://CRAN.R-project.org/package=SII},
  }