Verifying two commercial software implementations of impulse-response-based speech intelligibility measurements

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


A number of objective evaluation methods are currently used to quantify the speech intelligibility in a built environment, including the speech transmission index (STI), rapid speech transmission index (RASTI), articulation index (AI), and the percent articulation loss of consonants (%ALCons). Certain software programs can quickly evaluate STI, RASTI, and %ALCons from a measured room impulse response. In this project, two impulse-response-based software packages (WinMLS and SIA-Smaart Acoustic Tools) were evaluated for their ability to determine intelligibility accurately. In four different spaces with background noise levels less than NC 45, speech intelligibility was measured via three methods: (1) with WinMLS 2000; (2) with SIA-Smaart Acoustic Tools (v4.0.2); and (3) from listening tests with humans. The study found that WinMLS measurements of speech intelligibility based on STI, RASTI, and %ALCons corresponded well with performance on the listening tests. SIA-Smaart results were correlated to human responses, but tended to under-predict intelligibility based on STI and RASTI, and over-predict intelligibility based on %ALCons.

Original languageEnglish (US)
Pages (from-to)717-728
Number of pages12
JournalApplied Acoustics
Issue number7
StatePublished - Jul 2007


  • Articulation index
  • Impulse response
  • Intelligibility
  • Speech
  • Speech transmission

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

Fingerprint Dive into the research topics of 'Verifying two commercial software implementations of impulse-response-based speech intelligibility measurements'. Together they form a unique fingerprint.

Cite this