Accuracy of speech transmission index predictions based on the reverberation time and signal-to-noise ratio

作者：Galbrun Laurent^*; Kitapci Kivanc

来源：APPLIED ACOUSTICS, 2014, 81: 1-14.

DOI：10.1016/j.apacoust.2014.02.001

• Acoustic measurements
• Room acoustics
• Speech intelligibility
• Sound quality

This paper examines the accuracy of the speech transmission index (STI) calculated from the reverberation time (T) and signal-to-noise ratio (L-SN) of enclosed spaces. Differences between measured and predicted STIs have been analysed in two rooms (reverberant vs. absorbent), for a wide range of absorption conditions and signal-to-noise ratios (sixteen tests). The STI was measured using maximum length sequence analysis and predictions were calculated using either measured or predicted values of T and L-SN, the latter assuming diffuse sound field conditions. The results obtained for all the conditions tested showed that STI predictions based on T and L-SN tend to underestimate the STI, with differences between measured and predicted SIN always lower than 0.1 (on a 0.0-1.0 scale), and on average lower than 0.06. According to previous research, these differences are noticeable and therefore non-negligible, as 0.03 is the just noticeable difference in STI. The use of either measured or predicted values of T and L-SN provided similar STI predictions (i.e. non-noticeable changes), with differences between predictions that are on average lower than 0.03 for the absorbent room, and lower than 0.01 for the reverberant room.

• 出版日期2014-7