Using the short-time speech transmission index to predict speech reception thresholds in fluctuating noise

• Published in: The Journal of the Acoustical Society of America 2014-04, Vol.135 (4_Supplement), p.2224-2225
• Main Authors: Ferreira, Matthew, Payton, Karen
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4877272

The Speech Transmission Index (STI) predicts the intelligibility of speech degraded by noise and reverberation. Recently, Payton and Shrestha [J. Acoust. Soc. Am. 134, 3818–3827 (2013)] reported on the ability of a short-time speech-based STI (ssSTI) to predict the intelligibility of speech in the presence of fluctuating noise using analysis windows shorter than 1 s. They found the ssSTI highly correlated with theoretical STI calculations using windows as short as 0.3 s. In the current work, extended versions of the ssSTI were investigated for their ability to improve speech intelligibility prediction in the presence of fluctuating noise; a condition for which the long-term STI incorrectly predicts the same intelligibility as for stationary noise. No STI metric predicts a normal-hearing listener's improved ability to perceive speech in the presence of fluctuating noise as compared to stationary noise at the same signal-to-noise ratio. The investigated technique used window lengths that varied with octave band, based on human auditory temporal resolution as in the Extended Speech Intelligibility Index [Rhebergen and Versfeld, J. Acoust. Soc. Am. 117, 2181–2192 (2005)]. An extended sSTI using speech-shaped noise instead of speech as a probe predicted published speech reception thresholds for a variety of conditions.