Relationship between Chinese speech intelligibility and speech transmission index in rooms based on auralization

Based on simulated monaural and binaural room impulse responses, the relationship between Chinese speech intelligibility scores and speech transmission index (STI) including the effect of noise is investigated using a phonetically balanced test in virtual rooms. The results show that Chinese speech intelligibility scores increase monotonically with STI values. The correlation coefficients are 0.95, 0.90 and the standard deviation is 5.6%, 6.7% under diotic and dichotic listening conditions, respectively. Compared with diotic listening based on monaural room impulse responses, dichotic listening based on binaural room impulse responses can improve by 2.7 dB signal-to-noise ratio for Chinese speech intelligibility. The STI method can better predict and evaluate Chinese speech intelligibility in rooms.

► We investigated relationship between Mandarin Chinese speech intelligibility and STI in rooms using auralization.
► Chinese speech intelligibility scores increase monotonically with STI values.
► The correlation coefficients are 0.95, 0.90 under diotic and dichotic listening conditions, respectively.
► The correlation coefficients are 0.95, 0.90 under diotic and dichotic listening conditions, respectively.
► Compared with diotic listening, dichotic listening can improve by 2.7 dB SNR for Chinese speech intelligibility.
► The STI with noise can better predict and evaluate the Mandarin Chinese speech intelligibility in rooms.