Speech intelligibility (SI) is an important index for the design and assessment of speech purpose hall. The relationship between Chinese speech intelligibility scores in rooms and speech transmission index (STI) under diotic listening condition was studied using monaural room impulse responses obtained from the room acoustical simulation software Odeon in previous paper. The present study employs the simulated binaural room impulse responses and auralization technique to obtain the subjective Chi- nese speech intelligibility scores using rhyme test. The relationship between Chinese speech intelligi- bility scores and STI is built and validated in rooms using dichotic (binaural) listening. The result shows that there is a high correlation between Chinese speech intelligibility scores and STI using di- chotic listening. The relationship between Chinese speech intelligibility scores and STI under diotic and dichotic listening conditions is also analyzed. Compared with diotic listening, dichotic (binaural) listening (an actual listening situation) can improve 2.7 dB signal-to-noise ratio for Mandarin Chinese speech intelligibility. STI method can predict and evaluate the speech intelligibility for Mandarin Chi- nese in rooms for dichotic (binaural) listening.
To explore Chinese Mandarin speech identification in babble of spatially separated talkers,subjective speech identification tests of word and sentence were made with diotic and dichotic listening respectively.The result shows that the speech identification scores changed non-monotonically with the masker number N increasing from 1 to infinity,first declining gradually until reaching their minimums and then rising.Statistical difference was found between the scores of diotic and dichotic listening.For all the values of N checked,dichotic listening achieved higher scores than diotic listening,showing that dichotic effect has an advantage for reducing babble masking.And the scores of sentence test are significantly higher than that of word test with whether diotic or dichotic listening,indicating that the linguistic connection in sentence can help listeners get a better perception of the target speech in babble masking.
