A laboratory study correlating serial recall performance and speech intelligibility of Chinese language in open-plan offices

Speech noise can reduce occupants' work performance in open-plan offices. Some models have been created to predict the effect of speech of different intelligibility on work performance. However, few of them consider the effects of speech intelligibility in Chinese environments. This study aims to develop a model that evaluates how much work performance is decreased by speech noise with different intelligibility in Chinese open-plan offices. A laboratory experiment has been conducted in this paper to determine the effects of different speech intelligibility on occupants' objective performance of the serial recall task and perceived speech disturbance in Chinese open-plan offices. Then, a prediction model was developed by analyzing the data from this experiment and two previous studies. These two studies researched the effects of the Speech Transmission Index (STI, an objective parameter of speech intelligibility) on the serial recall performance in Chinese environments. According to the prediction model of serial recall performance in Chinese environments, performance decrease occurs within the STI range of 0.31–0.47. The comparison of curves between STI and DP with previous studies shows that the STI range for serial recall performance variation in Chinese environments is narrower than in non-Chinese language environments. Furthermore, the DP average change rate of serial recall tasks in Chinese environments is not less compared to non-Chinese environments, although the effect of speech noise on serial recall performance is lower in the Chinese environment.