Larm Petra, Hongisto Valtteri
Laboratory of Ventilation and Acoustics, Finnish Institute of Occupational Health, Lemminkäisenkatu 14-18 B, FIN-20520 Turku, Finland.
J Acoust Soc Am. 2006 Feb;119(2):1106-17. doi: 10.1121/1.2146112.
During the acoustical design of, e.g., auditoria or open-plan offices, it is important to know how speech can be perceived in various parts of the room. Different objective methods have been developed to measure and predict speech intelligibility, and these have been extensively used in various spaces. In this study, two such methods were compared, the speech transmission index (STI) and the speech intelligibility index (SII). Also the simplification of the STI, the room acoustics speech transmission index (RASTI), was considered. These quantities are all based on determining an apparent speech-to-noise ratio on selected frequency bands and summing them using a specific weighting. For comparison, some data were needed on the possible differences of these methods resulting from the calculation scheme and also measuring equipment. Their prediction accuracy was also of interest. Measurements were made in a laboratory having adjustable noise level and absorption, and in a real auditorium. It was found that the measurement equipment, especially the selection of the loudspeaker, can greatly affect the accuracy of the results. The prediction accuracy of the RASTI was found acceptable, if the input values for the prediction are accurately known, even though the studied space was not ideally diffuse.
在诸如礼堂或开放式办公室的声学设计过程中,了解在房间的各个区域语音是如何被感知的很重要。已经开发出了不同的客观方法来测量和预测语音清晰度,并且这些方法已在各种空间中得到广泛应用。在本研究中,对两种这样的方法进行了比较,即语音传输指数(STI)和语音清晰度指数(SII)。还考虑了STI的简化形式,即室内声学语音传输指数(RASTI)。这些量都是基于在选定频段上确定一个表观信噪比,并使用特定权重将它们相加得到的。为了进行比较,需要一些关于这些方法因计算方案以及测量设备而可能产生的差异的数据。它们的预测准确性也备受关注。在一个噪声水平和吸声可调节的实验室以及一个实际的礼堂中进行了测量。结果发现,测量设备,尤其是扬声器的选择,会极大地影响结果的准确性。研究发现,如果预测的输入值准确已知,即使所研究的空间并非理想的扩散空间,RASTI的预测准确性也是可以接受的。