Mathematical model of speech intelligibility in mosque with column pillars

Abstract

The mosques in Malaysia are normally built in large scale with at least 280 m3 in volume. These large mosques usually have domes as partial of the ceiling and column pillars to support the large areas of the ceiling. The existence of domes and column pillars in large rooms can introduce a problem in speech intelligibility. Column pillars in the main prayer hall are usually covered with decorated tiles which are very reflective surfaces. The reflected sounds from such surfaces can create sound shadow zone between those pillars. This research explores effects of the column pillars in mosque towards speech intelligibility. This fundamental knowledge is required for optimum audio quality and predicting speech intelligibility for mosque. The research objectives are to conduct topology study of column pillars in mosques, to perform parameters selection in mosques with column pillars to evaluate its speech intelligibility, and to quantify the speech intelligibility in mosques with column pillars. From analysis of the result it can be concluded that the number of room samples chosen, and the number of measured speech intelligibility scores are sufficient to predict speech intelligibility in room with column pillars. By using only two room dimension parameters, the DSL and DFL in this case, the developed mathematical expressions have already achieved credible minimum coverage of statistical data of credible prediction accuracy of 71%. The mathematical expression development improved to a significant minimum coverage of statistical data of credible prediction accuracy of 93% when four room dimension parameters have been used.