Evaluation and quantification of sound intelligibility (SdI): Metro commercial spaces as an example

Abstract

Sound intelligibility (SdI) is investigated in the context of modelling aural comfort in the design of metro commercial spaces. The term describes an individual's clear aural perception of their surrounding environment. The present paper describes the key objective variables used to evaluate and quantify SdI for inclusion in models predicting aural comfort. In-situ and laboratory questionnaire surveys were conducted to measure SdI in various spatial forms of metro commercial spaces. The significantly influencing factors were studied using Pearson correlation and linearity analysis. The results show that acoustic parameters such as sound levels, sound source, and reverberation time (RT) are not key factors in the evaluation of SdI, but the variables of spatial form and sound absorptions are. Based on the findings of analyzing the key influencing factors, prediction models for quantifying SdI were developed. The results show that there is no holistic approach to quantifying SdI for all kinds of metro commercial space, due to the distinct spatial form of each type of the spaces.