Re-evaluation acoustic quality in lecture halls using G and C50: University of Sharjah Case Study

Abstract

In our previous studies, we focused on the common approach of measuring Reverberation Time (RT) for assessing acoustic quality in various types of lecture halls at the University of Sharjah (United Arab Emirates). The absorbing surfaces at the lecture halls at the University of Sharjah are limited to one surface (hanging ceiling), which has been shown in the literature to affect the accuracy in the description of the acoustic response as a result of the introduced uncertainty in the measured reverberation times. Because of these reasons, it has been highlighted in the literature that RT is considered not a good predictor of acoustic quality, namely speech intelligibility, in the lecture halls. Therefore, additional acoustic parameters need to be measured of calculated to accurately predict the acoustic response in lecture halls, especially speech intelligibility during activities that takes place within the lecture hall. The focus of our current research is to extend our precious work on RT to calculate additional acoustic parameters, namely the acoustic strength, G, and the speech clarity, C. Our goal is to investigate the practical use of G and C to describe acoustic response in the examined lecture halls. In addition to special variations with frequency, we will examine the effects source position, room dimensions at different locations within the lecture hall. The measurements were conducted in the same lecture halls under the same conditions including the acoustic absorbers and sound diffusers, which have shown to influence measured acoustic parameters. The results were compared to standards for the purpose of providing recommendations for range of acoustic parameters to support adequate speech communication during various teaching and learning activities in lecture halls.