Sound reflection patterns in the classroom of slanted floor

Speech intelligibility (SI) is the measurement of understanding the speech sound by the individuals. In the classroom, modern engineering acoustics has been discussing about the effect of SI such as the academic performance and health of students. Sound reflection in the classroom is one of the factors that affect SI and it is characterized into two types which are early reflections and late reflections. The purpose of this research was to obtain the sound reflection pattern in two classrooms with slanted floor of about the same size. It was done by capturing the sound signal at 12 measurement points in the classroom using Real Wave Analyzer (RWA) and a Smartphone. The sound signals were converted into Power Spectral Density (PSD) using Matlab to analyse the sound reflection patterns. This research also aims to observe the difference of PSD results from which the sound signals were acquired from RWA and Smartphone. It has been found that, the nearer the distance of the ground to ceiling results a higher PSD in both room sample at 1000Hz. Besides, using Smartphone results a higher PSD compared to using RWA at 500Hz. In conclusion, the nearer distance of ground to ceiling in a slanted floor classroom results a higher PSD at 1000Hz