Experimental and Numerical Investigations of Acoustic Variations in a Classroom Environment

The acoustic behaviour of a classroom is vital for an effective teaching-learning process. The present work aims to experimentally determine the acoustic performance of a typical classroom. The full-scale experiment was conducted at the Seminar Hall, the Department of Applied Mechanics, MNNIT Allahabad, Prayagraj, using a method with limited resource requirements. The Seminar Hall was divided into four planes by threads, and the sound pressure level (SPL) was measured at 30 coordinates in each plane for the specified sound source location. Data were collected from three different sound source locations. The study revealed that the sound source location and frequency significantly influence the sound pressure levels in the classroom, impacting its acoustic performance. The broader implications of interior materials, such as wall material and the position of elements like the teaching board, door, and podium, are highlighted as critical considerations for future classroom acoustic optimization. Furthermore, a numerical model was developed to predict the variation in the SPL with change in the sound source locations and frequencies. The collected data validated with the finite element (FE) model. The verification experiments for the modeling results were performed for each plane. The results of the FE model and experiments were found consistent across all four planes of the seminar hall and the various sound source locations.