Assessment of Acoustic Properties of Lecture Theatres in Ladoke Akintola University of Technology, Ogbomoso, Nigeria

Abstract

Acoustic design is an important consideration in the design of lecture theaters (LTs); it has a significant impact on communication between students and instructors, their hearing comfort levels, lecture outputs and their overall performance. However, despite the significant role acoustic design plays in LTs, it has not received a significant attention both in design and literature in the developing countries especially Nigeria. This study is hence aimed at assessing the acoustic properties of lecture theaters in Ladoke Akintola University of Technology (LAUTECH) Ogbomoso with a view to establishing the design requirements for effective acoustic comfort in lecture theatres in Nigeria. Seven (58.33%) lecture theaters were randomly selected out of a total of 12 available in the study area and were objectively analysed. Shape of the lecture theaters, wall, floor, ceiling and furniture surface finishes were physically observed and their sound absorbing coefficients were evaluated and compared with data obtained from the Bureau of standards for the sound absorption coefficients, ISO 354 and literature. The total surface absorption coefficients of materials and surface area were used to calculate the Reverberation Time (RT) using Wallace Sabine model and results was compared with RT standard of between 0.5 and 1.0s recommended by scholars Odoh and Urenyang for LTs in Nigeria. The study observed that walls, floor and ceiling surfaces were treated with materials of low sound absorbing coefficients while only the ceilings were treated with high coefficient materials, the effect was observed in the RT values obtained. It was observed that only 3 (42.86%) LTs have their RTs within the recommended standards and hence are capable of providing good acoustic comfort for users while 4 (57.14%) LTs have excessive RT implying likely acoustic discomfort. The study recommended that materials with high sound absorbing coefficients be used for building component finishes and acoustic decisions should be taken right from design inception stage.