Research on the Background Noise of Ordinary Classrooms

Abstract

The level of background noise is one of the key factors to influence the classroom acoustic; for students study can be disturbed in noisy environment, 17 classrooms are chosen including 8 old classrooms and 9 newly build classrooms of a college in Beijing. Sound pressure level and noise criteria were calculated. The result of the average background noise in new classroom is 43.1 dB(A) and 45 dB(A) in old classroom. The noise in old and new classrooms exceeds the standards in different levels. The value of the NC of two old classrooms is higher than the limited level and that of others meets the requirements of the standards. Classroom indoor background noise is mainly affected by the indoor air-conditioning system, the surrounding classroom situation, and the outdoor environmental noise. The further discussion is made on the results in the paper.