Measurement and analysis of teaching and background noise level in classrooms of Chinese elementary schools

The background noise and teacher's teaching speech levels were measured in classrooms of Chinese elementary schools during class time in two conditions of using or without using sound reinforcement system (SRS). The ranges, mean values and standard deviations of the measurement data are reported and analyzed. It is found that in the condition of without using SRS, the relationship between the background and teaching levels satisfies the lambert effect quite well, while in the other condition of using SRS, this effect does not hold. Differences of background noise level and thus teaching level seem to be found between different courses but not be found between genders of the teachers. Finally, the background noise level is observed generally higher in classrooms of junior grades than the senior, and so is the teaching level.