An approach to estimating sound absorption increment via equivalent substitution

Abstract Excessive reverberation time in classrooms can impair speech intelligibility, reduce lecture quality, and hinder students' listening efficiency. Implementing precise and scientifically rigorous acoustic modifications is crucial for these classrooms. Calculations and simulations based on Sabine's equation or acoustic modeling software require precise absorption coefficients of the finishing materials, making it challenging to determine the required sound absorption increment. This paper proposes a method of equivalent substitution measurement: A non-destructive control group is established for acoustic experimentation, allowing for the precise calculation of the sound absorption increment required to achieve the target reverberation time. This approach provides scientific, rigorous, and customized reverberation time recommendations particularly for complexly shaped spaces from small to medium size to optimize the acoustic environment.