Design of Anechoic Room for Engine Noise Test and Its Performance

An anechoic room for engine noise test was constructed. In constructing it, the sound absorbing wall with its supporting structures was carefully designed because their strong influence on the performance of the anechoic room. The back ground noise, the inverse square law and the mean absorption coefficient of this room were examined in detail. From these experimental results, it was confirmed that this anechoic room showed the sufficient characteristics for the experimental researches on noise generation from running engines.