APPLICATION OF IMPULSE METHOD TO IN SITU MEASUREMENT OF SOUND REFLECTION

This paper presents an experimental study on the reflection of sound pulse from reflected ceiling and walls in a hall by using an electric spark source. The ceiling consists of plywood ribs and wire meshes and the reflected walls are concrete sticked with plywood facing. The transfer functions of reflected sound, waves were calculated from the experimental incident and reflected sound pulses by use of FFT. The effects of the pulse series length on the transfer function are discussed. The changes of the transfer functions of reflected sound waves were analysed in the case of absorption structure with ribs. The transfer functions of reflected sound wave for 0, 30, 60 degree incident angles are given.