Experimental study on vibration response of wooden house façade to low-frequency outdoor sound

Generally wooden house has low sound insulation performance for low-frequency outdoor noise due to the lightweight façade wall system. Moreover, the sound insulation performance is caused by the vibration responses of window and wall systems, that are strongly coupled with normal modes in a room. In order to clarify the complicated phenomena, field measurements of vibration characteristics are conducted for a test house with Japanese traditional wooden structure, under the cases with single/double window systems. As outdoor sound source, low-frequency band noise from 25 Hz to 160 Hz is emitted from a subwoofer, and vibration acceleration is measured on each element, such as window glazing, interior walls, floor, and ceiling. From the analysis of measured vibration transfer functions and indoor sound pressure distribution, the vibration characteristics of the whole coupled system are discussed, especially on the effect of different window systems.