Blocked pressure based Transfer Path Analysis (TPA) method to diagnose airborne sound transfer through building partitions

Abstract

Airborne sound transmission through building elements or the sound insulation of the building element is usually rated by its Sound Reduction Index (SRI) or the Sound Transmission Class (STC). SRI/STC quantifies the overall sound transfer but gives no information about how the transfer takes place and what are the contributions of different sound transfer paths involved. Such problems are fairly common to the vehicle acoustics industry and are generally tackled by TPA techniques. The paper formulates an in-situ Airborne TPA technique to quantify the contributions of different sound transfer paths to the transmitted pressure. The airborne source is characterized by its blocked pressure and its direct measurement is discussed. Results are presented for dual leaf partitions excited by an airborne source. The method has shown to be significantly faster than the Blocked force based TPA method which relies on inverse measurement methods. The accuracy of the method is closely related to the wavelength of incident airborne waves.