Twelfth International Congress on Sound and Vibration TOTAL TRANSMISSION LOSS OF FINITE SINGLE AND DOUBLE PANELS USING STATISTICAL ENERGY ANALYSIS Prof. Dr. M. A. Kenawy (Ain-Shams University, Cairo-Egypt) Dr. M. Y. Elaidy (Acoustics dep., National Institute of Standard NIS, Cairo-Egypt) Mohammed Abd-Elbasseer (Acoustics dep., NIS, Cairo-Egypt) Abstract Statistical Energy Analysis (SEA) is statistical in that frequencies of resonance for each subsystem are assumed to be uniformly distributed in frequency within each of the frequency bands used in the analysis since it is assumed that energy resides only in resonance modes, the total energy in each subsystem is the sum of the energies in the modes. This energy is assumed to be equally among the modes in each subsystem and analysis band by definition, subsystems are structural or acoustical entities that have modes, which are similar nature and have equal modal energies. Different subsystems typically have different modal energies. SEA permits calculations of the energy flow between connected resonant structures, such as panels, beams, etc., and between panels and the reverberant sound field in an enclosure. Also SEA is used to predict the response of dynamic system to external power input. A system will refer to the entire complement of coupled structures and acoustic spaces under considerations. The system is then divided into subsystems, which consists of collection of similar resonant modes within a structure or acoustic space. Two important phenomena in the statistical energy analysis are the resonant and non- resonant vibrations in a panel. When a sound wave impinges on a panel, the panel forced to vibrate. Such forced vibrations are called non-resonant vibrations. The non- resonant vibrations are reflected at the boundaries and standing waves are formed. These standing waves are called resonant vibrations. In the analysis it is resumed that the non-resonant and resonant vibration may be superimposed. In order to obtain a precise total transmission loss. This paper presents a detailed TL r and TL nr and also a simple mathematical relation of calculating the total transmission loss for finite single and double panels instead of the calculating diagram, which is usually presented in other papers.