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This paper presents an experimental method for analyzing the acoustical characteristics of enclosed cavities with respect to multiple coherent noise sources. The method is based on the application of a Multiple Input/Two Output frequency domain model. The model outputs are the sound pressure signals from two closely spaced microphones while the model inputs are characteristics from the candidate noise sources. The emphasis of this paper is on the implementation and interpretation of the method results in a simulated laboratory environment. First, the theory behind this method is briefly reviewed. Next, the method is applied to a three dimensional rectangular cavity with two coherent cavity excitation sources.

This paper presents an experimental method to analyze the acoustical characteristics of enclosures with respect to the noise sources. The method is based on the application of a multiple input/two output frequency domain model. Characterestic signals from each of the candidate noise sources represent the inputs, while the sound pressure signals from two closely spaced microphones are the outputs. By using a finite difference approximation with microphone signals the specific acoustic impedance and acoustic particle acceleration are estimated at an array of positions throughout the cavity. The impedance is used to separate the sound pressure into its progressive and standing wave components. The standing wave component is further described in a normal modes fashion by application of structural modal analysis curve fitting routines to the acoustic particle accelerance frequency response functions measured throughout the cavity.