Abstract: A modal analysis method and apparatus for acoustically determining dynamic vibration characteristics of a structure, including natural frequencies, mode shapes and damping factors, is based on a Multiple-Input-Single-Output (MISO) model. The method and apparatus involve generation of an acoustic excitation signal toward n spatially distributed locations associated with the structure while the latter is held to allow vibration thereof, one of the locations being chosen as a reference location. A series of microphones are disposed at the locations to produce m complementary sets of n input acoustic pressure-related electrical signals, one of these being chosen as a reference signal associated with the reference location. A Fourier analysis is performed on the sets of input acoustic pressure-related electrical signals to provide corresponding sets of correlated input acoustic pressure-related data in the frequency domain including reference data associated with the reference signal.