A fiber-reinforced composite part comprises structural fiber strands and linear electromagnetic-to-acoustic transducers embedded in a polymeric matrix. When these internal transducers are activated in sequence, the propagating acoustic waves are detected by an array of external acoustic-to-electric transducers acoustically coupled to external surfaces of the part. These external transducers convert impinging acoustic waves into electrical signals that carry information concerning acoustic wave amplitudes and phase shifts relative to the excitation of the internal transducers. The electrical signals are processed by a computer which is programmed to determine the location and orientation of each internal transducer and ultimately the structural integrity of the composition.