One of the many exciting recent advances in active structural acoustic control has been the introduction of intelligent material systems. Intelligent material systems are hybrid “composite” systems of highly integrated sensor, actuator and adaptive/learning control systems within the structural element or material. One of the interesting and useful transduction techniques for structural acoustic control is active control of the mechanical properties of adaptive materials. Materials that exhibit this adaptive capability include shape memory alloys and polymers, electrorheological fluids, and ferroelectric materials. This presentation will begin with a brief introduction to the adaptive materials mentioned above and then proceed to demonstrate the utility of these unique materials. In particular, experimental and analytical results will be presented for a material system that combines the adaptability of the Young's modulus with the effect of induced strain actuation, namely, shape memory alloy hybrid composites. Results for an active control scheme recently developed and termed adaptive alternate resonance tuning will be highlighted.One of the many exciting recent advances in active structural acoustic control has been the introduction of intelligent material systems. Intelligent material systems are hybrid “composite” systems of highly integrated sensor, actuator and adaptive/learning control systems within the structural element or material. One of the interesting and useful transduction techniques for structural acoustic control is active control of the mechanical properties of adaptive materials. Materials that exhibit this adaptive capability include shape memory alloys and polymers, electrorheological fluids, and ferroelectric materials. This presentation will begin with a brief introduction to the adaptive materials mentioned above and then proceed to demonstrate the utility of these unique materials. In particular, experimental and analytical results will be presented for a material system that combines the adaptability of the Young's modulus with the effect of induced strain actuation, namely, shape memory alloy hybrid compo...