Engineering acoustics attempts to utilize contemporary developments in many areas of science, technology, and analysis to produce acoustical systems and products which address existing needs or create new opportunities. Topics in engineering acoustics become ``hot'' when there is a convergence which facilitates a ``quantum leap'' in some particular application area. Fusion of new sensor technologies, microprocessors, signal processing, and electronic data communication has produced new options in condition-based monitoring of machinery and industrial processes. Advances in the speed and reduction of cost in A--D and D--A converters, coupled with high memory density, has permitted the development of acoustic time reversal mirrors which could have application to ultrasonic nondestructive evaluation of materials. Computing power, new inversion algorithms, and novel transducers have led to the commercialization of resonant ultrasound spectroscopy which can determine the complete set of elastic moduli for materials with sample sizes which can be less than 1 mg. The availability of fast, accurate one-dimensional computer-based acoustic modeling tools and new research results in studies of the transfer to heat from acoustically oscillating fluids to solid surfaces are providing a new foundation to design and optimize the next generation of thermoacoustic engines and refrigerators.