Hot topics in engineering acoustics: New acoustic products and processes

Abstract

Engineering acoustics is the study of products and processes that are directly related to sound or that use sound as a tool. This talk discusses some of the exciting advances in acoustic products and processes in the last few years. New acoustic products which are discussed include solid-state acoustic sensors and actuators, improved hearing aids, and thermoacoustic refrigerators and engines. Solid-state acoustic transducers are miniature sound sensors and sources which are made using silicon (or another semiconductor) and fabricated using VLSI technology. Such transducers offer the opportunity for mass production and extreme miniaturization. Hearing aids are devices intended to present amplified sound to hearing impaired individuals. Recent advances in their signal processing have made dramatic improvements in the quality of sound being presented to the wearer. Thermoacoustic refrigerators and engines are devices which use sound waves to achieve ‘‘pumping.’’ They offer the advantages of making it possible to eliminate moving parts, and to eliminate use of environmentally unfriendly chemicals. There have also been exciting advances in acoustic processes in recent years. This section of the talk will focus on ultrasonic machining, in which ultrasonic vibration of a machine tool is used to achieve precise and relatively rapid material removal.