Have you heard the latest from the Acoustical Society?

Although we have long wanted to see the Mormon Temple, we are sorry to tell our readers we will be unable to meet them in Salt Lake City next week for the annual meeting of the Acoustical Society of America (ASA). It sounds — ha! ha! — like an interesting affair, with more than 650 papers scheduled for presentation on such topics as “how dinosaurs heard their world”, “catching killer whales in the act”, “the science of jazz and yodeling”, and, most important of all for our purposes, “preventing terrorist activity in ports and harbors.”

The proof of concept in question, presented by professor Karim Sabra of the Scripps Institution of Oceanography, imagines an “acoustic tripwire” surveillance system for detecting intruders in harbor entrances. The technique is designed for the shallow-water choke points of harbor entrances less than twenty meters deep, which often have high levels of ambient noise. In a similar and related vein, Peter Stein of New Hampshire-based Science Solutions will present his swimmer detection sonar network (SDSN), designed to be a cost-effective method to protect a large area from swimmers intending to carry out terrorist activities. Now available commercially, the in-water system consists of sets of sonar dishes and signal-processing algorithms for automated detection, tracking, and classification of moving objects such as swimmers.