Measuring the quieter side of water vehicles
The boom and din of high speed water-boats can be heard from vast distances. While some might enjoy the crashing sound, they nevertheless are noise pollutants, disrupting both marine life and the quality of life for others. Investigating means by which on-board measurements can be taken to reduce noise levels was of primary concern for a consortium of researchers. Their goal was to develop a single, robust method in which compliance to the directives relating to sound levels could be certified. In doing so, they developed a test prototype called SoundBoom. The device allows for the prediction of a vessel's compliancy as it passes by. The measurements are taken on board by an on-board boom. This boom is an extended pole having a power supply and amplifier within the boom handle. The microphone is wind-shield fitted for more accurate readings and the whole thing is connected to a standard laptop computer via a USB device. The project investigated five sound measurements taken at selected positions on the boat which are analysed in real-time. One of the major developments of the research was its predictive algorithm. This two-part algorithm provides both a predictive measurement of the sound levels whilst the second part provides an empirical method for exhaust noise levels. Another achievement was to identify key parameters of boat-noise. A third was in identifying suitable measures and equipment needed to measure noise levels. Further activity in the project will now look at getting the method accepted for certification.
