The half-day course will introduce attendees to Underwater Radiated Noise (URN) from ships. There will be a brief introduction to general acoustics and underwater sound metrics. The course will address the transmission of shipboard sound and vibration to URN and principal methods for reduction for each of the sources and paths. Treatments used outside the hull will be discussed, including flow improvements, quiet propellers, and air bubble systems. Engineered treatments used within the hull will be discussed, including vibration isolation mounts, equipment enclosures, hull damping, and plating insulation. Operational measures for reduction of URN will also be addressed. Example treatments and outcomes will be given. Measurement and quantification of URN will also be discussed including: instrumentation; hydrophones, arrangements of at sea measurement systems. Finally, the course will discuss relevant standards for measurement of vessel URN from ANSI, ASA, ISO and the Class Societies.

Who Should Attend
This course is intended for noise-control professionals seeking to understand how ships generate underwater radiated noise (URN) and how noise-control principles apply. It will also benefit marine-industry professionals, including vessel engineering staff, chief engineers, and port engineers who want to better understand shipboard noise generation and mitigation. Finally, regulators preparing for potential future limits on vessel URN will also find the course valuable.

Michael Bahtiarian, INCE Bd. Cert, INCE Fellow — Author / Presenter
Mr. Bahtiarian is a board-certified noise control engineer by INCE-USA with over 25 years of experience in designing and testing quiet ships. These have included the first quiet research vessels in the United States; the NOAA Fishery Research Vessels (FRVs), U.S. Navy AGOR-24 Class oceanographic research vessels (R/V Neil Armstrong and R/V Sally Ride), and the University of Delaware R/V SHARP. Mr. Bahtiarian was the technical facilitator for the Underwater Vessel Noise Reduction Targets (UVNRT) initiative supported and coordinated by Transport Canada to develop underwater radiated noise limits for individual ships. He was also the chair of two different standard committees that produced the first two standards for the measurement of underwater noise from ships; ANSI/ASA S12.64 and ISO-17208-1. Mr. Bahtiarian is a principal with Acentech, Inc., a multi-disciplinary acoustics, noise, vibration and technology consulting firm in Cambridge, Massachusetts. He is the 2018 Distinguished Noise Control Engineer, former president, and fellow of the Institute of Noise Control Engineering (INCE-USA).