Underwater Noise Radiated from Ships

Underwater radiated noise from modern commercial ships.

Underwater radiated noise measurements for seven types of modern commercial ships during normal operating conditions are presented. Calibrated acoustic data (<1000 Hz) from an autonomous seafloor-mounted acoustic recorder were combined with ship passage information from the Automatic Identification System. This approach allowed for detailed measurements (i.e., source level, sound exposure level...

Isolator Internal Resonance and Radiated Noise from Ships

Reducing the radiated noise from ships is becoming increasingly important as ship -builders aim to reduce the disturbance to marine life, passengers and crew. A major contributor is on-board machinery which typically radiates noise to the water column from both structure-borne and air-borne transmission paths. Problematic machinery is often decoupled from the hull by supporting it on resilient ...

Radiated Noise Measurement of Ships Based on Stochastic Resonance

The radiated noise of ships involves strong low-frequency line spectrum, which is greatly related with the working states of auxiliary equipment and the rotation of propeller, and then regarded as the important basis in feature extraction of ships. Moreover, the stochastic resonance has special advantages in the extraction of weak signal. Aiming at the multi-frequency components in radiated noi...

Underwater Noise from Ships – Causes and General Approaches to Noise Control

Awareness of underwater noise generated from shipping is rising due to environmental concerns in sensitive areas with protected animal species as well as for the world’s oceans as a whole. Individuals interested in underwater noise have attempted to better understand the problem by performing measurements of vessel noise either by direct measurement or by recording sound levels in different oce...

Radiated Noise from an Externally Blown Flap