Editorial

Noise and vibration have long been considered as pollutants of the environment with adverse effects on humans and physical being. There is continued effort within the scientific and technological research community, on the one hand, to study and establish the characteristic nature of such phenomena from viewpoints of source, environment and their associated effects, and on the other hand to devise approaches for control of such phenomena. The investigations have ranged from theoretical to experimental and practical studies. Low frequency noise and vibration have posed specific challenges in these studies, largely due to limitations in response characteristics of sensing and actuation technologies, to be able to capture important data and to deliver necessary signal contents. Despite the current advances made in smart materials to address these challenges there is a great deal of scope yet to explore.

This issue contains eight research articles falling under areas of control, condition monitoring and health effects of low frequency noise. Among these four articles, namely Rakhshan et al., Xiao et al., Liu et al. and Sun et al. present approaches for control of noise and vibration; Rakhshan et al. introduce the concept of WAVENET for active noise control, making use of feedforward neural network with a wavelet function for the network activation, Xiao et al. present non-linear analyses of a semi-active vibration isolation system using a revised Bingham model of magneto-rheological (MR) damper, Liu et al. present piezoelectric optimal control mechanism for nonlinear vibration control of beams, and Sun et al. present an approach with use of artificial muscle to dampen seat vibrations in crawler type construction vehicles. Abad et al. and by Ferrando Chacon et al. focus on condition monitoring, where the former introduce a method based on wavelet transform and support vector machine and the latter focus on acoustic emission as a means of health diagnosis. Noise emission from wind turbines and their health effects have become a focus of many studies in recent years. The remaining two articles in this issue by Tonin et al. and Abbasi et al. are related to health effects of noise from wind turbine farms, where Tonin et al. discuss the effects of infrasound from wind farms and Abbasi et al. look at the health effects on a localised scale among workers of a wind farm.