it is accepted that noise pollution has a major impact on health, such as physical, physiological, psychological and performance related effects, all over the world. this study aims to evaluate noise pollution in four urban parks located in sanandaj city, iran and to zone it in gis environment. sound pressure level (spl) and maximum sound level (lmax) were measured at 45 points (each point was ...

Premature combustion that affects outputs, thermal efficiencies and lifetimes of internal combustion engine is called “knock effect”. However knock signal detection based on acoustic sensor is a challenging task due to existing of noise in the same frequency spectrum. Experimental results revealed that vibration signals, generated from knock, has certain frequencies related to vibration resonan...

original article   introduction: a practical solution which is sometimes efficient for noise control in the receiver locations is to enclose workers in an acoustic cabin. accordingly, prediction of the noise insulation performance is regarded as an important aspect of the design a personnel cabin. this study empirically aims to design an acoustic cabin using sandwich panels in a typical metal i...

Rotating cylinders have wide applications in different areas, especially the aerodynamic area. However, the acoustic behaviors of these components have not been widely studied. The generating noise from a spinning cylinder is mainly due to the detached vortices from the leeward of the body. In this study, the large eddy simulation technique is used to simulate the flow field over a three-dimens...

excessive exposure to noise can lead to noise-induced hearing loss. otoacoustic emissions affect the microscopic biomechanical activities of healthy outer hair cells. the present study aimed at assessing the influence of various sound pressure levels on distortion product otoacoustic emissions (dpoaes) in rats. to this end, 27 adult male rats with an age range of 3 to 4 months and a weight of 2...

In ultrasonic nondestructive evaluation (NDE), flaw characterization is inhibited by the effects of the measurement system and by acoustic noise due to non-flaw related scattering of the sound. The Wiener filter can be formulated to optimally remove the effects of the measurement system and suppress the noise; however, prior information must be available abeut the neise and flaw distributions, ...

The acoustics of isolated vowels, e.g. of /a/, have in many studies been linked to pathological voice types, such as tracheoesophageal (TE) voice. To study the possibilities of objective and automatic classification of pathological TE voice types, the acoustic features of /a/ were quantified and subsequently classified using a suit of machine learning technologies. Best classification was achie...

In this paper, it is described that acoustic intensity of a rail load machine was measured for decreasing the operating noise. To locate exactly the noise sources on the machine, Operational modal measurement and analysis was performed. Comparing the results of analysis the both sets of data measured, the main components of emission noise were determined. Further, improving design of the machin...