In this paper, the acoustic environment in a vehicle cabin under the influence of highfrequencies aerodynamic sources has been studied. Some panels on the windshield, the roof, the doors, the front pillars, and the floor of a vehicle simulated as input source of noise when the car is moving at high speed, i.e. 112 km/h. The status of vehicle cabin in each of these modes has been studied and com...

Abstract In order to investigate the possibility of using acoustic cavitation noise generated by ultrasonic horns as an measurement signal, its directional characteristics, autocorrelation and frequency characteristics are investigated with a hydrophone schlieren visualization. addition, parabolic mirror is used shape spherical into plane wave. As result, it found that consists shockwave pulse ...

(1996) Vibration modes and acoustic noise in a four-phase switched reluctance motor. Abstruct-Acoustic noise in the switched reluctance motor (SRM) is caused primarily by the deformation of the stator lamination stack. Acoustic noise is most severe when the periodic excitation of the SRM phases excites a natural vibration mode of the stack. The natural vibration modes and frequencies of a four-...

Wireless-VoIP communications introduce perceptual degradations that are not present with traditional VoIP communications. This paper investigates the effects of such degradations on the performance of three state-of-the-art standard objective quality measurement algorithms—PESQ, P.563, and an “extended” E-model. The comparative study suggests that measurement performance is significantly affect...

Introduction of new communication standards makes specifications given to RF surface and bulk acoustic wave (SAW/BAW) devices tougher and tougher. For example, futher improvement of the device linearity is demanded without increasing the device size. Nevertheless, it is still unclear where and how the non-linearity occurs. For finding origin(s) of the very weak non-linearity, its measurement sy...

This paper introduces a new method of pulsed magnetic acoustic emission (MAE) for stress detection and material characterisation and investigates the viability of implementing an acoustic emission sensor array for enhanced location information and noise suppression. Pulsed excitation can provide wide spectral components for non-destructive evaluation and material characterisation and lead to gr...