Changes in the characteristics of the cough sound may refer to some specific pathological processes and their evolution. In this pilot study we analyzed voluntary cough sound properties in subjects with asthma bronchiale (AB) and chronic obstructive pulmonary disease (COPD) and discriminated them from the control cough sound in healthy subjects. The wavelet transform was used due to a nonstatio...

ABSTRACT Current methods for the determination of sound power such as the ISO 3740 series do not have a direct traceability to a primary standard. The different methods are regarded as equal, but they do give results with systematic differences. One task of the European project “EMRP JRP SIB 56 SoundPwr” has been to develop and investigate traceable and consistent methods for sound power measur...

original article   introduction: wind-turbine noise emission and its environmental impact are considerable issues nowadays. considering the importance of the issue, the purpose of this study was to prepare noise map and wind turbines sound characteristics on the largest wind farm of iran. method: this study was carried out in two phases:1) in order to prepare the daytime sound level (ld) noise ...

We present results from large-scale numerical simulations of a first order thermal phase transition in the early Universe, in order to explore the shape of the acoustic gravitational wave and the velocity power spectra. We compare the results with the predictions of the recently proposed sound shell model. For the gravitational wave power spectrum, we find that the predicted k−3 behavior, where...

A comprehensive finite element methodology is developed to predict the compressible flow performance of a non-symmetric 7-blade axial flow fan, and to quantify the source strength and sound pressure levels at any location in the system. The acoustic and flow performances of the fan are predicted simultaneously using a computational aero-acoustic technique combining transient flow analysis and n...

GLOSSARY OF SYMBOLS r distance from pressure sample point to center of piston a radius of circular radiator R_ dc resistance of driver voice coil ao radius of diaphragm, = _/SD/_r E surface area ay radius of circular vent, = 5/Sv/_r SD effective projected surface area of driver diaphragm c velocity of sound in air, = 343 m/s Sv cross-sectional area of vent ein voltage applied to driver input SP...