Sound sources can be localized and analysed using phased microphone arrays.Beamforming is a method for processing microphone array data to produce images that represent the distribution of the acoustic source strength.It is an imaging technique that applies to continuous or discrete source distribution.A microphone array can be designed to be more sensitive to the sound coming from one or more ...

Equipment for use in potentially explosive atmosphere is subject to particular requirements on safety and quality as determined by a number of Standards. For use in Europe, such equipment needs to conform to the EC directive 94/9/EC, also called “ATEX Directive”. The conformity must be certified by a socalled ATEX Certificate. In the frame of the EC-funded research project „Corrosion testing of...

Surface waves are commonly used for vibration-based nondestructive testing for infrastructure. Spectral Analysis of Surface Waves (SASW) has been used to detect subsurface properties for geologic inspections. Recently, efforts were made to scale down these subsurface detection approaches to see how they perform on small-scale structures such as concrete slabs and pavements. Additional efforts h...

This paper presents a hands-free speech recognition method based on HMM composition and separation for speech contaminated not only by additive noise but also by an acoustic transfer function. The method realizes an improved user interface such that a user is not encumbered by microphone equipment in noisy and reverberant environments. The use of HMM composition has already been proposed for co...

The monopole-source solution was used to calculate the three-dimensional complex acoustic pressure field for one-dimensional focused rectangular apertures in a medium having homogeneous acoustic and thermal properties. For each of six frequencies (1, 3, 5, 7, 9 and 12 MHz) and three focuses (f/1, f/2 and f/4), 33 rectangular aperture cases were investigated, for a total of 594 cases. For these ...

biophysical profile (bpp) test is the most commonly used antenatal test of fetal well-being. purpose of this study is determining the influence of acoustic stimulation (as) on bpp testing time. about 55 pregnant women at 35 to 42 weeks who referred to department of obstetric & gynecology at university of medical sciences, tabriz, iran, were selected randomly. we used abdominal ultrasound guidan...

We describe a simple and inexpensive method for monitoring nasal air flow resistance using measurement of the small-signal acoustic input impedance of the nasal passage, similar to the audiological measurement of ear drum compliance with acoustic tympanometry. The method requires generation of a fixed sinusoidal volume-velocity stimulus using ear-bud speakers, and an electret microphone to moni...

This paper describes a prediction method for the contribution of the main onboard machinery to the underwater acoustic signature of steel surface vessels that can be used during the design stage. There are two reasons for the development of this method. Firstly, a small acoustic signature is important for naval and research vessels, due to operational requirements concerning detection and inter...

Geoacoustic inversion requires a generic knowledge of the frequency-dependence of compressional wave properties in marine sediments, the nature of which is still under debate. The use of in situ probes to measure sediment acoustic properties introduces a number of experimental difficulties that must be overcome. To this end, a series of wellconstrained in situ acoustic transmission experiments ...

This paper addresses the problem of summer branch drop (SBD) in urban forests, namely through detecting causes this unpredictable event, aiming at preventing and increasing control phenomenon, while using most recent methodologies to detect wood deterioration, visual tree assessment (VTA), drilling resistance, acoustic tomography, an isolated associated way. The study considers events cities Ar...