Abstract Context Synchronised acoustic recorders can be used as a non-invasive tool to detect and localise sounds of interest, including vocal wildlife anthropogenic sounds. Due the high cost commercial synchronised recorders, localisation has typically been restricted small or well funded surveys. Recently, low-cost have developed, but until now their efficacy not compared with higher specific...

The average particle size and its distribution are undoubtedly major characteristics of a powder, and the average particle size occurs in all correlations related to the powder behaviour in, e.g., packed, moving or fluidized beds, in pneumatic conveying and in dust filtration. When traditional sieving can no longer be used for smaller particles, instrumental techniques, i.e. particle size analy...

An efficient finite volume approach has been used to develop a three dimensional Helmholtz acoustic solver for complex geometries. This acoustic solver was utilized to obtain characteristic mode shapes and frequencies of a baffled combustion chamber. An experimental setup, including stationary and moving sensors, has also been used to measure these quantities for the same model combustion chamb...

Phased array ultrasonic testing technology is of flexible, reliable, efficient and suitable for special equipment welds non-destructive testing. Sectorial scan angle range was investigated in this paper for phased array ultrasonic oblique incident pulse shear wave testing of special equipment welds made in low carbon steel. The theoretical calculation of ultrasound wave energy transmission coef...

This paper explores use of synergistically-integrated systems of microphone arrays and neural networks for robust speech recognition in variable acoustic environments, where the user must not be encumbered by microphone equipment. Existing speech recognizers work best for "high-quality close-talking speech." Performance of these recognizers is typically degraded by environmental interference an...

Residual echo arises in hands–free telephony equipment due to insufficient echo canceler convergence, but can be suppressed using a postfilter. The residual echo power spectral density is the most crucial control parameter for both frequency–domain acoustic echo cancellation and combined residual echo and noise postfiltering. In this contribution we present and compare residual echo power spect...

This paper proposes new partial discharge (PD) pattern recognition based on the Hilbert–Huang Transform (HHT). First, five types of defect models are well-designed on the base of investigation of many power equipment failures, and a commercial acoustic emission (AE) sensor measures the acoustic signal caused by the PD phenomenon. Next, the HHT can represent instantaneous frequency components th...

The modern underwater acoustic equipment, like multibeam sonar, is able to provide the data which allow for unambiguous localization and also 3 visualisation of targets of different kinds, including wrecks, mines and other submerged objects. The large amount of information that seems to be useful for this purpose, could also be extracted from side-scan sonar data, which has been collected over ...