Clock-Offset and Microphone Gain Mismatch Invariant Beamforming

The use of wireless acoustic sensor networks (WASNs) has received increased attention over the last decade. The advantages of WASNs over stand-alone multi-microphone devices are that the microphone array is not anymore limited by the dimensions of a single device, and that microphones can be placed at arbitrary locations. One of the...

Industrial sound source localization using microphone arrays under difficult meteorological conditions

Source localization using microphone arrays has now become common practice for many applications. Their application for long term monitoring of industrial noise nevertheless remains uncommon. Hence, in 2016 we deployed four microphone arrays near a large industrial area for a period of 12 months and explored the challenges involved. The...

Fusion of multiple microphone array data for localizing sound sources in an industrial area

Direct measurements of acoustic damping and sound amplification in corrugated pipes with flow

The flow-induced pulsations in corrugated pipes result from a feedback loop between an acoustic resonator and the noise amplification at each shear layer in the axisymmetric cavities forming the corrugations. The quality factor of the resonator is determined by the reflection coefficients at the ends of the corrugated pipe and by the damping in...

Amplitude, phase, location and orientation calibration of an acoustic vector sensor array, part I: Theory

An acoustic vector sensor array consists of multiple sound pressure microphones and particle velocity sensors. A pressure microphone usually has an omni-directional response, yet a particle velocity sensor is directional. Currently, acoustic vector sensor arrays are under investigation for far field source localization and visualization. One of...

Amplitude, phase, location and orientation calibration of an acoustic vector sensor array, part II: Experiments

An acoustic vector sensor array consists of multiple sound pressure microphones and particle velocity sensors. A pressure microphone usually has an omni-directional response, yet a particle velocity sensor is directional and usually has a response pattern as a figure of eight. Currently, acoustic vector sensor arrays are under investigation for...

The Majority Wins: A Method for Combining Speaker Diarization Systems

In this paper we present a method for combining multiple diarization systems into one single system by applying a majority voting scheme. The voting scheme selects the best segmentation purely on basis of the output of each system. On our development set of NIST Rich Transcription evaluation meetings the voting method improves our system on all...

Low sound level source path contribution on a HVAC

For compliance test purposes, the noise level of a HVAC is usually measured with a pressure microphone positioned at a certain distance. This measurement is normally performed in an anechoic room. However, this method doesn't provide the engineer any insight on what noise sources do contribute to the overall noise level measured. A new...

The AMI Meeting Corpus: A Pre-Announcement

Abstract. The AMI Meeting Corpus is a multi-modal data set consisting of 100 hours of meeting recordings. It is being created in the context of a project that is developing meeting browsing technology and will eventually be released publicly. Some of the meetings it contains are naturally occurring, and some are elicited, particularly using a...

An experimental method for validating compressor valve vibration theory

This paper presents an experimental method for validating traditional compressor valve theory for unsteady flow conditions. Traditional valve theory considers the flow force acting on the plate and the flow rate as quasi-steady variables. These variables are related via semi-empirical coefficients which are determined by steady flow experiments....

Orifice impedance under grazing flow measured with a single microphone method

The effect of one-sided grazing mean flow on the acoustical impedance of rectangular orifices is measured at low Mach number and low Helmholtz number by means of a single microphone method. The results are fairly consistent with previous experimental results obtained by means of a two-microphone impedance tube. Furthermore no significant...

Digitally controlled active noise reduction with integrated speech communication

Active noise reduction is a successful addition to passive ear-defenders for improvement of the sound attenuation at low frequencies. Design and assessment methods are discussed, focused on subjective and objective attenuation measurements, stability, and high noise level applications. Active noise reduction systems are suitable for integration...

Laser-induced acoustic landmine detection with experimental results on buried landmines

Acoustic landmine detection (ALD) is a technique for the detection of buried landmines including non-metal mines. Since it gives complementary results with GPR or metal detection, sensor fusion of these techniques with acoustic detection would give promising results. Two methods are used for the acoustic excitation of the soil: laser excitation...

Sound Photographs to reveal vehicle pass-by sources with a calibrated source-strength level

In national and European discussions, it appears that the conventional sound measurement techniques are insufficient to answer some relevant questions with respect to source strength of road vehicles. An example of such a question is: What is the importance of tyre-road noise on the one hand and drive-line noise on the other hand in every day...

Prediction of wall-pressure fluctuations using the statistical approach to turbulence induced noise (Satin)

The noise prediction model SATIN (Statistical Approach to Turbulence /nduced Noise) is presented. SATIN assumes axial symmetric turbulence with the length scale ratio λ and the Reynolds stress ratio ξ as two anisotropy parameters. The model is based on Lighthill's acoustic analogy and allows to predict both the far-field noise radiation as well...

Experimental determination of pass-by noise contributions from the bogies and superstructure of a freight wagon

Pass-by noise from freight trains on straight tracks is dominated by rolling noise. The main contributions are generally accepted to originate from vibrations of the track and the wheels. However, there is uncertainty about the contributions from the bogie and the wagon superstructure. This article describes experimental methods to determine...

The cocktail party phenomenon A review of research on speech intelligibility in multiple-talker conditions

It is in most cases relatively easy to understand one talker even if other persons arc talking at the same time. Over the last decades, this so-called cocktail party phenomenon has been the subject of a considerable number of studies. In the present paper, an overview is given of part of this research, specifically those studies dealing with the...