Multi-component data are not usually processed with specifically designed procedures, but with procedures analogous to the ones used for single-component data. Commonly, the vertical and horizontal components of the data are taken as proxies for P and S wave modes which are imaged independently with the acoustic wave equation. This procedure works only if the vertical and horizontal component a...

This paper deals with source localization techniques in time domain for broadband acoustic sources. The goal is to detect accurately and quickly the position and amplitude of noise sources in workplaces in order to prevent employees from hearing loss or safety risk. First, the generalized cross correlation associated with a spherical microphone array is used to get a raw noise source map. Then ...

The feasibility of making spatially resolved measurements of blood flow using pulsed photoacoustic Doppler techniques has been explored. Doppler time shifts were quantified via cross-correlation of pairs of photoacoustic waveforms generated within a blood-simulating phantom using pairs of laser light pulses. The photoacoustic waves were detected using a focussed or planar PZT ultrasound transdu...

A convincing detection of primordial non-Gaussianity in the local form of the bispectrum, whose amplitude is given by the ƒNL parameter, offers a powerful test of inflation. In this paper, we calculate the modification of two-point cross-correlation statistics of weak lensing—galaxy-galaxy lensing and galaxycosmic microwave background (CMB) crosscorrelation—due to ƒNL. We derive and calculate t...

As a sea of fire fills the sky and voices of loved ones are drowned in a stream of explosions, New Year’s Eve can resemble a war zone. Remarkably, few perceive the chaotic event as disorienting. Instead of experiencing a disorganised flux of bursts and blazes, people link specific flashes and bangs – even if they were separated by hundreds of milliseconds – to a single cause, and enjoy a struct...

To find the position of an acoustic source in a room, a set of relative delays among different microphone pairs has to be determined. The generalized cross-correlation method is the most popular to do so and is well explained in a landmark paper by Knapp and Carter. In this technical memorandum, we show how we can take advantage of the redundancy when more than two microphones are available. It...

[1] Fractures play an important role in the Earth’s crust, often controlling both mechanical and transport processes. Developing a mechanistic understanding of these processes requires quantifying the roughness of fracture surfaces and the contacts and void spaces between fracture surfaces at high spatial resolution (10s of microns) over a broad range of scales (centimeters to meters). Here we ...

This paper describes a speech enhancement system that significantly improves speech intelligibility of noisy speech in the context of a speech coder in low SNR conditions. The system uses two state-of-the-art non-acoustic sensors, a general electromagnetic motion sensor (GEMS) that detects the internal motions of glottis, and a physiological microphone (P-mic) that measures vibrations of the sk...