Humans are able to pay selective attention to music or speech in the presence of multiple sounds. It has been reported that in the speech domain, selective attention enhances the cross-correlation between the envelope of speech and electroencephalogram (EEG) while also affecting the spatial modulation of the alpha band. However, when multiple music pieces are performed at the same time, it is unclear how selective attention affects neural entrainment and spatial modulation.
View Article and Find Full Text PDFIn this Letter, we propose to use Fresnel lenses for holographic sound-field imaging. Although a Fresnel lens has never been used for sound-field imaging mainly due to its low imaging quality, it has several desired properties, including thinness, lightweight, low cost, and ease of making a large aperture. We constructed an optical holographic imaging system composed of two Fresnel lenses used for magnification and demagnification of the illuminating beam.
View Article and Find Full Text PDFJASA Express Lett
November 2021
When measuring a parametric acoustic array (PAA) with a microphone, the sound often suffers from so-called spurious sound, the noise generated by the nonlinearity of the microphone. This paper proposes a spurious-sound-free measurement method for a PAA using optical interferometry and Gaussian beam expansion. Comparison between the proposed method and numerical simulation by the finite element method confirmed that the proposed method measures the demodulated audio sound without any effect from spurious sound.
View Article and Find Full Text PDFA midfringe locked interferometer with differential detection is proposed for non-contact optical sound measurement, and the equivalent noise level of approximately 0 dB SPL/Hz is achieved. The noise level of the proposed method is 30 dB lower than that of a very recent laser Doppler vibrometer and close to that of a quarter-inch measurement microphone. The midfringe locking stabilizes the optical interferometer against slow environmental fluctuations and enables detection of the acoustic signal directly from optical intensity.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
September 2010
We developed a scheme for evaluating the size of the largest connected subnetwork (giant component) in random networks and the percolation threshold when sites (nodes) and/or bonds (edges) are removed from the networks based on the cavity method of statistical mechanics of disordered systems. We apply our scheme particularly to random networks of bimodal degree distribution (two-peak networks), which have been proposed in earlier studies as robust networks against random failures of site and/or targeted (random degree-dependent) attacks on sites. Our analysis indicates that the correlations among degrees affect a network's robustness against targeted attacks on sites or bonds nontrivially depending on details of network configurations.
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