A novel and practical acoustic energy harvesting mechanism to harvest traveling sound at low audible frequency is introduced and studied both experimentally and numerically. The acoustic energy harvester in this study contains a quarter-wavelength straight tube resonator with lead zirconate titanate (PZT) piezoelectric cantilever plates placed inside the tube. When the tube resonator is excited...

The active noise control of sinusoidal sound in free space has received considerable attention in the last few years. In a number of practical situations, the sound radiated in free space by extended sources needs to be globally reduced. This is the case of electrical power transformers, for example [1]. Nelson and Elliott have demonstrated that sound power attenuation can be achieved by active...

The paper deals with the design of a sound recognition system focused on an ultra low power hardware implementation in a button like miniature form factor. We present the results of the first design phase focused on selection and experimental evaluation of sound classes and algorithms suitable for low power realization. We also present the VHDL model of the hardware showing that our method can ...

In this paper, we propose a method for composing templates of lung sound classification. First, we obtain a sequence of power spectra by FFT for each given lung sound and compute a small number of component spectra by ICA for each of the overlapping sets of tens of consecutive power spectra. Second, we put component spectra obtained from various lung sounds into a single set and conduct cluster...

Current propositions of the quantity of sound driving the central auditory system, specifically around threshold, are diverse and at variance with one another. They include sound pressure, sound power, or intensity, which are proportional to the square of pressure, and energy, i.e., the integral of sound power over time. Here we show that the relevant sound quantity and the nature of the thresh...

The NMIJ, National Metrology Institute of Japan planned to start calibration service for reference sound sources (RSSs) by 2015 and we have been developing the RSS calibration system in accordance with ISO 6926. In our system, hemi-anechoic environment necessary for the calibration is realized by laying down wooden boards on a wire meshed floor of our anechoic room. In this study, we investigat...

critical analysis of power discourse in zeinab habash’s poems discourse analysis is a modern approach which flourishing and growing in the context of postmodernism. norman fairclough’s three-dimensional framework in critical discourse analysis is one of the most practical aspects of this theory that includes analysis of (spoken or written) language texts, analysis of discourse practice (process...

An insert ear-canal probe including sound source and microphone can deliver a calibrated sound power level to the ear. The aural power absorbed is proportional to the product of mean-squared forward pressure, ear-canal area, and absorbance, in which the sound field is represented using forward (reverse) waves traveling toward (away from) the eardrum. Forward pressure is composed of incident pre...

Autonomous listening devices are increasingly used to study vocal aquatic animals, and there is a constant need to record longer or with greater bandwidth, requiring efficient use of memory and battery power. Real-time compression of sound has the potential to extend recording durations and bandwidths at the expense of increased processing operations and therefore power consumption. Whereas los...