Using an automated clarinet playing system, the frequency f, sound level L, and spectral characteristics are measured as functions of blowing pressure P and the force F applied by the mechanical lip at different places on the reed. The playing regime on the (P,F) plane lies below an extinction line F(P) with a negative slope of a few square centimeters and above a pressure threshold with a more...

A transformation was derived to convert sound-pressure levels referenced to an NBS-9A coupler to corresponding eardrum sound-pressure levels. It was found that the same transformation may be used for male and female adults and for both TDH-39 and TDH-49 earphones in MX-41/AR supra-aural cushions. It was determined that from 250-2000 Hz the transformation provides an eardrum sound-pressure level...

The inherent attenuation of a homogeneous viscous medium limits radiation propagation, thereby restricting the use of many high-frequency acoustic devices to only short-range applications. Here, we design and experimentally demonstrate an acoustic metamaterial localization cavity which is used for sound pressure level (SPL) gain using double coiled up space like structures thereby increasing th...

In conventional near-field acoustic holography (NAH) it is not possible to distinguish between sound from the two sides of the array, thus, it is a requirement that all the sources are confined to only one side and radiate into a free field. When this requirement cannot be fulfilled, sound field separation techniques make it possible to distinguish between outgoing and incoming waves from the t...

Previous studies have shown that daily, moderate-level sound exposure, or conditioning, can reduce injury from a subsequent high-level noise exposure. We tested the hypothesis that this conditioning produces an increased activity in the olivocochlear efferent reflex, a reflex known to provide protection to the cochlea. Guinea pigs were conditioned by a 10-day intermittent exposure to 2-4 kHz no...

Acoustic metastructures are artificial structures which can manipulate the wavefront in sub-wavelength dimensions, and previously proposed acoustic have been mostly realized with single materials. An metastructure composite structure is for underwater stealth considering both manipulation sound absorption. The unit cells of composed a metallic supporting lattice, interconnecting polymer materia...

background: noise pollution has a particular importance in quiet environments such as hospitals. the main objective of this study was to evaluate the effects of noise exposure on the auditory system, blood pressure and precision, concentration and other psycho-neural components. methods: this cross-sectional study was carried out in three large hospitals of shiraz, during the period of 2012 to ...

In-the-ear calibration of sound pressure level may be problematic at frequencies above 2 kHz, because the pressure can vary significantly along the length of the ear canal, due to reflection of sound waves at the eardrum. This issue has been investigated by measuring behavioral thresholds to tones in a group of human subjects (N = 61) for two different insertion depths of an insert earphone. Th...