An increasing attention has recently been paid to the effect of underwater noise field generated by ship activities on marine environment. Although this problem is widely discussed in international treaties and conventions, it not yet found a consolidated technical-scientific treatment capable quantifying level emissions produced naval systems. As part national research collaboration, novel cod...

To identify the factors affecting teachers’ vocal acoustic parameters, with aim of detecting individuals at risk phonotrauma. The voicing time, voice sound pressure level [SPL] and fundamental frequency [fo] 87 teachers were measured during one workweek using a dosimeter. We retrospectively investigated impact 10 (gender, age, teaching experience, level, tobacco, gastro-esophageal problems, non...

In this study, the impact of laser energy deposition on pressure oscillations and relative sound pressure levels (SPL) in an open supersonic cavity flow is investigated. Laser energy with a magnitude of 100 mJ is deposited on the flow just above the cavity leading edge and up to 7 dB of reduction is obtained in the SPL values along the cavity back wall. Additionally, proper orthogonal decomposi...

We proposed a piezoelectric artificial basilar membrane (ABM) composed of a microelectromechanical system cantilever array. The ABM mimics the tonotopy of the cochlea: frequency selectivity and mechanoelectric transduction. The fabricated ABM exhibits a clear tonotopy in an audible frequency range (2.92-12.6 kHz). Also, an animal model was used to verify the characteristics of the ABM as a fron...

According to current cochlear concepts, spontaneous otoacoustic emissions (SOAEs) are thought to be the product of outer hair cell (OHCs) movement. Furthermore, efferent neurofibers from the olivocochlear bundle primarily innervate OHCs. Thus, we designed this investigation to determine changes in SOAE under conditions of contralateral acoustic stimulation. Fouty-two normal ears of 34 subjects ...

Otoacoustic emission (OAE) tests of the medial-olivocochlear reflex (MOCR) in humans were assessed for viability as clinical assays. Two reflection-source OAEs [TEOAEs: transient-evoked otoacoustic emissions evoked by a 47 dB sound pressure level (SPL) chirp; and discrete-tone SFOAEs: stimulus-frequency otoacoustic emissions evoked by 40 dB SPL tones, and assessed with a 60 dB SPL suppressor] w...

Numerical simulations of unsteady flow in a Hartmann resonance tube are carried out with the goal of understanding the effect of jet Mach number on the flow characteristics. The device, which consists of a convergent nozzle facing a closed end tube produces a nearly normal shock that fluctuates in the gap between the nozzle and the tube. Numerical solutions were obtained for the unsteady Reynol...

BACKGROUND Noise pollution is currently a major health risk factor for workers in industries. The aim of this study was to investigate noise pollution and implement a control intervention plan for blast furnace in a steel industry. METHODS The measurement of sound pressure level (SPL) along with frequency analysis was done with the sound-level-meter Cell-450. Personal noise exposure was perfo...

simultaneous exposure of highly-used chemical and physical agents are expected to happen in many occupations. in the present study the impact of simultaneous exposure to noise and formaldehyde on oxidative stress in blood and liver tissue of rat was investigated. animal study was conducted in the school of public health, shahid beheshti university of medical scineces, tehran, iran in 2013. a to...

BACKGROUND There is still controversy regarding the influence of aging on medial olivocochlear (MOC) system function. The main objective of this study is to measure age-related changes of MOC system function in people with normal hearing thresholds. METHOD Bilateral assessment of the MOC effect for click-evoked otoacoustic emissions (CEOAEs; at 70±3 dB peak sound pressure level [pSPL], click ...