Determining the effectiveness of impulse noise attenuation with hearing protection devices (HPDs) is an important part of their selection. Measuring impulse noise parameters under an HPD would involve exposing subjects to impulses with a high peak sound pressure level. This paper presents a computational method of determining impulse noise parameters under the cups of earmuffs. Calculations are...

There are no known medical or physiological reasons why HPDs should be suspected of causing any of the remaining maladies listed above2. However, when an employee voices such complaints, this indicates dissatisfaction with the HPD he is wearing, a misunderstanding of the need for its use, or a real health problem that has been mistakenly attributed to the use of the HPD. The best response will ...

Material and methods Surface measurements (Formetric) of kyphosis/lordosis were considered the Gold Standard [1]. Correlations between Human PD (HPD), Formetric PD (FPD) and Gold Standard were searched in 129 school screening pupils (age 11.8±0.7): not correlated PD were eliminated. ROC-curve statistical technique was used to determine the best cut-off for remaining PDs. Final FPD were verified...

In previous EARLogs1 we have discussed how to measure and rate the attenuation of hearing protection devices (HPDs) in the laboratory, how these devices affect auditory communications, and perhaps most importantly how HPDs perform in real world (RW) environments. It was found that laboratory attenuation measurements significantly overestimate the RW performance of HPDs, due to the unrealistic, ...

Aim To test six hypotheses that could explain or mediate the positive correlation between human population density (HPD) and bird species richness while controlling for biased sampling effort. These hypotheses were labelled as follows: productivity (net primary productivity, NPP); inherent heterogeneity (diversity of vegetation types); anthropogenic heterogeneity (diversity of land uses); conse...

INTRODUCTION The viability of hearing protection device (HPD) verification (i.e., fit-testing) on a large scale was investigated to address this gap in a military accession environment. MATERIALS AND METHODS Personal Attenuation Ratings (PARs) following self-fitted (SELF-Fit) HPDs were acquired from 320 US Marine Corps training recruits (87.5% male, 12.5% female) across four test protocols (1...

This paper proposes a class of covariance estimators based on information divergences in heterogeneous environments. In particular, the problem of covariance estimation is reformulated on the Riemannian manifold of Hermitian positive-definite (HPD) matrices. The means associated with information divergences are derived and used as the estimators. Without resorting to the complete knowledge of t...