The effects of exposure of intense free‐field impulse noise on humans wearing hearing protection: Implications for new criteria

1998 ◽  
Vol 103 (5) ◽  
pp. 2877-2878 ◽  
Author(s):  
James H. Patterson ◽  
Daniel L. Johnson
Keyword(s):  
Impulse Noise ◽  
Free Field ◽  
Hearing Protection ◽  
New Criteria

Auditory Perception

1992 ◽  
Vol 36 (3) ◽  
pp. 247-247
Author(s):  
Ellen C. Haas
Keyword(s):  
Human Factors ◽  
Auditory Perception ◽  
Free Field ◽  
Auditory Signal ◽  
Auditory Stimuli ◽  
Hearing Protection ◽  
Speech Communication ◽  
Complex Signals ◽  
Research Issues ◽  
Auditory Signals

Auditory perception involves the human listener's awareness or apprehension of auditory stimuli in the environment. Auditory stimuli, which include speech communications as well as non-speech signals, occur in the presence and absence of environmental noise. Non-speech auditory signals range from simple pure tones to complex signals found in three-dimensional auditory displays. Special hearing protection device (HPD) designs, as well as additions to conventional protectors, have been developed to improve speech communication and auditory perception capabilities of those exposed to noise. The thoughtful design of auditory stimuli and the proper design, selection, and use of HPDs within the environment can improve human performance and reduce accidents. The purpose of this symposium will be to discuss issues in auditory perception and to describe methods to improve the perception of auditory stimuli in environments with and without noise. The issues of interest include the perception of non-speech auditory signals and the improvement of auditory perception capabilities of persons exposed to noise. The first three papers of this symposium describe the perception of non-speech auditory signals. Ellen Haas defines the extent to which certain signal elements affect the perceived urgency of auditory warning signals. Michael D. Good and Dr. Robert H. Gilkey investigate free-field masking as a function of the spatial separation between signal and masker sounds within the horizontal and median planes. Jeffrey M. Gerth explores the discrimination of complex auditory signal components that differ by sound category, temporal pattern, density, and component manipulation. The fourth paper of this symposium focuses upon the improvement of auditory perception capabilities of persons exposed to hazardous noise, and who must wear hearing protection. Special HPD designs, as well as additions to conventional protectors, have been developed to improve speech communication and auditory perception capabilities of persons exposed to noise. Dr. John G. Casali reviews several new HPD technologies and describes construction features, empirical performance data, and applications of each device. These papers illustrate current research issues in the perception of auditory signals. The issues are all relevant to the human factors engineering of auditory signals and personal protective gear. The perception of auditory stimuli can be improved by the thoughtful human factors design of auditory stimuli and by the proper use of HPDs.

Assessment of Impulse Noise Hazard and the Use of Hearing Protection Devices in Workplaces Where Forging Hammers are Used

2015 ◽  
Vol 39 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Rafał Młyński ◽  
Emil Kozłowski ◽  
Jan Adamczyk
Keyword(s):  
Sound Pressure Level ◽  
Impulse Noise ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Pressure Level ◽  
Hearing Protection ◽  
Exposure Level ◽  
Limit Values ◽  
Noise Parameters ◽  
Protection Devices

Abstract The impulse noise is agent harmful to health not only in the case of shots from firearms and the explosions of explosive materials. This kind of noise is also present in many workplaces in the industry. The paper presents the results of noise parameters measurements in workplaces where four different die forging hammers were used. The measured values of the C-weighted peak sound pressure level, the A-weighted maximum sound pressure level and A-weighted noise exposure level normalized to an 8 h working day (daily noise exposure level) exceeded the exposure limit values. For example, the highest measured value of the C-weighted peak sound pressure level was 148.9 dB. In this study possibility of the protection of hearing with the use of earplugs or earmuffs was assessed. The measurement method for the measurements of noise parameters under hearing protection devices using an acoustical test fixture instead of testing with the participation of subjects was used. The results of these measurements allows for assessment which of two tested earplugs and two tested earmuffs sufficiently protect hearing of workers in workplaces where forging hammers are used.

Evaluation of hearing protection devices with high-amplitude impulse noise

2011 ◽  
Vol 130 (4) ◽  
pp. 2433-2433
Author(s):  
Karl Buck ◽  
Sebastien DeMezzo ◽  
Pascal Hamery
Keyword(s):  
Impulse Noise ◽  
High Amplitude ◽  
Hearing Protection ◽  
Protection Devices

Preprocessing of magnetograms for magnetohydrostatic extrapolations

2021 ◽  
Author(s):  
Xiaoshuai Zhu ◽  
Thomas Wiegelmann ◽  
Bernd Inhester
Keyword(s):  
Active Region ◽  
Magnetic Fields ◽  
Magnetic Energy ◽  
Free Field ◽  
Original Data ◽  
Boundary Integral ◽  
New Criteria ◽  
Force Free Field ◽  
Surface Integrals

<p>Magnetohydrostatic (MHS) extrapolations are developed to model 3D magnetic fields and plasma structures in the solar low atmosphere by using measured vector magnetic fields on the photosphere. However, the photospheric magnetogram may be inconsistent with the MHS assumption. By applying Gauss‘ theorem to an isolated active region, we obtain a set of surface integrals of the magnetogram as criteria for a MHS system. The integrals are a subset of Aly’s criteria for a force-free field (FFF). Based on the new criteria, we preprocess the magnetogram to make it more consistent with the MHS assumption and, at the same time, close to the original data. As a byproduct, we also find the boundary integral that is used to compute the energy of a FFF usually underestimates the magnetic energy of an active region.</p>

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