Effects of Acoustic Treatment on Music Teachers' Exposure to Sound

2015 ◽  
Vol 39 (2) ◽  
pp. 159-163 ◽  
Author(s):  
Emil Kozłowski ◽  
Rafał Młyński
Keyword(s):  
Sound Pressure ◽  
Noise Exposure ◽  
Music Teachers ◽  
Pressure Level ◽  
French Horn ◽  
Exposure Level ◽  
Percussion Instruments ◽  
Exposure Levels ◽  
Teaching Music ◽  
Acoustic Treatment

Abstract In this study, music teachers' exposure to sound was tested by measuring the A-weighted equivalent sound pressure level (SPL), the A-weighted maximum SPL and the C-weighted peak SPL. Measurements were taken prior to and after acoustic treatment in four rooms during classes of trumpet, saxophone, French horn, trombone and percussion instruments. Results showed that acoustic treatment affects the exposure of music teachers to sound. Daily noise exposure levels (LEX, 8 h) for all teachers exceeded a limit of 85 dB while teaching music lessons prior to room treatment. It was found that the LEX, 8 h values ranged from 85.8 to 91.6 dB. The highest A-weighted maximum SPL and C-weighted peak SPL that music teachers were exposed to were observed with percussion instruments (LAmax = 110.4 dB and LCpeak = 138.0 dB). After the treatments, daily noise exposure level decreased by an average of 5.8, 3.2, 3.0, 4.2 and 4.5 dB, respectively, for the classes of trumpet, saxophone, French horn, trombone and drums, and did not exceed 85 dB in any case.

scholarly journals Occupational Noise Exposure of Traffic Enforcers in Selected Streets in the City of Manila

2018 ◽  
Vol 52 (3) ◽  
Author(s):  
Louise Elinor R. Dulay ◽  
Ma. Danica Katrina P. Galvan ◽  
Rio Joana M. Puyaoan ◽  
Angel Abraham Y. Sison ◽  
Nicole S. Natanauan ◽  
...  
Keyword(s):  
Occupational Safety ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Occupational Safety And Health ◽  
Exposure Level ◽  
Safety And Health ◽  
Health Standards ◽  
Exposure Levels ◽  
The Mean ◽  
The City

Objective. The study aimed to evaluate the sound pressure levels of selected traffic enforcer sites in the City of Manila. Methods. A Brüel & Kjær Integrating Sound Level Meter type 2225 was used to measure sound pressure levels in dB(A) to estimate personal noise exposure of traffic enforcers designated at Quezon Boulevard near Quiapo Church and Recto – Rizal Avenue on a weekday and a weekend. Graphs were generated while appropriate measures were calculated for the noise exposure levels. The mean exposure levels were compared with the Philippine Occupational Safety and Health standards by computing the corresponding permissible exposure limit for each work shift using the Equal Energy Principle.17 Results. Noise exposure levels at Quezon Boulevard ranged from 75.0 dB(A) to 91.5 dB(A) with mean noise exposure level of 84.3 ± 3.7 dB(A) and 82.5 ± 2.6 dB(A) for the weekday AM and PM shift, respectively. The mean noise exposure level at Quezon Boulevard for the weekend AM shift was 82.4 ± 2.6, whereas 80.4 ± 2.8 for the PM shift. The noise exposure levels at Recto – Rizal Avenue ranged from 81.5 dB(A) to 99.3 dB(A) with mean noise exposure level of 86.7 ± 2.6 dB(A) and 86.0 ± 2.1 dB(A) for the weekday AM and PM shift, respectively. The mean noise exposure level at Recto – Rizal Avenue for the weekend AM shift was 86.7 ± 2.3, whereas 89.0 ± 4.0 for the PM shift. Conclusion. The study showed that traffic enforcers designated at Quezon Boulevard and Recto – Rizal Avenue are exposed to noise levels that do not exceed the Philippine Occupational Safety and Health standards.

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.

scholarly journals University music teachers' exposure to noise and hearing loss

2017 ◽  
Vol 1 (1) ◽  
pp. 49-58
Author(s):  
A. Delgado ◽  
F. Carvalho ◽  
R. B. Melo
Keyword(s):  
Hearing Loss ◽  
Extracurricular Activities ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Music Teachers ◽  
Brass Instruments ◽  
School Of Music ◽  
Exposure Levels ◽  
Hearing Damage ◽  
High Sound

Musical instruments and singers' voices can reach high sound pressure values representing a risk to hearing health, which is of particular relevance for music teachers. Therefore, the potential risk of hearing damage among music teachers in a university school of music was assessed. Twenty teachers completed all phases of the study. Sound pressure levels were measured with a sound meter and daily noise exposure levels were computed and compared with legal reference values in force. Three types of hearing exams were administered to all teachers by health technicians. Most teachers (75%) were subjected to daily noise exposure levels below 80 dB(A). Teaching to play brass instruments appears to be the most risky activity. Only three subjects were diagnosed with noise-induced hearing loss, which cannot be exclusively ascribed to occupational activities because they are involved in extracurricular activities. Increased sample size and the use of noise dosimetry would have improved the study conclusions.

scholarly journals Repeated Noise Exposure Does Not Reach Hazardous Levels During Total Joint Arthroplasty

2020 ◽  
Vol 185 (9-10) ◽  
pp. e1551-e1555
Author(s):  
Sean E Slaven ◽  
Benjamin M Wheatley ◽  
Daniel L Christensen ◽  
Sameer K Saxena ◽  
Robert J McGill
Keyword(s):  
Noise Exposure ◽  
Weighted Average ◽  
Sound Level ◽  
Health Concern ◽  
Exposure Level ◽  
Total Knee ◽  
Time Weighted Average ◽  
Exposure Levels ◽  
Occupational Standards ◽  
Level Meter

Abstract Introduction Noise exposure is an occupational health concern for certain professions, especially military servicemembers and those using power tools on a regular basis. The purpose of this study was to quantify noise exposure during total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases compared to the recommended standard for occupational noise exposure. Materials and Methods A sound level meter was used to record cumulative and peak noise exposure levels in 10 primary THA and 10 primary TKA surgeries, as well as 10 arthroscopy cases as controls. Measurements at the distance of the surgeon were taken in all cases. In TKA cases, measurements were taken at 3 feet and 8 feet from the surgeon, to simulate the position of the anesthetist and circulating nurse, respectively. Results Time-weighted average was significantly higher in THA (64.7 ± 5.2 dB) and TKA (64.5 ± 6.8 dB) as compared to arthroscopic cases (51.1 ± 7.5 dB, P < 0.001) and higher at the distance of the surgeon (64.5 ± 6.8 dB) compared to the anesthetist (52.9 ± 3.8 dB) and the circulating nurse (54.8 ± 11.2 dB, P = 0.006). However, time-weighted average was below the recommended exposure level of 85 dB for all arthroplasty cases. Peak levels did not differ significantly between surgery type or staff role, and no values above the ceiling limit of 140 dB were recorded. Surgeon’s daily noise dose percentage per case was 1.78% for THA and 2.04% for TKA. Conclusion Noise exposure in THA and TKA was higher than arthroscopic cases but did not exceed occupational standards. A daily dose percentage of approximately 2% per case indicates that repeated noise exposure likely does not reach hazardous levels in modern arthroplasty practice.

scholarly journals Landscape depressions can create silent zones in noise polluted parks

2021 ◽  
Vol 263 (4) ◽  
pp. 2550-2554
Author(s):  
Timothy Van Renterghem ◽  
Pieter Thomas ◽  
Dick Botteldooren
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Road Traffic ◽  
Traffic Noise ◽  
Pressure Level ◽  
Road Traffic Noise ◽  
Efficient Measure ◽  
Natural Means

Excessive road traffic noise exposure in (sub)urban parks hinders its restorative function and will negatively impact the number of visitors. Especially in such green environments, noise abatements by natural means, well integrated in the landscape, are the most desired solutions. Although dense vegetation bordering the park or raised berms could come first in mind, local landscape depressions are typically underused. In this work, a case-study of a small suburban park, squeezed in between two major arterial roads, is analyzed. The spatially dependent road traffic noise exposure in the park is assessed in detail by mobile sound pressure level measurements. Local reductions of up to 6-7 dBA are found at landscape depressions of only a few meters deep. It can therefore be concluded that this is an efficient measure and should be added to the environmental noise control toolbox for noise polluted parks.

scholarly journals Supersonic Windtunnel Noise Attenuation

2021 ◽  
Author(s):  
William Wai Lim Wong
Keyword(s):  
Wind Tunnel ◽  
Sound Pressure Level ◽  
Noise Level ◽  
Sound Pressure ◽  
Power Level ◽  
Mesh Size ◽  
Acoustic Power ◽  
Pressure Level ◽  
Supersonic Wind Tunnel ◽  
Acoustic Treatment

The aerodynamic generated noise in the supersonic wind tunnel during operation at Ryerson University has exceeded the threshold of hearing damage. An acoustic silencer was to be designed and added to the wind tunnel to reduce the noise level. The main sources of noise generated from the wind tunnel with the silencer were identified to be located at the convergent divergent nozzle and the turbulent region downstream of the shock wave at the diffuser with the maximum acoustic power level of the entire wind tunnel at 161.09 dB. The designed silencer provided an overall sound pressure level reduction of 21.41 db which was considered as acceptable. Refinement to the mesh size and changes to the geometry of the mixing chamber was suggested for a more accurate result in noise output as well as flow conditions would match up to the physical flow. Additional acoustic treatment should be applied to the wind tunnel to further reduce sound pressure level since the noise level still exceeded the threshold of hearing loss.

Temporary Threshold Shift from a Toy Cap Gun

1974 ◽  
Vol 39 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Lynne Marshall ◽  
John F. Brandt
Keyword(s):  
Hearing Loss ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Pressure Level ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Fixed Frequency ◽  
Before And After ◽  
The Subject

Temporary threshold shift resulting from exposure to one and five toy cap gun pistol shots was investigated using 11 normal-hearing adult subjects and one subject with a noise-induced hearing loss. The subjects fired the cap gun at arm’s length, and absolute thresholds at 4000 Hz were obtained before and after noise exposure by a fixed-frequency Bekesy technique. After exposure to one gunshot, five subjects showed a small TTS, five demonstrated no TTS, and two (including the subject with the hearing loss) exhibited negative TTS. No TTS occurred in any of the subjects after exposure to five shots. It was postulated that the small amount of TTS was due to the unexpectedly low sound pressure level produced by the cap gun and to the contraction of the middle ear muscles in some subjects prior to firing.

scholarly journals Environmental noise degrades hippocampus-related learning and memory

2020 ◽  
Vol 118 (1) ◽  
pp. e2017841117
Author(s):  
Yifan Zhang ◽  
Min Zhu ◽  
Yutian Sun ◽  
Binliang Tang ◽  
Guimin Zhang ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Long Term Potentiation ◽  
Modern Human ◽  
Pressure Level ◽  
Neural Mechanisms ◽  
Loud Noise ◽  
Term Potentiation

The neural mechanisms underlying the impacts of noise on nonauditory function, particularly learning and memory, remain largely unknown. Here, we demonstrate that rats exposed postnatally (between postnatal days 9 and 56) to structured noise delivered at a sound pressure level of ∼65 dB displayed significantly degraded hippocampus-related learning and memory abilities. Noise exposure also suppressed the induction of hippocampal long-term potentiation (LTP). In parallel, the total or phosphorylated levels of certain LTP-related key signaling molecules in the synapses of the hippocampus were down-regulated. However, no significant changes in stress-related processes were found for the noise-exposed rats. These results in a rodent model indicate that even moderate-level noise with little effect on stress status can substantially impair hippocampus-related learning and memory by altering the plasticity of synaptic transmission. They support the importance of more thoroughly defining the unappreciated hazards of moderately loud noise in modern human environments.

scholarly journals Farmed Salmon Show No Pathological Alterations When Exposed to Acoustic Treatment for Sea Lice Infestation

2021 ◽  
Vol 9 (10) ◽  
pp. 1114
Author(s):  
Marta Solé ◽  
Maria Constenla ◽  
Francesc Padrós ◽  
Antoni Lombarte ◽  
José-Manuel Fortuño ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Sea Lice ◽  
Histopathological Analysis ◽  
Microscopy Imaging ◽  
Farmed Salmon ◽  
Sound Exposure ◽  
Innovative Method ◽  
Exposure Levels ◽  
Exposure Sessions ◽  
Acoustic Treatment

The use of bioacoustic methods to address sea lice infestation in salmonid farming is a promising innovative method but implies an exposure to sound that could affect the fish. An assessment of the effects of these techniques related to the salmon’s welfare is presented here. The fish were repeatedly exposed to 350 Hz and 500 Hz tones in three- to four-hour exposure sessions, reaching received sound pressure levels of 140 to 150 dB re 1 µPa2, with the goal of reaching total sound exposure levels above 190 dB re 1 µPa2 s. Gross pathology and histopathological analysis performed on exposed salmons’ organs did not reveal any lesions that could be associated to sound exposure. The analysis of their otoliths through electron microscopy imaging confirmed that the sound dose that was used to impair the lice had no effects on the fish auditory organs.

scholarly journals Noise Emissions in Milking Parlours with Various Construction Solutions

2016 ◽  
Vol 19 (2) ◽  
pp. 49-51
Author(s):  
Marie Šístková ◽  
Martin Pšenka ◽  
Ivo Celjak ◽  
Petr Bartoš ◽  
Štefan Mihina ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Pressure Level ◽  
Different Types ◽  
Sound Pressure Levels ◽  
Mechanical Devices

Abstract Mechanical devices in parlours are a source of noise, and this noise has an effect not only on the operators of the parlour but also on dairy cows. They have more sensitive hearing than humans. The aim of this article was to analyse the sound pressure level and determine the noise exposure of dairy cows at different technological solutions of milking parlours, during their day routine. In the experiment, tandem, herringbone and rotary milking parlours were used. Noise exposure was measured during the milking process. After evaluation of noise pressure levels of different types of milking parlours, it can be concluded that in this experiment, the equivalent noise pressure level was lowest in the tandem milking parlour. Equivalent sound pressure levels in the rotary and herringbone milking parlour were almost about the same values. These values are higher than values in the tandem milking parlour, about 10 decibels. The differences within mean LAFeq values between the herringbone milking parlour and tandem milking parlour were highly statistically significant (P <0.001***).

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