scholarly journals Octave band noise exposure: Laboratory models and otoprotection efforts

2019 ◽  
Vol 146 (5) ◽  
pp. 3800-3810 ◽  
Author(s):  
Sarah N. Gittleman ◽  
Colleen G. Le Prell ◽  
Tanisha L. Hammill
Keyword(s):  
Noise Exposure ◽  
Octave Band ◽  
Band Noise ◽  
Laboratory Models

Hearing threshold shifts and recovery in harbor seals (Phoca vitulina) after octave-band noise exposure at 4 kHz

2012 ◽  
Vol 132 (4) ◽  
pp. 2745-2761 ◽  
Author(s):  
Ronald A. Kastelein ◽  
Robin Gransier ◽  
Lean Hoek ◽  
Amy Macleod ◽  
John M. Terhune
Keyword(s):  
Noise Exposure ◽  
Hearing Threshold ◽  
Phoca Vitulina ◽  
Harbor Seals ◽  
Octave Band ◽  
Band Noise

Effects of Infrasound on Human Body Sway

1988 ◽  
Vol 7 (2) ◽  
pp. 66-73 ◽  
Author(s):  
Hiroshi Takigawa ◽  
Fumiyo Hayashi ◽  
Shizuko Sugiura ◽  
Hiroshi Sakamoto
Keyword(s):  
Spectral Analysis ◽  
Human Body ◽  
Noise Exposure ◽  
Vestibular Function ◽  
Body Sway ◽  
Subjective Symptoms ◽  
Octave Band ◽  
Trace Length ◽  
Band Noise ◽  
Healthy Males

Some individuals who have been exposed to infrasound have complained of subjective symptoms which seemed to be an offshoot of the changes in vestibular function. This study was undertaken in order to clarify the latter assumption by observing the change of mode of postural control upon subjecting to infrasound vis-a-vis noise exposure. Thirty-four healthy males were subjected to a wide octave-band noise, 16 Hz and 5 Hz at 95 dB for 5 minutes. Their body sway was measured before and during exposure. The trace-length and the power percentage by spectral analysis were determined from their body sway. Our present findings show that the mode of body sway was temporarily confused at the time of switchover from opening to closing of the subject's eyes in the pre-exposed condition. This confusion was inhibited by exposure to infrasound. No effects were however observed upon exposure to noise. These results are taken to suggest that the excitability of the vestibulum was accelerated upon exposure to infrasound, whether or not the subjects perceived any sensations.

Temporary Threshold Shifts Produced by Exposure to High-Frequency Noise

1972 ◽  
Vol 15 (3) ◽  
pp. 624-631 ◽  
Author(s):  
John H. Mills ◽  
Seija A. Talo
Keyword(s):  
High Frequency ◽  
Noise Exposure ◽  
Sound Field ◽  
Acoustic Properties ◽  
Threshold Shift ◽  
Maximum Effect ◽  
Frequency Noise ◽  
Temporary Threshold Shift ◽  
Octave Band ◽  
Band Noise

Four chinchillas, monaural and trained in behavioral audiometry, were exposed for 24 days in a diffuse-sound field to an octave-band noise centered at 4.0 k Hz. The octave-band levels (OBL re 0.0002 ubar) were 57 dB for Days 1 to 6; 65 dB for Days 7 to 12; 72 dB for Days 13 to 18; and 80 dB for Days 19 to 24. At regular intervals throughout the noise exposure each animal was removed from the noise and threshold measurements were made. For each level of noise, temporary threshold shift reached an asymptote. In the frequency region of maximum effect, the relation between temporary threshold shift and the level of the noise is given by the equation TTS 4 ∞ = 1.6 (OBL-47) where TTS 4 ∞ is the temporary threshold shift at asymptote measured at a postexposure time of four minutes. These results for a noise centered at 4.0 k Hz in combination with those results for a noise centered at 0.5 k Hz suggest that bands of noise produce equal TTS 4 ∞ when the levels of the noises are equated for the acoustic properties of the external ear (including the head) and the inner ear.

Decay of Temporary Threshold Shift in Noise

1973 ◽  
Vol 16 (2) ◽  
pp. 267-270 ◽  
Author(s):  
John H. Mills ◽  
Seija A. Talo ◽  
Gloria S. Gordon
Keyword(s):  
Sound Field ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Octave Band ◽  
Band Noise ◽  
Lower Asymptote

Groups of monaural chinchillas trained in behavioral audiometry were exposed in a diffuse sound field to an octave-band noise centered at 4.0 k Hz. The growth of temporary threshold shift (TTS) at 5.7 k Hz from zero to an asymptote (TTS ∞ ) required about 24 hours, and the growth of TTS at 5.7 k Hz from an asymptote to a higher asymptote, about 12–24 hours. TTS ∞ can be described by the equation TTS ∞ = 1.6(SPL-A) where A = 47. These results are consistent with those previously reported in this journal by Carder and Miller and Mills and Talo. Whereas the decay of TTS ∞ to zero required about three days, the decay of TTS ∞ to a lower TTS ∞ required about three to seven days. The decay of TTS ∞ in noise, therefore, appears to require slightly more time than the decay of TTS ∞ in the quiet. However, for a given level of noise, the magnitude of TTS ∞ is the same regardless of whether the TTS asymptote is approached from zero, from a lower asymptote, or from a higher asymptote.

scholarly journals Octave Band Technique for Noise Measurement at the Source, Path, and Receiver of Gas Turbines in Oil and Gas Facilities

2022 ◽  
Vol 30 (1) ◽  
pp. 725-745
Author(s):  
Akmal Haziq Mohd Yunos ◽  
Nor Azali Azmir
Keyword(s):  
Gas Turbine ◽  
Noise Level ◽  
Gas Turbines ◽  
Noise Exposure ◽  
Oil And Gas ◽  
Noise Pollution ◽  
Noise Measurement ◽  
Octave Band ◽  
High Noise ◽  
Safety And Health

Noise measurement is essential for industrial usage. However, further attention to preventing noise pollution is needed, especially when working with equipment generating a high noise level, such as gas turbines. This study aims to determine the best way to perform noise measurement and analyze the octave band frequency generated by noise pollution caused by gas turbine equipment. Data from site measurements show that the gas turbines produce more than 85 dB of noise with a Z-weighted measurement. A noise measuring investigation was conducted to obtain the data for the 1/3 octave band. A frequency-domain was used to comprehend the properties of the noise measurement frequency band. The frequency band was classified into three different zones called low, medium, and high frequency, which is useful in noise measurement analysis to identify a viable solution to reduce the noise. On-site sampling was performed at the source, path, and receiver of three separate gas turbine locations within oil and gas operations. The 1/3 octave band data collection results at the sound source, path, and receiver demonstrate the noise level distribution at the perimeter of gas turbine installations in the low and medium frequency ranges. Most of the high noise frequency range is between 250 Hz and 2 kHz for source, path, and receiver. All acquired values are compared to the Department of Safety and Health (Occupational Safety and Health (Noise Exposure) Regulations 2019 in Malaysia. As a result, oil and gas service operators can monitor and take countermeasures to limit noise exposure at oil and gas facilities.

Temporary threshold shift in pinnipeds induced by octave‐band noise in water

1999 ◽  
Vol 106 (4) ◽  
pp. 2251-2251
Author(s):  
David Kastak ◽  
Brandon L. Southall ◽  
Ronald J. Schusterman ◽  
Colleen J. Reichmuth
Keyword(s):  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Octave Band ◽  
Band Noise

scholarly journals The masking of octave-band noise by broad-spectrum noise: A comparison of infant and adult thresholds

1981 ◽  
Vol 30 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Dale Bull ◽  
Bruce A. Schneider ◽  
Sandra E. Trehub
Keyword(s):  
Broad Spectrum ◽  
Octave Band ◽  
Band Noise

scholarly journals Intensive Differential Thresholds for Octave Band Noise

1959 ◽  
Vol 31 (1) ◽  
pp. 128-128
Author(s):  
Arnold M. Small ◽  
W. Edward Bacon ◽  
James L. Fozard
Keyword(s):  
Octave Band ◽  
Band Noise

Hearing Protection With Integrated In-Ear Dosimetry: A Noise Dose Study

2012 ◽  
Author(s):  
Melissa A. Theis ◽  
Hilary L. Gallagher ◽  
Richard L. McKinley ◽  
Valerie S. Bjorn
Keyword(s):  
Noise Exposure ◽  
National Standards ◽  
Hearing Protection ◽  
Octave Band ◽  
Noise Levels ◽  
Exposure Limits ◽  
Group Data ◽  
Dose Study ◽  
Hearing Protector ◽  
Naval Air Systems Command

Military personnel working in high noise environments can be exposed to continuous noise levels up to 150 dB. United States (US) Department of Defense (DoD) Hearing Conservation Programs (HCPs) [1–3] set safe noise exposure limits to reduce the risk for noise induced hearing loss. These daily noise exposure limits were based on ambient noise levels and the duration of time spent in that noise environment. Current dosimeters, worn on the lapel of personnel and at least one system worn under a hearing protector, were designed to measure noise levels and calculate noise dose, but do not provide a validated measure of noise dose external to or under a hearing protector. Noise dose under hearing protectors can be estimated by subtracting the real ear attenuation (REAT) data, collected in accordance with the American National Standards Institute (ANSI) S12.6 [4], at each octave band from the ambient octave band noise. This procedure gives accurate results for group data, but does not account for individual variations in effective attenuation. To address this issue, the US Naval Air Systems Command (NAVAIR) led the development of ship suitable in-ear dosimetry integrated into a hearing protector, and co-sponsored an effort executed by the Air Force Research Laboratory (AFRL) to calibrate in-ear noise dose readings. This was accomplished by conducting human noise exposure experiments, with and without hearing protection, which calculated noise dose from temporary threshold shifts (TTS) in hearing. Ten subjects participated in the study. Noise levels were 91, 94, and 97 dB for up to 2 hrs, 1 hr, and 30 minutes respectively. These exposure levels were well within US DoD safe noise exposure guidelines (DoD HCP) [1–3]. Data will be presented describing the open and occluded (protected) ear TTS response to noise dose achieved by subjects in the experiment. Preliminary findings indicate that human subject data is extremely important in developing and validating calibration factors for any type of noise dosimeter but is especially important for in-ear dosimetry. Results from this study demonstrated that the REAT noise dose estimations and the in-ear dosimetry earplugs consistently overestimated the effective noise dose received by subjects. However, more than 10 subjects are required to improve the confidence level of the estimated calibration factor.

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