Complex noise exposures: An energy analysis

Ahroon, William A.; Hamernik, Roger P.; Davis, Robert I.

doi:10.1121/1.405406

Cited by 50 publications

(34 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The EEH based approach has been used to establish and implement noise guidelines because of its simplicity. However, the approach is generally considered appropriate for steady-state noise but not for complex noise, a steady-state noise embedded with impulsive noises (Ahroon et al, 1993). Some researchers have argued for the application of EEH in complex noise environments (Atherley and Martin, 1971;Guberan et al, 1971;Atherley, 1973), which however has largely been rebutted both by laboratory studies (Dunn et al, 1991;Hamernik and Qiu, 2001;Lei et al, 1994;Hamernik et al, 1974) and by epidemiological studies (Sulkowski and Lipowczan, 1982;Thiery and Meyer-Bisch, 1988).…”

Section: Introductionmentioning

confidence: 99%

Kurtosis corrected sound pressure level as a noise metric for risk assessment of occupational noises

Goley

Song

Kim

2011

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

Current noise guidelines use an energy-based noise metric to predict the risk of hearing loss, and thus ignore the effect of temporal characteristics of the noise. The practice is widely considered to underestimate the risk of a complex noise environment, where impulsive noises are embedded in a steady-state noise. A basic form for noise metrics is designed by combining the equivalent sound pressure level (SPL) and a temporal correction term defined as a function of kurtosis of the noise. Several noise metrics are developed by varying this basic form and evaluated utilizing existing chinchilla noise exposure data. It is shown that the kurtosis correction term significantly improves the correlation of the noise metric with the measured hearing losses in chinchillas. The average SPL of the frequency components of the noise that define the hearing loss with a kurtosis correction term is identified as the best noise metric among tested. One of the investigated metrics, the kurtosis-corrected A-weighted SPL, is applied to a human exposure study data as a preview of applying the metrics to human guidelines. The possibility of applying the noise metrics to human guidelines is discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Kurtosis corrected sound pressure level as a noise metric for risk assessment of occupational noises

Goley

Song

Kim

2011

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

show abstract

“…Threshold was defined to be one-half step size (2.5 dB) below the lowest intensity that showed a response consistent in amplitude and latency with the responses seen at higher intensities. Additional details of the AEP experimental methods may be found in Ahroon et al (1993).…”

Section: A Auditory Evoked Potentialmentioning

confidence: 99%

“…The transients typically have variable peak intensities, durations and rates of occurrence making the noise environment difficult to quantify or to characterize for hearing conservation purposes. There is considerable data available indicating that such complex noise exposures pose a greater hazard to hearing than does a purely G noise exposure of equivalent energy (Lataye and Campo, 1996;Thiery and Meyer-Bisch, 1988;Passchier-Vermeer, 1983;Sulkowski, 1983;Ahroon et al, 1993;Dunn et al, 1991). Current international standards for exposure to noise (ISO-1999(ISO- , 1990) rely solely on an energy metric and may thus not protect large numbers of workers employed in complex noise environments from acquiring a noise-induced hearing loss (NIHL).…”

Section: Introductionmentioning

confidence: 99%

The value of a kurtosis metric in estimating the hazard to hearing of complex industrial noise exposures

Qiu

Hamernik

Davis

2013

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

A series of Gaussian and non-Gaussian equal energy noise exposures were designed with the objective of establishing the extent to which the kurtosis statistic could be used to grade the severity of noise trauma produced by the exposures. Here, 225 chinchillas distributed in 29 groups, with 6 to 8 animals per group, were exposed at 97 dB SPL. The equal energy exposures were presented either continuously for 5 d or on an interrupted schedule for 19 d. The non-Gaussian noises all differed in the level of the kurtosis statistic or in the temporal structure of the noise, where the latter was defined by different peak, interval, and duration histograms of the impact noise transients embedded in the noise signal. Noise-induced trauma was estimated from auditory evoked potential hearing thresholds and surface preparation histology that quantified sensory cell loss. Results indicated that the equal energy hypothesis is a valid unifying principle for estimating the consequences of an exposure if and only if the equivalent energy exposures had the same kurtosis. Furthermore, for the same level of kurtosis the detailed temporal structure of an exposure does not have a strong effect on trauma.

show abstract

“…These SLMs commonly use condenser microphones to detect the noise signals, and take Aweighted equivalent sound pressure level (SPL), L Aeq , as criterion to evaluate the noise exposure levels. However, a number of studies showed that the impulsive noise and the complex noise could not be accurately rated by the EEH [2,3]. Furthermore, L Aeq could not reflect that frequency discrepancy in hearing loss evaluation.…”

Section: Introductionmentioning

confidence: 99%

“…Typical workplaces are often subjected to a complex noise environment in which high-level impulsive noise mixed with continuous Gaussian noises are embedded [1]. A number of animal studies showed that interaction effect between impulsive and broadband noises may actually exacerbate the NIHL [2]. For example, an exposure to a complex noise was observed to produce a much greater permanent threshold shift (PTS) and more extensive hair cell losses than an exposure to only an energy equivalent continuous or impulsive noise alone would have caused.…”

Section: Introductionmentioning

confidence: 99%

Measurement of field complex noise using a novel acoustic detection system

2014

View full text Add to dashboard Cite

Abstract-This paper represents our recent experimental measurement study of the complex noise in industrial fields, using a novel acoustic detection system and wavelet transform algorithms. Noise induced hearing loss (NIHL) continues to be one of the most prevalent occupational hazards in the United States. Number of research on NIHL showed a complex noise could produce more hearing loss than an energy-equivalent continuous or impulsive noise alone. Many workplaces in varied industries are subjected to the high level complex noise (i.e., high-level impulsive noise mixed with continuous Gaussian noise). The current noise measurement guidelines and devices (e.g., conventional sound level meters) are based on the equal energy hypothesis (EEH), which states that loss of hearing by exposure to noise is proportional to the total acoustic energy of the exposure. However, the EEH does not accurately rate the impulsive noise and the complex noise. Therefore, the conventional sound level meter may not be able to accurately assess the complex noise in industrial fields. In this project, a new waveform profile based noise measurement system has been developed for evaluation of the high level complex noise in industrial fields. The system consists of four ½" condenser microphones, and it can simultaneously detect and record four waveforms of the complex noise with high sampling rate (125 KHz). In addition, a wavelet transform based signal analysis algorithm has been modified and implemented to characterize the complex noise. Pilot field measurements have been conducted in selected local coal mining fields (e.g., wet coal preparation plant and dry coal handling plant) using the developed system. The preliminary results showed that the system successfully detected and recorded waveforms of complex noise in industrial fields. The modified algorithm can decomposed the complex noise signals and display the detailed features in the time-frequency joint domain. The key parameters of complex noise can be determined, and the hazardous complex noise in industrial fields can be identified. In addition, when measuring the equivalent A-weighted averaged sound pressure level, the developed system is comparable to a conventional sound level meter.

show abstract

Complex noise exposures: An energy analysis

Cited by 50 publications

References 0 publications

Kurtosis corrected sound pressure level as a noise metric for risk assessment of occupational noises

Kurtosis corrected sound pressure level as a noise metric for risk assessment of occupational noises

The value of a kurtosis metric in estimating the hazard to hearing of complex industrial noise exposures

Measurement of field complex noise using a novel acoustic detection system

Contact Info

Product

Resources

About