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Item Noise characteristics of grass-trimming machine engines and their effect on operators.(2009-04-06) Mallick, Zulquernain; Badruddin, Irfan Anjum; Khaleed Hussain, M T; Salman Ahmed, N J; Kanesan, JeevanOver the last few years, interaction of humans with noisy power-driven agricultural tools and its possible adverse after effects have been realized. Grass-trimmer engine is the primary source of noise and the use of motorized cutter, spinning at high speed, is the secondary source of noise to which operators are exposed. In the present study, investigation was carried out to determine the effect of two types of grass-trimming machine engines (SUM 328SE and BG 328) noise on the operators in real working environment. It was found that BG-328 and SUM-328SE produced high levels of noise, of the order of 100 and 105 dB(A), respectively, to which operators are exposed while working. It was also observed that situation aggravates when a number of operators simultaneously operate resulting in still higher levels of noise. Operators should be separated 15 meters from each other in order to avoid the combined level of noise exposure while working with these machines. It was found that SPL, of the grass-trimmer machine engines (BG-328 and SUM-328SE), were higher than the limit of noise recommended by ISO, NIOSH, and OSHA for an 8-hour workday. Such a high level of noise exposure may cause physiological and psychological problems to the operators in long run.Item A national project to evaluate and reduce high sound pressure levels from music.(2009-04-06) Ryberg, Johanna BengtssonThe highest recommended sound pressure levels for leisure sounds (music) in Sweden are 100 dB LAeq and 115 dB LAFmax for adults, and 97 dB LAeq and 110 dB LAFmax where children under the age of 13 have access. For arrangements intended for children, levels should be consistently less than 90 dB LAeq. In 2005, a national project was carried out with the aim of improving environments with high sound pressure levels from music, such as concert halls, restaurants, and cinemas. The project covered both live and recorded music. Of Sweden's 290 municipalities, 134 took part in the project, and 93 of these carried out sound measurements. Four hundred and seventy one establishments were investigated, 24% of which exceeded the highest recommended sound pressure levels for leisure sounds in Sweden. Of festival and concert events, 42% exceeded the recommended levels. Those who visit music events/establishments thus run a relatively high risk of exposure to harmful sound levels. Continued supervision in this field is therefore crucial.Item Distortion product otoacoustic emissions in an industrial setting.(2009-04-06) Korres, George S; Balatsouras, Dimitrios G; Tzagaroulakis, Antonis; Kandiloros, Dimitris; Ferekidou, Elisabeth; Korres, StavrosDistortion product otoacoustic emissions (DPOAEs) is an objective sensitive test of cochlear function. The aim of this study was the evaluation of noise-induced hearing loss in a group of industrial workers, using this method in conjunction with standard puretone audiometry (PTA). One hundred and five subjects (210 ears) were included in the study. PTA, tympanometry, and DPOAEs were performed. Results were analyzed using a mixed analysis of variance model, and compared with the data of 34 normal persons of similar age and sex. We found statistically significant lower DPOAE levels in the noise-exposed group than in the control group. Additionally, the effect of frequency was significant, indicating that amplitude varied across frequency, with lower responses observed at 4 and 6 kHz, and maximum response found at 2 kHz. PTA showed a statistically significant effect of Group, owed to elevated puretone thresholds in the noise-exposed subjects, but a Frequency main effect was not found, although the interaction between Frequency and Group was statistically significant, as well as the interaction between Frequency and Ear. A main effect for Ear was found only in puretone thresholds, due to better thresholds in the left ears of the subjects, and not in DPOAE measurements. DPOAE levels were selectively affected at the higher frequencies, whereas puretone thresholds were affected at all frequencies. Direct comparison of the number of significantly affected ears between the two methods at 1, 2, and 4 kHz showed statistically significant differences at all comparisons, with more ears affected in PTA in comparison with DPOAEs at 4 kHz, whereas more ears were affected in DPOAEs at the lower frequencies (1 and 2 kHz). Therefore, it may be concluded that DPOAEs and PTA are both sensitive methods in detecting noise-induced hearing loss, with DPOAEs tending to be more sensitive at lower frequencies.Item Chronic exposure of rats to occupational textile noise causes cytological changes in adrenal cortex.(2009-04-06) Oliveira, Maria Joao R; Monteiro, Mariana P; Ribeiro, Andreia M; Pignatelli, Duarte; Aguas, Artur PChronic exposure to industrial noise and its effects on biological systems. Occupational exposure to noise may result in health disorders. Our aim was to evaluate the effects of chronic exposure to high-intensity noise of textile industry cotton rooms on the adrenal morphology. The environmental noise of a cotton-mill room from a large textile factory of Northern Portugal was recorded and reproduced by an adopted electroacoustic setup in a sound-insulated animal room where the rats were housed. The sounds were reproduced at the original levels of approximately 92 dB, which was achieved by equalization and distribution of sound output in the room. Wistar rats were submitted to noise exposure, in the same time schedule as employed in textile plants. After one, three, five, and seven months, the adrenals were collected and analyzed by light microscopy. Analyzed by multivariate analysis of variance and post hoc Bonferroni correction for multiple comparisons of the means between the groups. Noise exposure induced time-dependent changes in adrenal cortex, with decrease of zona fasciculata (ZF) and increase of zona reticularis volumes, together with a significant depletion of lipid droplet density in ZF cells of exposed rats, in comparison to control rats. Chronic exposure of rats to textile industry noise triggers cytological changes in the adrenals that suggest the existence of a sustained stress response.Item Noise sensitivity and subjective health: Questionnaire study conducted along trunk roads in Kusatsu, Japan.(2009-04-06) Kishikawa, Hiroki; Matsui, Toshihito; Uchiyama, Iwao; Miyakawa, Masamitsu; Hiramatsu, Kozo; Stansfeld, Stephen AA questionnaire study was conducted in a residential area along trunk roads in Kusatsu, Japan, in order to investigate the association between noise exposure, noise sensitivity, and subjective health. Subjective health of the respondents was measured by the General Health Questionnaire (GHQ-28) which yields the total score as an index of psychiatric disorder and four subscales. Noise sensitivity was measured by the improved version of the Weinstein's noise sensitivity scale named WNS-6B. The original WNS and a single question directly asking respondents' noise sensitivity were also applied to confirm the validity of the WNS-6B for investigating the effects of road traffic noise on subjective health. Respondents were also asked about disturbances of daily life due to noise exposure to find the cause of the health effects. Three hundred and twenty three answers were entered into the analysis. Applying the WNS-6B as the noise sensitivity measurement scale, a significant correlation was found between subjective health and noise exposure in the noise-sensitive group, while no significant correlation was observed in the insensitive group. These results suggest that the adverse health effects may exist especially in the sensitive group. Application of the other two noise sensitivity measurement scales showed no significant relationship either in the sensitive group or in the insensitive group. The WNS-6B would have greater advantage for detecting adverse health effects than the other scales. Furthermore, the primary cause of the adverse health effect was investigated. The results of the analysis indicated that the adverse health effects were mainly caused by the sleep disturbance and were not caused by hearing interference.Item Self-reported noise exposure as a risk factor for long-term sickness absence.(2009-04-06) Clausen, Thomas; Christensen, Karl Bang; Lund, Thomas; Kristiansen, JesperSelf-reported noise exposure is on the rise in Denmark. Little is known, however, about the social consequences, including sickness absence, of noise exposure. The aim of this paper was to investigate the association between self-reported noise exposure and long-term sickness absence. The association was investigated using the Cox proportional hazards model to analyze outcomes in Danish register data on the basis of Danish survey data (5357 employees aged 18-69 in 2000). The analyses showed that self-reported noise exposure was significantly associated with long-term sickness absence for both men and women when adjusting for demographic factors and health behavior. After further adjustment for physical workload at work the association between noise exposure and sickness absence disappeared for women, but not for men. Men that reported to be exposed to loud noise between one-quarter and three-quarters of their time at work had an increased risk of 43% (CI: 10-85%) for sickness absence of two weeks or longer compared to men that reported never to be exposed to loud noise. Men that reported to be little/rarely exposed to loud noise had an increased risk of 37% (CI: 7-76%). Men that reported to be exposed to loud noise more than three-quarters of their time at work did not have an increased risk of sickness absence. This latter result might be due a healthy worker effect and/or more frequent use of hearing protection in this group. Along with evidence from previous studies these results provide further support for an association between occupational noise exposure and sickness absence.Item Shooting habits of U.S. waterfowl hunters.(2009-01-07) Stewart, Michael; Borer, Sarah E; Lehman, MarkExposure to high-intensity impulse noise from the recreational use of firearms is a common cause of noise-induced hearing loss (NIHL). Although recreational firearm users who shoot firearms without proper hearing protection are at risk for NIHL, a specific subgroup involved in hunting waterfowl may also be at risk due to their particular shooting habits. The goal of the present study was to investigate the shooting habits of this particular group of U.S. recreational firearm users. A 23-item written survey was sent to waterfowl hunting club members regarding their shooting behaviors, use of hearing protective devices (HPDs), and auditory status. Results indicated that waterfowl hunters in this study typically used large bore semiautomatic shotguns, did not consistently utilize HPDs during target practice or hunting and were exposed to multiple, unprotected shots during the past waterfowl season. Most subjects reported hunting in reverberant acoustic environments (hunting blinds). This group of recreational firearm users also reported high incidences of hearing loss and tinnitus. Information provided by this study may help hearing conservationists and hearing healthcare providers understand and better educate these shooters regarding the risk of acquiring NIHL.Item Reliability of audiometric thresholds obtained with insert earphones when used by certified audiometric technicians.(2009-01-07) Bell-Lehmkuhler, Barbara; Meinke, Deanna K; Sedey, Allison; Tuell, CassieClinical audiologists and audiometric equipment manufacturers have embraced the clinical use of insert earphones; however, their use in audiometric testing in occupational hearing loss prevention programs has been limited. This study was undertaken to research whether certified audiometric technicians without practical hands-on training could reliably use insert earphones when compared to a clinically experienced audiologist. Hearing thresholds were obtained on 60 human ears by six certified audiometric technicians using insert earphones for the first time. Technician-acquired audiometric thresholds were compared to thresholds obtained under the same conditions by a clinical audiologist experienced in the use of the insert earphones. Statistical analyses of audiometric thresholds were performed to investigate the relationships between audiometric threshold values at each frequency obtained by certified technicians vs. the audiologist. These relationships were examined for the group as a whole as well as when ear tip size and earphone insertion depth varied between the audiologist and the technicians. No significant differences (p > .01) were found between mean group thresholds at any of the test frequencies (500-8000 Hz). Mean group thresholds differed by < 1.2 dB. Pearson Product-Moment correlation (PPMC) coefficients suggested that thresholds obtained by the audiometric technician were highly correlated with those obtained by the audiologist. There were no significant threshold differences (p > .01) even when the audiologist and technicians varied in their selection of ear tip size or in the amount of insertion depth achieved. This study suggests that CAOHC-certified audiometric technicians can reliably use insert earphones without practical training when testing in quiet environments by reading the earphone package directions provided by the manufacturer.Item Strategic and tactical thinking in the hearing conservation mindset: a military perspective.(2009-01-07) Ohlin, DougItem The hearing conservation amendment: 25 years later.(2009-01-07) Suter, Alice HIt has been twenty-five years since the final version of the Hearing Conservation Amendment was issued by the Occupational Safety and Health Administration in the U.S. Department of Labor. Since that time, some things have changed and others have stayed exactly the same. Certainly the noise-exposed workforce is more knowledgeable about the hazards of noise, and the use of hearing protection devices (HPDs) has greatly increased. There have been significant strides in the technology for measuring noise and for protecting hearing through HPDs. But there is considerable room for improvement. Some of the noise regulation's provisions are embarrassingly outdated, some are in dire need of improvement, and others, such as the requirements for engineering noise control, are not being enforced. Sadly, there seems to be little progress in reducing overall noise exposure levels. What needs to be done at this point is a major overhaul of the noise regulation: recommitment to engineering noise control; reduction of the permissible exposure limit (PEL) to 85 dBA; a shift to the 3-dBA exchange rate; and a nationwide assessment of hearing loss in American workers to determine the effectiveness of current hearing conservation measures to identify and address the weaknesses in programs and regulations.Item Attitudes of college music students towards noise in youth culture.(2009-01-07) Chesky, Kris; Pair, Marla; Lanford, Scott; Yoshimura, EriThe effectiveness of a hearing loss prevention program within a college may be dependent on attitudes among students majoring in music. The purpose of this study was to assess the attitudes of music majors toward noise and to compare them to students not majoring in music. Participants ( N = 467) filled out a questionnaire designed to assess attitudes toward noise in youth culture and attitudes toward influencing their sound environment. Results showed that students majoring in music have a healthier attitude toward sound compared to students not majoring in music. Findings also showed that music majors are more aware and attentive to noise in general, likely to perceive sound that may be risky to hearing as something negative, and are more likely to carry out behaviors to decrease personal exposure to loud sounds. Due to these differences, music majors may be more likely than other students to respond to and benefit from a hearing loss prevention program.Item Hearing loss in veterans and the need for hearing loss prevention programs.(2009-01-07) Saunders, Gabrielle H; Griest, Susan ECurrently, there are more than 445,000 veterans receiving compensation for hearing loss associated with military service, and 395,000 receiving compensation for service-related tinnitus. In addition to compensation payments, service-related hearing disorders cost the US Department of Veterans Affairs in terms of provision of hearing aids, hearing aid-related services, and clinical services at its 220 facilities nationwide. It is imperative that hearing conservation among military personnel and veterans be addressed. In this paper, we describe the rationale for and the development of a multimedia Hearing Loss Prevention Program aimed at preventing the progression of hearing loss among veterans associated with social, recreational, and nonmilitary occupational noise exposure. The program was developed based on the principles outlined in the Health Belief Model of Rosenstock (1966) and the Health Promotion Model of Pender et al. (2002).Item Elementary school children's knowledge and intended behavior toward hearing conservation.(2009-01-07) Chen, Hsiaochuan; Huang, Minju; Wei, JiuhunhwaThe purposes of the study were to investigate children's knowledge about hearing conservation, the types of protective behaviors they would adopt in noise, the agreement between children's knowledge and intended behaviors in hearing protection, and reasons why they would not take any protective action in noise. A questionnaire was administered to 479 fourth and fifth graders in their school classrooms. Results indicated that children scored low (62.0%) on this hearing conservation questionnaire. They scored the highest in strategies of hearing protection (69.9%), followed by their knowledge in general hearing health (62.6%) and noise hazards (49.6%). Only 55% of children knew that hearing protective devices could protect them against noise. Approximately 28% of children did not intend to adopt any protective behavior in noise and the major reason for this was lack of knowledge. Children's knowledge and their noise protective behavior were correlated ( P < .05). However, possessing knowledge did not guarantee that children would adopt such behaviors when they were exposed to loud sounds. It is important to increase children's knowledge about hearing protection and hazardous noise as well as to encourage actual protective actions.Item Principles and application of educational counseling used in progressive audiologic tinnitus management.(2009-01-07) Henry, James A; Zaugg, Tara L; Myers, Paula J; Kendall, Caroline J; Turbin, Mitchel BExposure to loud sounds is a common cause and exacerbater of tinnitus - a troubling auditory symptom that affects millions of people worldwide. Clinical research at the National Center for Rehabilitative Auditory Research has resulted in a clinical model of tinnitus management referred to as Progressive Audiologic Tinnitus Management (PATM). The model involves five hierarchical levels of management: Triage, Audiologic Evaluation, Group Education, Tinnitus Evaluation, and Individualized Management. Counseling by audiologists and, as needed, mental health providers, is a key component of PATM. This style of counseling focuses less on didactic informational counseling; instead, counseling is used for facilitating patients' learning to adjust to the disturbing auditory symptom by successfully employing tools from two powerful skillsets for self-management of chronic tinnitus - the therapeutic uses of sound and techniques from cognitive-behavioral psychology. This article provides an overview of the methods of counseling used with PATM and provides details concerning the overarching principles of collaborative adult learning that are believed to be most important in facilitating self-management by patients who complain of tinnitus.Item Synergistic ototoxicity due to noise exposure and aminoglycoside antibiotics.(2009-01-07) Li, Hongzhe; Steyger, Peter SAcoustic exposure to high intensity and/or prolonged noise causes temporary or permanent threshold shifts in auditory perception, reflected by reversible or irreversible damage in the cochlea. Aminoglycoside antibiotics, used for treating or preventing life-threatening bacterial infections, also induce cytotoxicity in the cochlea. Combined noise and aminoglycoside exposure, particularly in neonatal intensive care units, can lead to auditory threshold shifts greater than simple summation of the two insults. The synergistic toxicity of acoustic exposure and aminoglycoside antibiotics is not limited to simultaneous exposures. Prior acoustic insult which does not result in permanent threshold shifts potentiates aminoglycoside ototoxicity. In addition, exposure to subdamaging doses of aminoglycosides aggravates noise-induced cochlear damage. The mechanisms by which aminoglycosides cause auditory dysfunction are still being unraveled, but likely include the following: 1) penetration into the endolymphatic fluid of the scala media, 2) permeation of nonselective cation channels on the apical surface of hair cells, and 3) generation of toxic reactive oxygen species and interference with other cellular pathways. Here we discuss the effect of combined noise and aminoglycoside exposure to identify pivotal synergistic events that can potentiate ototoxicity, in addition to a current understanding of aminoglycoside trafficking within the cochlea. Preventing the ototoxic synergy of noise and aminoglycosides is best achieved by using non-ototoxic bactericidal drugs, and by attenuating perceived noise intensity when life-saving aminoglycoside therapy is required.Item A field investigation of hearing protection and hearing enhancement in one device: for soldiers whose ears and lives depend upon it.(2009-01-07) Casali, John G; Ahroon, William A; Lancaster, Jeff AOperational hearing protection and maintenance of audibility of signals and speech are considered force multipliers in military operations, increasing Soldier survivability and lethality. The in-field research described in this paper was conducted to examine operational performance effects of three different hearing enhancement protection systems (HEPS) that are intended to provide both protection and audibility. The experiment utilized operationally-defined measures in full-scale, simulated combat scenarios with Army ROTC Cadet Soldiers as subjects. The Soldiers' operational performance was evaluated in two missions: reconnaissance and raid (attack on enemy camp). Both missions had substantial hearing requirements, including communications, signal detection/recognition, and distance judgments. Operational performance was measured by objective metrics of Squad performance, including the distances required to detect an enemy insurgent camp under each HEPS, and by subjective metrics, such as the Army's dimensions of combat-related mission success as evaluated by Army Officers who served as training leaders/observers. Other subjective ratings were obtained after each training exercise from both the Officers and the Soldiers, including detailed impressions about each HEPS after extended use. Two of the three HEPS were electronic sound transmission devices (comprising an ambient sound pass-through filtering and amplification circuit): a Peltor Comtac II circumaural headset (NRR=21; 16 dB maximum gain); and a Communications Enhancement Protection System (CEPS) (NRR=29; 36 dB maximum gain). One passive, level-dependent HEPS was used, the yellow end of the Combat Arms Earplug, which provides amplitude-sensitive attenuation that sharply increases when the ambient sound is above about 110 dB (e.g., due to a gunshot), but which provides an NRR of 0 and very little attenuation below 1000 Hz in lower ambient noise levels. In the military mission entailing location of and attack on an enemy camp, the CEPS device resulted in the longest (earliest) average auditory detection distance of the camp (400 feet), followed by the Peltor (233 feet) and then the Combat Arms Earplug (150 feet), in comparison to detection by the unprotected, normal ear at about 220 feet. Commanding officers' ratings of mission performance and overall success slightly favored the electronic HEPS, but these ratings were dependent upon the particular mission undertaken. Ergonomics and usability issues abounded with the electronic HEPS, and the Soldiers' subjective ratings showed variability across all three devices, with device preference depending upon the particular dimension being rated (e.g., comfort vs. hearing ability). Clearly, the results of this in-field experiment demonstrate that more development is needed to achieve the levels of hearing performance and user acceptance from the HEPS that is desirable and needed for combat conditions. In this vein, it is important to note that HEPS designs are continually evolving, and certain upgrades to the three devices evaluated in the late 2006 timeframe of this study have occurred and further evaluations are thus warranted.Item Noise levels in Greek hospitals.(2008-10-17) Tsara, Venetia; Nena, Evangelia; Serasli, Evangelia; Vasileiadis, Vasilis; Matamis, Dimitris; Christaki, PandoraHigh noise levels have been recognized as a serious problem in hospital environments during both night- and daytime, and have been associated with a negative impact on patients' health status. The aim of this study was to measure and detect differences in noise levels between an ICU and a pulmonary ward in two general hospitals in Greece. Methods: Noise measurements were recorded in one-hour intervals using the Cirrus CR: 245/R2 Environmental Noise Analyzer in a 30-bed pulmonary ward and in a 16-bed general ICU for seven consecutive days. Results: Noise levels detected in the ward were significantly lower than those detected in the ICU (52.6 +/- 8.2 dB vs 59 +/- 2.2 dB, P Conclusion: Noise levels measured in the ward and in the ICU were high, significantly exceeding the highest permitted values for hospitals. The latter was more obviously recorded in the ICU.Item High sound pressure levels in Bavarian discotheques remain after introduction of voluntary agreements.(2008-10-17) Twardella, Dorothee; Wellhoefer, Andrea; Brix, Jutta; Fromme, HermannWhile no legal rules or regulations exist in Germany, voluntary measures were introduced to achieve a reduction of sound pressure levels in discotheques to levels below 100 dB(A). To evaluate the current levels in Bavarian discotheques and to find out whether these voluntary measures ensured compliance with the recommended limits, sound pressure levels were measured in 20 Bavarian discotheques between 11 p.m. and 2 a.m. With respect to the equivalent continuous A-weighted sound pressure level for each 30-minute period (L Aeq,30min ), only 4/20 discotheques remained below the limit of 100 dB(A) in all time periods. Ten discotheques had sound pressure levels below 100 dB(A) for the total measurement period (L Aeq,180min ). None of the evaluated factors (weekday, size, estimated age of attendees, the use of voluntary measures such as participation of disc jockeys in a tutorial, or the availability of a sound level meter for the DJs) was significantly associated with the maximal L Aeq, 30min . Thus, the introduction of voluntary measures was not sufficient to ensure compliance with the recommended limits of sound pressure levels.Item Elementary school children's knowledge and intended behavior towards hearing conservation.(2008-10-17) Chen, Hsiaochuan; Huang, Minju; Wei, JiuhunhwaThe purposes of the study were to investigate children's knowledge about hearing conservation, the types of protective behaviors they would adopt towards noise, the agreement between children's knowledge and intended behaviors in hearing protection, and reasons why they would not take any protective action against noise. A questionnaire was administered to 479 4 th and 5 th graders in their school classrooms. Results indicated that children scored low (62.01%) on this hearing conservation questionnaire. They scored the highest in strategies of hearing protection (69.89%), followed by their knowledge in general hearing health (62.56%) and noise hazards (49.65%). Only 55% of the children knew that hearing protective devices could protect them against noise. Approximately 28% of the children did not intend to adopt any protective behavior towards noise and the major reason for this was a lack of knowledge. Children's knowledge and their noise-protective behavior were correlated ( P < 0.05). However, possessing knowledge did not guarantee that children would adopt such behaviors when they were exposed to loud sounds. Hence, it is important to increase children's knowledge about hearing protection and hazardous noise as well as to encourage actual protective actions.Item What do we know about hearing protector comfort?(2008-07-05) Davis, Rickie RThe purpose of the present article is to review comfort studies on hearing protector devices. Comfort is probably the most important dimension for long-term worker acceptance and effective wear of hearing protectors in noise. A short digression has been made to introduce comfort work from the textile and clothing industries where models of comfort have been attempted and comfort research is much more sophisticated. Finally, presented are some recent efforts by NIOSH to examine issues of hearing protector comfort in greater detail. These efforts include a field study of a semi-custom earplug hearing protector.