Use Of Ear Protectors Research Articles

Signal detection in industrial noise: effects of noise exposure history, hearing loss, and the use of ear protection.

The detection of one-third octave signals superimposed on backgrounds of steady-state and intermittent industrial noise of 84 dBA was investigated for observers with normal hearing or moderate to severe noise-induced hearing loss (NIHL). Variables included age, noise exposure history, configuration of the audiogram and the wearing of insert hearing protectors. Detection thresholds were obtained binaurally over headphones using a two- interval forced-choice procedure. For unprotected listening all observers showed a masked threshold of about 80 dBA for a one-third octave band cented at 3.15 kHz. Neither variation in noise exposure history nor configuration of the audiogram were significant factors. Using insert protectors in noise, observers with normal hearing showed an advantage on average of 3 dB. Those with NIHL gave masked detection thresholds greater than 100 dBA. Detection of a one-third octave band centred at 1 kHz by hearing-impaired observers with mild to moderate loss at 1 kHz was similar to that for normal observers. A model of the detection process was developed and evaluated.

Noise in small industry.

Exposure to noise, the availability and the use of ear protectors, and the adequacy of the medical surveillance of noise-exposed workers were surveyed in the small industry of Finland in order to provide information for the development of occupational health care. One hundred workplaces were chosen by random sampling to represent the small industry (personnel 5-49) in the province of Uusimaa. About a third (32%) of the workers (n = 1181) were exposed to a noise level of at least 85 dB (leq) when at work. However, the prevalence of noise exposure varied greatly, from 3 to 82% according to the type of industry. One in five workers exposed to noise was under periodic medical surveillance (audiogram). Ear protectors were available to about a half of the workers. Fewer than half of the workers with ear protectors at their disposal actually used them. Preventive measures are discussed with respect to noise-induced hearing loss among the personnel working in small industry.

The use of ear protectors in the paper industry

1. The objective of the study The main purpose of the study was the collection of data which could be used to promote and motivate the use of ear protectors in the paper industry. The results of the study should be especially useful when instructing workers on the use of ear protectors, and when attempting to improve the design and construction of ear protectors. 2. Methods and subjects Data concerning 237 workers from a paper mill in southern Finland was collected by means of a questionnaire. 3. Results 104 workers claimed to suffer from diagnosed hearing loss. The frequency of hearing loss reported particularly increased after 10–19 years of working in noisy surroundings, this regardless of the age of the workers. The frequency of hearing loss among workers exposed to a noise level of 95–100 dB(A) was somewhat higher than among workers exposed to either 85–90 dB(A) or 90–95 dB(A); the difference, however, was not statistically significant. The 47 workers who used ear cups experienced, e.g. following inconveniences caused by the ear cups: the cups press, they cause perspiration, they make it difficult to hear speech. 172 workers used ear plugs. The worst disadvantage to using ear plugs was the hygienic danger of wearing dirty ear plugs. As many as 183 workers occasionally worked without ear protectors. The following reasons for not using protectors were given: slight risk of hearing loss (44 %); difficult to hear instructions (42 %); perspiration (34 %); neglected putting them on (26 %); protectors forgotten somewhere (25 %). 4. Conclusions More attention must be paid to instructing workers on the proper use of ear protectors. They must be better informed about the risk of hearing loss when they use protectors only some of the time. More attention must also be paid to the selection, fitting and maintenance of ear protectors.

Vibration Syndrome in the Etiology of Occupational Hearing Loss

The connection of noise-induced permanent threshold shift (NIPTS) and the vasospastic component of vibration syndrome was studied. The purpose of the longitudinal study was to detect whether vibration-induced circulatory disturbances (VWF) in the fingers are generalized and whether VWF indicates increased hearing loss in lumberjacks. The lumberjacks studied (N = 72 in 1972; 203 in 1978) were classified according to history of VWF, exposure time, age and the use of ear protectors. The hearing level at 4,000 Hz was used to indicate NIPTS. The personal exposure to noise was Leq 96–103 dB (A). A statistically significant hearing difference was found between lumberjacks with and those without VWF. The findings indicate that circulatory disturbances in the fingers are connected to occupational hearing loss; thus, the harmful effects of local vibration are not restricted to the hand-arm system. The proposed etiological mechanism for NIPTS may be similar to the one proposed for VWF: chronic overexcitation of the ...

Modifying Earplug Wearing Behavior by Behavior Modification Techniques:

A token economy system for, workers and a managerial intervention were developed in an industrial setting to modify the use of ear protectors. The token economy increased workers' use of ear protectors during work shifts, while new managerial standards maintained the level of earplug usage reached during the token economy intervention. As a result of the intervention program, earplug usage reached an operant level of about 95%. This remained stable throughout the follow-up period during which the new managerial stand was in effect. Theoretical and applied implications of organizational maintenance strategies are dismissed in view of the demonstrated effectiveness of the present intervention.

Promoting increased use of ear protectors in noise through information feedback : Zohar, D., Cohen A. and Azar, N.Human Factors, Feb 1980, 22. 1, 69–79

Promoting increased use of ear protectors in noise through information feedback : Zohar, D., Cohen A. and Azar, N.Human Factors, Feb 1980, 22. 1, 69–79

Promoting Increased Use of Ear Protectors in Noise Through Information Feedback

Promoting Increased Use of Ear Protectors in Noise Through Information Feedback

Promoting increased use of ear protectors in noise through information feedback.

Workers in a noisy department of a metal fabrication plant took hearing tests before and at the end of their workshifts to ascertain the extent of temporary hearing losses that occurred with and without earplugs being worn. This information was fed back to individual workers as a means for motivating greater use of ear protectors issued for hearing conservation purposes. Subsequent observations of earplug users in this department for 5 months showed a steady increase, attaining a level of 85 -90%. No more than 10% of the workers in another noisy department in the same plant, serving as a control group, wore earplugs over the same 5-month period after being given a standard lecture on hearing conservation in noise, later augmented by disciplinary threats. The effectiveness of the feedback technique in promoting earplug usage was explained as a two-stage process involving individual reinforcement, and subsequent group adoption of new norms for accepted behavior.

Aspects on personal noise protection.

Two groups of noise-exposed workers were compared with respect to their use of ear protectors. One group had a severe, noise-induced hearing loss; the other group had normal hearing. Both groups were composed of workers of similar age and total duration noise-exposure. It was found that those with normal hearing had used ear protectors considerably more than those with severe hearing loss. Interestingly, quite a few workers had normal hearing in spite of working in noise for many years without ear protectors. Also, quite a few workers had a severe hearing loss in spite of frequent use of ear protectors. The reasons for not using ear protectors were analysed as also was the condition of the protectors and frequency with which they were replaced. Plastic ear plugs were preferred by 44%, vinyl foam ear plugs by 26%, fibreglass down by 18%, and ear muffs by 11% of the workers. In general, the condition of the ear protectors was good. Surprisingly, one-third of the workers did not use ear protectors, many of them because they had not realized that the environment they worked in had a noise intensity level above the injury risk level.

Arbeitsplatzwechsel bei Lärmberuf

Nowadays noise in industry cannot be eliminated by technical means alone. Therefore, exposed workers have to wear an ear protector to prevent the occurrence of deafness caused by professional noise. Patients with chronic otitis media and permanent or intermittent otorrhea should avoid the prolonged use of ear protectors. On principle, such patients are not allowed to work in a noisy environment (inaptitude for noisy employment/change of occupation) unless the contraindication for use of ear protectors can be eliminated by therapeutic means (such as operation).

Techniques of noise abatement: control at the receiver

To protect the receivers, the human ears, from exposure to excessive noise the complete range of mechanical anti-noise ear protectors is outlined. The ear plugs, semi-inserts, ear muffs, and helmets are explained with respect to basic desirable features of an ideal ear protector. These ear protectors are ranked and compared. Finally, effective use of ear protectors is described.

A Discrimination Test for Nonspeech Signals

Coal miners, while they are exposed to excessively high levels of noise, must be able to listen for roof talk or sounds created by stress release in the mine roof, which is indicative of an imminent cave-in. Any device that interferes with the ability of the miner to hear these roof-talk signals would constitute a safety hazard to the miner. It has been suggested that the use of ear protectors might constitute such a hazard. A set of roof-talk tapes has been assembled to assess this possible hazard. These consist of one listening tape for training subjects in listening to roof talk and a set of test tapes for testing subjects' abilities to identify the presence of roof-talk warning signals in the presence of varying amounts of noise. Six subjects were tested using these roof-talk test tapes and speech discrimination materials. Aspects of test development and test results will be discussed in detail. [This research was supported by contract with the U. S. Bureau of Mines.]

Exposure to Noise in the Textile Industry of the U.A.R.

Abstract The high prevalence of hearing loss among a sample of 117 weavers in the United Arab Republic (U.A.R.) initiated this study. Exposure to noise was evaluated in eight weaving departments, as well as in other departments in a textile plant which has been in operation for over forty years. Levels as high as 103 dBA and an average of 98 dB, for the region 1200-4800 hertz, were encountered. Noise levels were higher in the departments where the looms operated at comparatively high speed. Noise characteristics also varied with the design of the looms for different weaving operations, e.g. normal, wool, or jackar weaving. Comparison of the noise levels measured in this investigation, with the criteria recommended for hearing conservation, pointed out the need for a hearing conservation program. A control program is described, which consists mainly of the installation of sound absorbing material in the weaving departments and the use of ear protectors. Other possible control measures are also described.

Design factors and use of ear protection.

The problems of protecting the ear against hazardous noise are the subject of a general review, supported where relevant by data from the authors9 own researches. Ear protectors are classified into two main types−plugs and muffs—and the general principles of their function and limitations are stated. Examples of representative ear protectors are given in more detail, with particular respect to their relative merits and pure-tone attenuation characteristics. The effects of earplugs on speech communication are considered and the relationships between pure-tone attenuation and protection against continuous noise are discussed in some detail. The results of temporary threshold shift (T.T.S.) reduction studies of the efficiency of V.51R and Selectone-K earplugs in protecting against reverberant and non-reverberant impulsive noises are presented. The design requirements of ear protectors and some of the problems created by them are also outlined.

Evaluation of Air Force Hearing Data

This program was intended to evaluate the effectiveness of the Air Force Hearing Conservation Program in light of several years experience. More than 82 000 audiometric tests on over 58 000 people were transferred to punched cards, processed by a large digital computer, and analyzed. In spite of a large amount of missing, illegible, or otherwise unusable data, it was possible to derive much useful information from the Hearing Data Repository. Benefits from the use of ear protection were not apparent, which leads one to question if people really use ear protection when they should or if they use it properly. The information in the repository on noise exposure, past and present, was not in a form permitting more meaningful interpretations. Further, it was found that the sample used had poorer hearing than a sample of the general population used as a reference, and one would want to derive an Air Force reference. [This program was sponsored by the School of Aerospace Medicine.]

Correlation of industrial noise exposures with audiometric findings.

Abstract A noise exposure profile system was developed following study of noise exposures and hearing losses among Dow employees. Four categories of severity were established ranging from quiet job (profiled “A”) to extremely noisy jobs (profiled “D”). The possible effects and interactions of noise exposure, age, time on the job, previous noise exposure, ear pathology, and the use of ear protection were studied. There was evidence that men working in jobs profiled “A” and “B” showed more hearing loss than was expected for normal ageing. Men in jobs profiled “C” and “D” showed hearing losses greater than those expected from ageing.

Hearing Loss among Air Force Flight-Line Personnel

As a part of an investigation on the hearing acuity of Air Force personnel, pure-tone audiometric tests and job, noise, and medical history questionnaires were administered to 996 Bergstrom AFB flight-line personnel. For 16 Air Force Specialty groups mean hearing losses (better and worse ear) at 4000 cps ranged from 1.8 db to 20.7 db re audiometer zero. Worse-ear hearing losses at 3000 cps and at 4000 cps in nine Air Force Specialty groups (N=854) did not differ significantly from one group to another. Significant positive correlation was found when 4000-cps hearing loss was correlated with age and when 4000-cps hearing loss was correlated with length of noise exposure. However, when the positive hearing loss vs exposure correlation was adjusted for the positive relationship between age and exposure, no remaining statistically significant relationship existed between 4000-cps hearing loss and length of noise exposure. Infrequent use of ear protection is interpreted as evidence indicating a real need for effective noise and ear-protection indoctrination of personnel exposed to high-level on the job noise.