Julia Doswell Royster

Representative hearing levels by race and sex in North Carolina industry

An extensive sample of North Carolina industrial audiometric test data has been compiled. The sample includes data from several different types of industrial environments, with the size of the industries represented ranging from less than fifty to over eight thousand employees. The total population considered is in excess of 14000 employees. The data are examined using analytical techniques developed over the past six years while investigating the effectiveness of industrial hearing conservation programs. One of the findings is significant differences in the initial hearing threshold levels by race and sex. A second observation is differences by race and sex in the change in haring levels with time It is concluded that the hearing levels of industrial employees differ significantly by race and sex. The differences are of such magnitude that meaningful evaluations of industrial audiometric data bases are not possible unless the race and sex compositions of the population are considered.

Development of a new standard laboratory protocol for estimating the field attenuation of hearing protection devices. Part I. Research of Working Group 11, Accredited Standards Committee S12, Noise

This paper describes research conducted by Working Group 11 of Accredited Standards Committee S12, Noise, to develop procedures to estimate the field performance of hearing protection devices (HPDs). Current standardized test methods overestimate the attenuation achieved by workers in everyday use on the job. The goal was to approximate the amount of attenuation that can be achieved by noise‐exposed populations in well‐managed real‐world hearing conservation programs, while maintaining acceptable interlaboratory measurement variability. S12/WG11 designed two new laboratory‐based protocols for measuring real‐ear attenuation at threshold, with explicit procedures for subject selection, training, supervision, and HPD fitting. After pilot‐testing, S12/WG11 conducted a full‐scale study of three types of earplugs and one earmuff tested by four independent laboratories using both protocols. The protocol designated as ‘‘subject‐fit’’ assessed the attenuation achieved by subjects who were experienced in threshold ...

Age effect hearing levels for a black nonindustrial noise exposed population (NINEP).

A nonindustrial noise exposed population (NINEP) that describes the age effects for a black male and female population has been established. The mean hearing threshold levels for the black NINEP are significantly lower (better hearing) than the previously established mean HTLs for a white NINEP when compared by sex. The availability of the black NINEP now makes it possible to more accurately evaluate a typical industrial noise exposed population (INEP).

Using audiometric data base analysis.

Audiometric data base analysis (ADBA) offers the most direct means of judging the effectiveness of a hearing conservation program (HCP) in preventing occupational hearing loss. However, numerous factors need to be accounted for if the findings are to be meaningful. This paper discusses several parameters known to influence the interpretation of group data statistics in assessing HCP effectiveness. Testing factors that affect the stability of the data base include audiometric techniques, calibration procedures, testing environment, and the motivation and prior experience of the subject. Pertinent population parameters include age, sex, race, current and prior noise exposures, learning effects, and the types of hearing protectors in use. Two case histories are presented to illustrate the application of ADBA techniques. Specific analysis procedures reviewed include comparisons of mean thresholds for selected industrial and nonindustrial populations, rates of change in mean hearing levels over a period of time, baseline and sequential test-retest comparisons, and different threshold shift criteria. The preliminary results of ADBA research being done by the American National Standards Institute (ANSI) S12.12 Working Group are summarized, including desirable criterion ranges for several statistics established by applying them to control data sets.

Important elements and characteristics of hearing conservation programs and determination of their effectiveness

Abstract Results of on-site interviews with industrial personnel involved in hearing conservation programs (HCPs) show common deficiencies in personnel training and program implementation, reducing HCP effectiveness in protecting employees from occupational hearing loss. Audiometric data base analysis (ADBA) provides procedures which allow HCP ineffectiveness to be detected before many employees develop significant noise-induced hearing loss. If HCP procedures are corrected, based on ADBA results, then audiometry serves to prevent hearing loss rather than simply detecting its occurrence. The paper presents criterion ranges for ADBA procedure results as recommended by the ANSI S12.12 Working Group for Evaluation of HCPs.

Hearing protection utilization: Survey results across the USA

Information about the utilization of hearing protection devices (HPDs) has been obtained through on‐site surveys at 219 industrial facilities representative of all regions of the USA. The primary objectives of the study were the identification of problems related to HPD use and the development of a reference manual to guide industrial personnel in achieving maximum benefit from HPDs. The data collected concerned the types of HPD utilization problems encountered. HPD selections offered, criteria considered in choosing HPDs, procedures for fitting/issuing/reissuing, and company policies for furnishing HPDs. User problems identified during the surveys include discomfort, attenuation of warning signals or communication, HPD design limitations, canal irritation, external otitis, wax impaction, and misuse or abuse of HPDs. Problem incidence could be reduced significantly by improved procedures for selection, fitting, issuing, and reissuing HPDs. Administrative problems that were observed include the use of inad...

Chapter 1: Noise Control and Hearing Conservation: Why Do It?

Value of Hearing Conservation................................................................................................6 Quality of Life: The Value of Good Hearing......................................................................6 Quality of Life: Quiet Ears .................................................................................................8 On-the-Job Communication................................................................................................8 Extra-Auditory Effects: Productivity, Lost-Time Accidents, and Related Issues ..............9 Extra-Auditory Effects: Health .........................................................................................11 Worker Attitude.................................................................................................................11

Types and frequencies of abnormal sound levels when using noise dosimeters to establish worker TWAs

The potential contamination of noise dosimetry noise exposure findings as impacted by the following types of artifacts was investigated: thumping of the microphone, moving the microphone around during the sample, hollering directly into the microphone, effects of body reflections, and blowing directly at the microphone. The findings from this investigation support the assumption that contamination of noise dosimetry daily noise exposure results is not of significant concern, at least when using a 5‐dB exchange rate (OSHA). In addition, the detailed histogram records obtained from conducting noise dosimetry noise exposure surveys at five large industrial facilities were reviewed. Of the over 28 000 histogram samples reviewed, less than 14 samples indicated potential contamination from unusual noise sources. In summary, the results of this study confirm what the authors have observed over many years of conducting industrial noise exposure studies using noise dosimetry: contamination of noise dosimetry findi...

Nonoccupational noise exposures and their estimated daily L (eqs.) for general commercial air travel and local bars, restaurants, discos, and socialization establishments

Over a period of several years the authors have collected noise exposure data (N≳150 samples) during normal commercial air travel. The data were collected utilizing noise dosimeters, and an octave‐band analyzer. The resulting noise exposures for air passengers will be presented, including the distribution of the measured A‐weighted sound pressure levels. In addition, as part of regular class assignments, the students of the first author’s Effects Of Noise And Vibration graduate class have collected sound exposure data over several years at popular bars, restaurants, discos, and socialization establishments in the Raleigh, NC area. The noise exposures and sound level distributions from these surveys will also be presented.

Results of the S12 Working Group 11 interlaboratory study to approximate real‐world attenuation of hearing protection devices (HPDs)

Four HPDs, three plugs and one muff, were tested in four labs to identify a protocol that would estimate the real‐world attenuation obtained in field studies of workers in hearing conservation programs. Audiometrically experienced subjects who had never worn HPDs regularly used each device, following the manufacturers’ instructions without any supplemental experimenter training (subject‐fit condition). Subsequently, after the experimenter demonstrated the use of each device, the subject used each HPD again (informed‐user‐fit condition). Attenuation was measured in two trials with each HPD in each instruction condition. Practice within a condition yielded no significant improvement in achieved attenuation. Experimenter instruction significantly increased the attenuation subjects obtained with earplugs (but not earmuffs). The subject‐fit condition approximated the upper quartile of real‐world attenuation, and the range of standard deviations of attenuation across labs was no greater than for the informed‐us...