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Plenary Presentation Summary

John Franks and Lee Hager summarized discussion points after the breakout sessions. Hager presented the summary to the assembled workshop group at the closing Plenary Session.


The following invited presentations provided the basis for discussion.

Noise Control: State of the Art and Unfinished Business

Richard R. James

Robert D. Bruce

Thomas Thunder

Jon Weinstein

Noise Control: Emerging Technologies

Daniel L. Johnson

Richard R. James

Hearing Protectors: State of the Art and Emerging Technologies

Fredrick Lindgren

Dan Gauger

Kevin Michael

John R. Franks


The consensus of the group was that it was necessary to broaden the discussion on noise to include hearing and hearing health issues. Further, the group concluded that it was impossible to limit discussions of hearing health issues to the workplace without consideration of non-occupational exposures.

Regarding engineering controls, it was the consensus of the group that, in general, proven technology exists and is commercially available to control worker exposure to hazardous noise. Participants focused on the underlying reasons for lack of widespread implementation, the barriers to effective hearing loss prevention, and the research agenda necessary to promote the general application of engineering control and protective equipment technologies.

State of the Art in Noise Control

Noise control technology has been developed and applied for industrial machinery and equipment, but implementation of the technology has been limited. Reliance on hearing conservation over engineering as the primary means for exposure control has limited introduction of the technology to some industries, primarily larger corporations who maintain top-down support of health and safety issues. Awareness of and interest in the nature and availability of controls within small and medium sized businesses is limited. Worker exposure to noise is controllable through application of noise control engineering technology and through the proper use of hearing protection devices (HPD). The barriers to effective implementation of current technology need to be identified.

Noise and hearing health issues are difficult to discuss because material indicators have not been adequately defined.
What is effective enforcement of the regulation?
What is an effective Hearing Conservation Program?
What is an effective Noise Control Engineering Program?
What is effectiveness in a hearing protection device (HPD), and how can it be evaluated?

Other findings:
The cost and implications, in economic and social terms of the excess hearing loss that is accruing in this country are not known.
There is no evidence that an infrastructure exists to support a noise control agenda were one to be created.
There is no concept of what would be required in a comprehensive awareness training agenda. That is, who would require training – who would be the target audiences? What topics would be emphasized? How would the effectiveness of such training be assessed?

In summary, the existing hearing conservation paradigm has failed. Current data show hearing loss is progressing at a higher rate than would be expected if existing programs were effective. It is proposed that the essential research agenda be divided into four components:

    1. surveillance,
    2. new technology,
    3. personal protective equipment, and
    4. social marketing.

1. Surveillance Agenda

The Surveillance Agenda consists of a technical surveillance component and an economic surveillance component.

Technical Surveillance

Research on sound exposures is needed. Updated information on the distribution of exposures is required. The current state of exposure monitoring needs to be defined, with the underlying assumptions that define scope of exposure assessment revisited.

A research agenda is proposed that will collect, collate and distribute data on noise exposure including:
Existing MSHA data
Other existing data sets
New data for the 95% of small and medium sized workplaces for which there is no evidence of monitoring having been conducted in any form

Because the country's manufacturing base has changed significantly since previous studies, the impact of this change in workplace demographics on noise exposure distribution needs to be assessed. Equally significant, due in part to the effect of downsizing and outsourcing, the fundamental responsibility and loyalty relationship between employer and employee has changed. The effect of this dynamic on worker exposure to noise and the implications to employers need to be determined.

Part of the technical surveillance effort should be the development and maintenance of a hazardous task inventory, or a compendium of industry-specific noise hazards and noise sources. NIOSH has initiated this effort in the construction trades, but it needs to be expanded to cover all of industry.

Economic Surveillance

The implications of the current trend of hearing loss are unknown. Real costs of maintaining hearing health for the worker, for industry and for society in general need to be identified. Hard costs include items such as:
Workers' Compensation benefits,
health care and the implications for hearing health maintenance under managed health care, and
hearing aid instruments and

Indirect costs related to hearing health merit scrutiny as well. Research into increased risk of accidents due to impaired hearing, high noise levels, or compromised hearing due to use of HPD; productivity analysis; research on communication ability and related implications; and costs of under-realization of career potential (example: US Army hearing requirements for promotion and retention) are important. Worker expectations of maintaining full functionality need recognition. Where our fathers expected to retire after 40 years in industry with compromised hearing, the current generation of workers with its focus on health and wellness will likely not be so accommodating.

A national inventory of hearing critical jobs, both in the public and the private sectors is needed. Part of this research should focus on methods for assessing auditory functionality; methods for determining the hearing-criticality of specific jobs, tasks, and occupations; and methods of accommodation to address workplace accessibility for the hearing impaired.

New Technologies Agenda

A means for distribution of information, especially engineering controls, is needed. A "best practice" compendium and an acoustical materials compendium to collect and distribute existing, proven control technology are possible vehicles. Broad distribution of "buy quiet" specifications to aid the purchase of quiet machines and equipment is another aspect of best practice information distribution. These steps can help integrate noise control into the business process.

A national exposure database linked to noisy activities, hearing loss prevention outcomes, and hearing protection should be developed to provide a comprehensive reference.

Research into the development of low cost personal noise dosimeters or personal exposure monitors (with a retail cost of less than $100) can make information about hazard levels and total noise burden available to large groups of exposed people, in an occupational or social setting.

Consideration should be given to development of inexpensive hearing screening tools using the model of the musical greeting card. While not clinical in precision, this kind of gross self-screening could be a great asset in raising public awareness of noise as a hazard and in motivating the individual to maintain hearing health and function. Similar technology can be applied to personal hearing protector fitting.

Analysis should be conducted on the effect of the redistribution of responsibilities for hearing health. Based on current business trends, it is possible that hearing conservation will not be an exclusive management legal responsibility. The new paradigm will entail greater worker involvement, as the worker bears more responsibility for healthcare. Likewise, there will be greater supplier involvement as they bear more partnership responsibility for ensuring that their industrial consumers maintain safe and healthful workplaces.

Part of the supplier link involves consumer products as well. A labeling requirement like an MSDS for noise that would communicate to end-users the level of hazard, consequences of use, and appropriate self protective behaviors (e.g. using hearing protection or limiting time of use) can close the gap between the linked exposures in the workplace and elsewhere.

Personal Protective Equipment Agenda

Important aspects of the HPD utilization issue merit research. There is no current definition of HPD comfort and no real definition of effectiveness. HPD fitting, or an assessment of the protection provided by given device under given conditions to a given individual, should be addressed with improved methods and technologies for field fit testing and user training. Simple but reliable methods for self-assessment of fit should be developed, with annual training and verification of appropriateness of HPD selection part of the hearing loss prevention process.

Further study is needed on the effects of HPD on functionality in the workplace. Analysis of the effect of HPD use on warning signal detection; localization of noise sources; and speech and communication in the workplace are important. In addition, each of these research aspects should be considered for both the normal-hearing and for the hearing-impaired.

New technologies integrating speech communication systems and other technologies with HPD should be pursued, with special focus on tailoring systems for hearing impaired. Integration of multiple technologies including chemical exposure monitoring and other health surveillance should be considered to increase value and raise the credibility of the use of these devices.

Social Marketing Agenda

A fundamental failure of the existing system has been the reliance on regulation and on employers for responsibility to protect and maintain hearing health in society. Lack of a broad based social marketing effort to raise the awareness of the public on hearing health as a wellness issue speaks to under-valuation of hearing health in society.

The large-scale awareness campaign which will be required to raise awareness of society in general should be based on wellness models. This effort could be started by a consortium of professional associations to promote hearing health as wellness as a new paradigm. Worker groups, including organized labor; employers, both large and small; and the general population should be mobilized.

A focus on youth, using anti-smoking or other public health awareness models, could be a great preventive measure to improve the hearing health of those entering the workforce. Noise awareness media should be developed using tools like the tinnitus demonstration tape employed by the Carpenters Union and hearing loss demonstration media.