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NIOSH - National Institute for Occupational Safety and Health
NIOSH Hearing Loss Research Program Review NIOSH Publications on Noise and Hearing The National Academies - Advisors to the Nation on Science, Engineering, and Medicine

What has the program achieved?

In this section ....

Research Goal 1

Research Goal 2

Research Goal 3

Research Goal 4

HLR Databases

Acronym Finder

Outputs and Transfer - Research Goal 2.2:
Develop hearing protection laboratory and fit-testing methods

The HPDLab software and fit-testing research have been the topic of over twenty presentations at national and international conferences. The results of the comparison of field testing methods were published in the American Industrial Hygiene Association Journal. The HLR program has worked closely with hearing protector industry manufacturers who review NIOSH research findings and proposals.

 Intermediate Outcomes

HPDLab was developed as a tool for the HLR program to research testing methods and as a product for commercial testing laboratories with a lowered entry cost. Both PRL and HLI laboratory have achieved NVLAP accreditation for ANSI S12.6-1997. HLI performs in-house testing of their products and has recently completed their portion of the NIOSH-sponsored interlaboratory study with the HPDLab software. The U.S. Army Aeromedical Research Laboratory and Gentex Corporation have commenced the installation of HPDLab for use in the development of crew communication systems.


The NIOSH Pittsburgh Research Laboratory HPDLab testing system uses commercially available signal generation equipment, audio amplifiers and speakers controlled through software developed by the HLR program

HPDLab Testing System in Pittsburgh Research Labs















>> View What's Ahead for this Research Subgoal


Journal Articles

Murphy WJ, Franks JR, Berger EH, Behar A, Casali JG, Dixon-Ernst C, Krieg EF, Mozo BT, Royster JD, Royster LH, Simon SD, Stephenson C [2004]. Development of a new standard laboratory protocol for estimation of the field attenuation of hearing protection devices:  sample size necessary to provide acceptable reproducibility. J Acoust Soc Am 115(1): 311-323.

Franks JR, Murphy WJ, Harris D, Johnson JL, Shaw PB [2003]. Alternative field methods for measuring hearing protector performance. Am Ind Hyg Assoc J 64(4):501-509.

Berger EH, Franks JR, Behar A, Casali JG, Dixon-Ernst C, Kieper RW, Merry CJ, Mozo BT, Nixon CW, Ohlin D, Royster JD, Royster LH [1998]. Development of a new standard and laboratory protocol for estimating the field attenuation of hearing protection devices, Part III:  the validity of using subject-fit data. J Acoust Soc Am 103: 665-672.

Royster JD, Berger EH, Merry CJ, Nixon CW, Franks JR, Behar A, Casali JG, Dixon-Ernst C, Kieper RW, Mozo BT, Ohlin D, Royster LH [1996]. Development of a new standard protocol for estimating the field effectiveness of hearing protector divides, Part I:  research of working group II, accredited standards, committee S12, noise. JAcoust Soc Am 99: 1506-1526.


Murphy WJ, Byrne D, Witt B, Duran J [2005]. Psychophysical uncertainty estimates for Real Ear attenuation at threshold measurements in naïve subjects. NoiseCon 2005, Minneapolis, MN, Oct. 17.

Murphy WJ, Franks JR, Davis RR. [2005]. Field measurements of Hearing Protection Device Performance. InterNoise 2005 / Rio de Janerio, Brazil, August 6.

Franks JR, Murphy WJ, Suter A [2003]. United States Environmental Protection Agency, Workshop on Hearing Protector Devices. Papers and Proceedings, Washington DC.

Franks JR [2001]. State of the Art: New testing methods and passive hearing protectors. In: Proceedings of Noise Induced Hearing Loss Basic mech., prev. & cont.

Franks J, Berger E [1998]. Personal protection:  Hearing protection. In: Stellman J, ed. Encyclopedia of Occup. Health and Safety (4th ed., p. 31.11-31.15). Geneva Switzerland: Int. Labor Office.

Berger EH, Franks JR, Lindgren F [1996]. International review of field studies of hearing protector attenuation. In: Axelsson A, Borchgrevink HM and Hamernik RP, eds. Scientific Basis of Noise-Induced Hearing Loss. New York: Thieme Medical Pub Inc., pp. 361-377.



Murphy WJ, Franks JR. [2002]. Software development for NIOSH hearing protector testing, J. Acoust. Soc. Am., Vol. 112 No. 5 Pt. 2, 2295.

Murphy WJ, Franks JR. [2000]. A statistical classifier for hearing protector REAT data. J. Acoust. Soc. Am. Vol. 108, No. 5 Pt. 2, 2621.

Franks JR, Harris DA, Johnson JL, Murphy WJ. [1999]. Alternative field methods of measuring hearing protector performance. Abstracts of the Midwinter Meeting of the Association for Research in Otolaryngology, 22.

Murphy WJ. [2000]. Evaluation of a Real-World Hearing Protector Fit-Test System. National Hearing Conservation Association, Denver, CO February 18.

Murphy WJ, Franks JR. [1999]. Evaluation of a FitCheck hearing protector test system. J Acoust Soc Am Vol. 106 No. 4, Pt. 2, 2263.

Murphy WJ, Franks JR, Hall SJ, Krieg EF. [1997]. Differences between binaural sound-field thresholds and monaural audiometric thresholds, J. Acoust. Soc. Am., 101, No 5, Pt. 2, 3126.

Franks JR, Murphy WJ, Simon SD. [1996]. Repeatability and reproducibility in hearing protector testing. J. Acoust. Soc. Am., 99, 2464.



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