4Berger, Elliott H., " Preferred methods for measuring hear- ing protector attenuation." Proceedings of Inter-Noise 2005, Noise Control Foundation, Poughkeepsie, NY, p.58.
5Michael, K. (1999). "Measurement of Insert-Type Hear- ing Protector Attenuation on the End-user: A Practical Al- ternative to the NRR," Spectrum 16(4), 13-17.
6Edwards, R. G., Broderson, A. B., Green, W. W., and Lempert, B.L. (1982). "A Second Field Investigation of Noise Reduction Afforded by Insert-Type Hearing Pro- tectors," NIOSH, U.S. Dept. of HHS, Rept. No. 210- 81-3001, Cincinnati, OH.
7E. H. Berger, J. Voix, and R. W. Kieper, "Methods of de- veloping and validating a field-MIRE approach for measur- ing heating protector attenuation," Spectrum--National Heating Conservation Association _NHCA_Publications 24, Supplement 1, p. 22 (2007).
8ISO 11904-2:2002, Acoustics, Determination of sound im- mission from sound sources placed close to the ear, part 2: technique using a manikin.
9ISO 4869-3:2007, Acoustics, Hearing protectors, part 3: measurement of insertion loss of ear-muff type protectors using an acoustic test fixture.
10American National Standards Institute (1957). Method for the Measurement of the Real-Ear Attenuation of Ear Pro- tectors at Threshold. Standard Z24.22-1957 (R 1971), New York, NY.
