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ERIC Number: EJ1083309
Record Type: Journal
Publication Date: 2006-Dec
Pages: 2
Abstractor: As Provided
ISSN: ISSN-0031-921X
Earplugs and the NRR
McCall, Richard P.
Physics Teacher, v44 n9 p580-581 2006
Earplugs are sold in most pharmacies. Because I teach at a college of pharmacy, I want my students to understand a particular feature of earplugs called the Noise Reduction Rating, or NRR. The NRR is a rating of the effectiveness of earplugs at decreasing the amount of sound (or noise) entering the ear. Typical values range from 12 dB to 33 dB; the ones I demonstrate in my class have a value of 29 dB.
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A