A member of the public asked OSHA whether noise-canceling headphones can substitute for intra-aural earplugs, asserting that 'earplugs are not really recommended (people are not supposed to put things in their ears).' OSHA's response covers both the earplug misconception and how noise-canceling technology fits into hearing conservation.
OSHA first laid out the regulatory framework: since 1971 employers must protect workers from hazardous noise, with a permissible exposure limit of 90 decibels, A-weighted (dBA) as an 8-hour time-weighted average (TWA), and the 1980 Hearing Conservation Amendment set an action level of 85 dBA TWA that triggers a comprehensive hearing conservation program (29 CFR 1910.95). Engineering controls are 'the most effective and feasible for most noise sources,' but hearing protection devices are permitted when they effectively attenuate occupational noise exposure. On the earplug concern, OSHA explained that earplugs between 1/2 and 3/4 of an inch long would not contact the eardrum even if fully inserted, and many designs are pre-molded or have stems that prevent direct ear canal contact.
On the technology itself, OSHA distinguished passive noise canceling (PNC) — heavy-duty soundproofing designs traditionally used as effective components of workplace hearing conservation — from active noise canceling (ANC) headphones marketed to consumers for entertainment, which are generally ineffective for occupational noise protection because they fail against 'sudden, explosive sounds.' Hybrid headphones combining passive and active features, with Noise Reduction Ratings (NRR) between 20-30 dBA, 'may be acceptable for use in some workplace situations.' Employers must select devices with sufficient sound attenuation to reduce worker exposure to 85 dBA TWA, using the EPA-measured NRR (29 CFR 1910.95 App B).
OSHA's bottom line: no regulation explicitly prohibits headphones on worksites, but employers must provide appropriate hearing protection devices based on a noise exposure evaluation, and consumer noise-canceling headphones are 'not recommended' as substitutes for laboratory-tested devices. The letter also warned that 'OSHA approved' marketing claims are misleading, as OSHA 'does not register, certify, approve, or otherwise endorse' commercial products.