When it comes to headphones, you can choose from a diversity of types and styles. Headphones can also be used in a number of different applications. A common place to find them is in the work environment, where they generally are used to block out, filter or eliminate noise. Federal regulations stipulate the kind of circumstances where they are mandatory in the workplace.
The headphones most likely to be used by everyday consumers are those that deliver sound to the ears, specifically music or other audio recordings. Headsets, combining headphone and microphone, are typically for two-way telecommunication by telephone or dispatch operators and numerous others. Noise-cancellation headphones block out various sounds, particularly in the workplace.
Because headphones can deliver sound at extreme volumes, they present a potential hazard to the listeners. Although this is especially true with music, it can also apply to work-related listening that requires frequent use of headphones. On the other hand, many work environments expose workers to such excessive noise that employers provide headphones as hearing protectors. The Occupational Safety Health Administration (OSHA) has regulations that apply to wearing headphones, particularly due to extreme workplace noise.
Strict mandates are based on OSHA calculations of the number of decibels (measurements of sound) an employee should be exposed to. Applicable laws are found in the Code of Federal Regulations, Title 29, Chapter XVII, Part 1910, Subpart G, 1910.95: sections (g), (h). These related regulations specify how much and how long is an acceptable workplace noise tolerance level. OSHA provides the formula it uses to arrive at the standard of 85 decibels in an eight-hour time-weighted average (TWA). According to OSHA, "For an eight-hour workshift with the noise level constant over the entire shift, the TWA is equal to the measured sound level."
OSHA requires employers not just to develop but to "implement a monitoring program [to] measure employee noise exposure." Exposure should not exceed 85 decibels within the determined allowable work period. Employers must notify employees if they have been exposed to work-noise levels exceeding the standards. Other requirements include establishing a way to regulate compliant audio testing, and providing or, when necessary, replacing acceptable hearing protectors, such as headphones.
Regulations governing acceptable workplace hearing protectors include the circumaural models that are conventional over-the-head, speaker-like headphones. They cup the entire ear and form a seal that isolates sound. A similar version is the supra-aural type, which sits on the ear but doesn't form a seal. Both comply with OSHA regulations. Another type that meets the standards are canalphones, a newer kind that fits into the ear canal. In harmony with the National Institute for Occupational Safety and Health, headphones are one way of "...attempting to conserve hearing by focusing on preventing occupational noise-induced hearing loss."