The question of whether radio earmuffs provide protection or add damaging noise is addressed in a new Sound Source article recently released by Bacou-Dalloz, parent company of the Howard Leight and Bilsom hearing protection brands.
Authored by Brad Witt, MA, CCC-A, who is Audiology and Regulatory Affairs Manager for the company and available on their website, the Sound Source article discusses the difference between headset radios and hearing protector earmuffs equipped with AM/FM radios and explains how to calculate effective noise exposure while wearing them.
"When headset radios first appeared in stores several decades ago, they were not marketed as hearing protectors," says Witt, adding that this was, "a good thing, since they offered little attenuation of noise. At some frequencies, the headsets were even found to amplify background noise (with the radio turned off) due to resonance in the earcup."
To be a hearing protector, says Witt, an earmuff must be designed to be a hearing protector from the start.
The volume settings of typical portable stereo headsets have been measured as high as 96 dBA at 100% volume, "a hazardous noise level if listened to continuously for several hours.
Ideally, a radio headset should allow the enjoyment of music at safe levels, but also reduce the background disturbance in a noisy environment."
Today's new hearing protectors do just those, he reports.
Built-in radios contain circuitry that limits their maximum radio volume. When the radio is turned on, for example, the sound output is electronically limited to 82 dB. But the questions that concern many are:
When using these earmuffs in an industrial setting, would not the radio simply add more noise to damage hearing? And what are the noise levels under the earcup when the radio is turned on?
"When two noise sources are added together, the decibels are added logarithmically, not arithmetically," Witt explains. "This means that the sum of two identical sound sources (90 dB + 90 dB) would equal 93 dB."
The Sound Source article goes on to provide a chart, illustrating the effective noise exposure levels for a typical radio earmuff worn in 90 and 100 dB of noise.
"Since the radio output is limited to a safe 82 dB maximum, the radio adds little noise to effective exposures in high noise levels," Witt concludes.
"In a high-noise job that is also repetitive or monotonous, a radio earmuff can add significantly to worker satisfaction and enjoyment, without sacrificing hearing protection."
Since its beginnings as a one-man operation more than 30 years ago, Howard Leight Industries has grown into one of the large manufacturers of in-ear hearing protection in the industrial market and is widely recognised as an innovator in protection and fit.
Since 2001 Howard Leight has been a part of the Bacou-Dalloz Hearing Safety Group.
Bilsom was founded in Sweden in 1968 and leads the industry in developing innovative sound management technologies that are used in some of the most challenging environments in the world.
Combining the innovation and expertise of Howard Leight Earplugs and Bilsom Earmuffs, the Bacou-Dalloz Hearing Safety Group is a world leader in hearing safety.
Bacou-Dalloz is the world leader in the design, manufacture and sale of personal protective equipment, offering a comprehensive range of safety products designed to protect people from hazards in the workplace.
The Group specialises in head protection equipment (eye and face, respiratory and hearing protection), body protection equipment (clothing, gloves and footwear) and fall protection equipment.
With a worldwide presence and over 6,000 people, Bacou-Dalloz endeavors to contribute to ongoing improvements in workplace health and safety by providing innovative, comfort-engineered products that workers want to wear.
The Group’s products are sold through a worldwide network of distributor partners for use in all sectors of activity (construction, manufacturing, telecommunications, homeland security, petrochemicals, medical, public services, etc.).
Bacou-Dalloz is listed on the Premier Marché of the Euronext stock exchange in Paris, and is part of the SBF 120 index.