History & Development of Hearing Protection Devices

Whether you play in a rock band, cook in a school cafeteria or live in a bustling urban neighborhood, you face the risk of noise-induced hearing loss. Although everyone can prevent hearing loss by wearing proper hearing protection, people did not always have as many options. Hearing protection devices took years of development.

History

• The U.S. Patent Office approved hearing protection devices as early as the 1800s; however, according to the "Journal of the Acoustical Society of America," most Americans did not start using hearing protection until the 1920s, when urban dwellers wore them to protect their hearing from ambient city noise.

  When World War II soldiers returned home, many suffered serious hearing loss, prompting the military to research protective devices. In 1948, the U.S. Air Force began the first hearing conservation program, and the aviation and metals industries followed suit in the late 1940s and 1950s. Hearing protection continued to gain popularity, and in 1983, the Occupational Safety and Health Administration adopted the Hearing Conservation Amendment to its existing noise regulations.

Major Developments

• Prior to World War II, Vern Knudsen was working on an "ear defender" device, which consisted of a rubber tube inserted into the ear canal and an outer metal plug; this reduced loudness by one-tenth and helped soldiers during World War II, according to a 1939 "Popular Mechanics" article. During World War II, Harvard researchers developed headphone cushions like the ones on acoustical earmuffs that seal out sound.

  In 1962 Americans saw the introduction of silicon earplugs, which you can roll in your fingers to the appropriate size to cover--but not insert in--your ear canal. The inventors, Ray and Cecelia Benner, intended them primarily for swimmer's ear. However, silicone earplugs do offer protection against noise. A decade later, Ross Gardner patented the foam earplug, and it quickly grew in popularity.

Function

• Hearing protection devices block noise to protect the sensitive hair cells and nerves from damage. Hair cells inside your ears convert sound waves to electrical signals, and once these hair cells are damaged, they can never grow back. When noises reach 85 decibels or greater, you risk permanent hearing loss, but you can prevent it by using hearing protection devices, according to the National Institute of Deafness and Other Communication Disorders (NIDCD).

Types

• Hearing protection comes in many different forms. Foam earplugs fit right into the ear canal and physically block sound. Some come pre-molded and ready to insert, while others require you to roll them in your fingers to make them fit your ear canal. If you shoot at a pistol range, you have probably seen earmuff hearing protection. These look like headphones, but instead of transmitting sound, they block it. Some hard hats come with earmuffs attached.

Significance

• Noise-induced hearing loss makes the world sound muffled, garbled or even silent. Hearing loss from on-the-job noise exposure accounts for the largest number of occupational illnesses, according to the NIOSH website. Noise-induced hearing loss happens outside work, too. As of 2010, approximately 26 million Americans between the ages of 20 and 69 have "high frequency hearing loss due to exposure to loud sounds or noise at work or in leisure activities, according to the NIDCD.

Considerations

• Although hearing protection devices offer reliable protection against hearing loss, NIOSH warns that they only work if you develop conscious habits. You need to make them part of your routine.