Ear Plugs and their Various Uses
Ear plugs, like many of the devices used today, are not a new concept, but another example of an idea that may have originated in ancient Greece. Certainly the earliest reference to them is to be found in Homer’s epic tale – The Odyssey. Believed to have been written in about 1178 BC, it contains a passage in which the ship’s crew is advised to fashion them from beeswax, in order to counter the seductive songs of the sirens that were reputed to lure sailors to their death on an enchanted island.
However, it took almost another 21 centuries before the first company to manufacture ear plugs commercially, also from wax, opened in Germany in 1907. A little under 60 years later, a mouldable silicone version began to replace those made from wax or, in some products, clay. Their main purpose then, as now, was either to reduce the effect of loud noise, often to assist those who found it difficult to sleep, or to be worn by swimmers in order to prevent the entry of water into the external auditory canal – a common source of infection in certain rivers and pools that had not been treated with chlorine.
Far more effective in reducing noise, the material commonly used today to manufacture ear plugs is a resin with an exceptional ability to absorb energy. Appropriately named E-A-R (Energy Absorption Resin), it was first produced in the US in 1967 and refined in 1972 to create the high-end, commercial memory foam products that have since become so popular. In the workplace, however, products made from either of the high-density synthetics, polyurethane (PU) or polyvinyl chloride (PVC), provide a very effective sound barrier while costing a good deal less than the equivalent memory foam products.
While their ability to protect swimmers from infection and to provide partial relief for insomniacs remain among their common uses, the role of ear plugs in the prevention of noise induced hearing loss (NIHL) is undoubtedly their most important application. More education is needed regarding the potential for irreversible damage to hearing posed by repeated, prolonged exposure to loud noise. While the motor of a domestic refrigerator generates around 45 decibels and normal conversation around 60 decibels, exposure to sound at levels of 85db or more, if prolonged, will cause hearing loss.
It is worth noting that a lawnmower, for example, can produce around 100 decibels and will need no more than 15 minutes to cause hearing loss. Normally, a few days of comparative silence should result in recovery, but simply wearing ear plugs could have prevented even this temporary discomfort. However, for those whose job may require them to use noisy machinery for up to 8 hours a day and 5 days or more a week – these simple yet effective devices, or some equivalent protection, are an absolute necessity.
The safety of employees’ hearing is now largely protected by legislation covering health and safety in the workplace. In far greater danger are our children who regularly subject themselves to music at levels of 120db and more for hours on end, and who are now showing signs of permanent impairment from as early as 8 years of age. For them, ear plugs are not an option, but a vital necessity.