Why Aegisound Products are Needed Now

The post-war and modern eras have brought the world incredible strides in military innovation. From weapon systems to vehicles, military personnel find themselves in control of increasingly advanced and powerful technologies not only in combat but away from the field as well. As these technologies have grown more impressive, so too have the risks and health effects. Take for example an F-14 aircraft performing a catapult launch from a carrier. At afterburner setting, an F-14 produces 149 dB of noise. At such levels (approximately 29 dB above the human pain threshold) ear damage can occur almost immediately without protection. While such harsh noise environments have become common in many military settings, some of the greatest risks are found on board aircraft carriers.

In the 70’s the issue of hearing preservation aboard aircraft carriers became a relevant question. Even then, as studies showed, available technology posed a threat to military personnel’s hearing health. Now with more powerful engines aboard many of the aircraft coming and going from U.S. carriers, the threat has risen. In response to this, a study of the acoustical noise fields on carriers was conducted in late 2000. The results of the study stated that “for a projected mission of 60 launches and 60 recoveries within a 24-hour period, Total Daily (Noise) Exposure (TDE) limits were exceeded at many flight deck personnel locations.” (McKinley, Barrow) Not only is this fact a significant finding, but these results assume all personnel at 30dB attenuation given correctly applied hearing protection devices, as well as personnel having no exposure to noise levels above 80dB throughout the rest of the day. Both of these facts are questionable aboard most aircraft carriers. Very rarely is the maximum attenuation of 30 dB achieved given inconsistencies with foam plug insertion, as well as incorrectly sized cranial devices (Bjorn, see chart below). It is also true that throughout a flight deck personnel’s day, there will be many instances where ambient noise is above 80 dB. (McKinley, Barrow) These studies have made it clear that improved HPDs are greatly needed to avoid costly and handicapping hearing loss.

The results of such hearing loss are many fold. In 2005, the Veterans Administration spent over $786 million on hearing loss disability compensation alone (VA). This represents an increase of over 100% in VA hearing loss payouts in only 5 years. Long term affects are often the easiest to observe, but what these numbers don’t take into account are the numerous disadvantages within the operational consequences of hearing loss such as re-training costs for replacement personnel, and the ultimate cost of mission effectiveness. In fact, it has been shown that as speech intelligibility decreases within operational mission environments there is a direct correlation to a reduction in the probability of that mission’s success (Dancer, Buck). Such glaring issues as these have contributed to many efforts at reducing the effects of harsh noise environments.

Hearing protection devices were first developed for the military in the 1950’s. Unfortunately, the culture of innovation that has affected many other areas of military technology has not been so prevalent within the arena of hearing protection. Steps have been taken to reduce the affects of harsh noise environments but they have largely been ineffective. Double Hearing Protection devices are required by legislation within exposure to harsh noise environments, but due to a lack of standardization and ease in the devices used, improper usage or no use at all often occurs (Bjorn). It is with all this in mind that Aegisound strives to manufacture the best hearing protection devices available on the market today.

References

A. Dancer and K. Buck – “Acoustics and Protection of the Soldier” (APC)
Geoffrey B. Shaw and Robert P. Trost – “Statistical Analysis of Hearing Loss Among Navy personnel
Valerie S. Bjorn, Christopher B. Albery, Richard L. McKinley – “U.S. Navy Flight Deck Hearing Protection Use Trends: Survey Results”
Richard L. McKinley, Charles Barrow, Capt. Brian Davis, James D’Andrade, and Frank Mobley – “Acoustical Noise Fields Generated on the Flight-Deck during Operations of F/A-18C, F-14B, EA-6B, and S-3B Aircraft”
Doug Ohlin – “Cost Effectiveness of Hearing Conservation Programs”