Back to Top Skip to main content Skip to sub-navigation

Researchers find key senses impact readiness, survival

Military personnel in driver and casualty evacuation training A Soldier assigned to Alpha Company, 24th Military Intelligence Battalion, 66th Military Intelligence Brigade, provides security as part of Anglerfish Day driver and casualty evacuation training at Dagger Complex, Germany in April 2021 (Photo by: Army Staff Sgt. Thomas Mort).

Recommended Content:

Vision and Hearing Loss Prevention | Vision and Hearing Loss Prevention | Hearing Loss

Proper hearing in an operational environment is vital to mission success. The loss of this key sense can not only impact unit readiness, but also result in negative consequences for the individual.

"Sound localization is a critical component of situational awareness, or to put it in layman's terms, knowing what is going on around you," said Robert Williams, an engineer with the Defense Health Agency's Hearing Center of Excellence, at Aberdeen Proving Grounds, Maryland.

Recently, military researchers conducted a series of studies to learn more about how hearing can impact situational awareness. They found that service members who could not locate the source of a sound not only had diminished performance, but experienced a higher number of fatalities in the test scenarios.

Service members who took part in the research used programmable headsets during paintball and field exercises to simulate varying levels of hearing loss and how it can affect sound localization. These studies were conducted by Walter Reed National Military Medical Center in Bethesda, Maryland; and Naval Surface Warfare Center Dahlgren Division in Virginia.

"Sounds can be used to draw our attention to certain things, which can then be verified by our eyes," said Williams. "Your eyes can see in front of you, but they don't work as well in the dark, or when obscured by smoke, fog, dust, or other obstacles. But you can hear in the dark, or through fog, and the ability to hear can alert us to hazards or other things that we need to be aware of."

According to Dr. Felix Barker, DHA Vision Center of Excellence, director of rehabilitation and reintegration, vision and hearing are our two most important remote sensing capabilities, and essential to the warfighter.

"When they don't work optimally in a threat situation, this can make the service member effectively "blind or deaf" to the threat," said Barker. "Both senses are also highly interactive. Hearing produces initial awareness of the threat, even when it is coming from behind you. Hearing then helps define the target location so that the threat can be acquired visually, engaged and destroyed."

For those with hearing loss, Williams explained that the ability to localize sounds may also be diminished. "This could occur because they may not be able to hear a sound at all, or because our brains use certain frequencies of sound to determine their location. If we lose the ability to hear these frequencies, we may still be able to hear a sound, but not be able to localize it."

Another factor influencing sound localization is certain types of hearing protection devices, which can cause localization errors and affect situational awareness.

"Unfortunately, hearing protection often diminishes the ability to localize," explained Dr. Theresa Schulz, HCE prevention branch chief. "We lose the information provided by our pinna-- the part of the ear that holds up our glasses. Some hearing protector manufacturers make efforts to minimize the disruption to localization, but none are as good as the open ear. While localization is important, so is protecting the more basic ability to detect, identify and recognize sounds."

"There are a number of studies conducted by the Department of Defense and academia to create localization assessment methods for hearing protection, which have enhanced the DOD's knowledge of how localization affects operational performance,' added Schulz.

Certain military career fields are particularly dependent on a keen ability to localize sound, not only for mission effectiveness, but for survival, according to Schulz. "Ground troops and force protection personnel must be able to localize sounds when on a perimeter watch, for instance, to hear someone approach," said Schulz. "The ability to hear a sound and determine the direction can also help service members find targets. They must be able to detect and localize sounds as well as understand verbal commands whether face-to-face or over a radio."

Studies conducted by the National Institutes of Health show the brain uses many sensory cues to determine the location of a sound. When hearing and vision work together, a person can often determine where sound is coming from faster.

"Both threats and opportunities can be identified using our ears and eyes," explained Schulz. "Hearing a sound is often the first clue to where a sound is coming from, and then we look in a limited area to identify more specifically the source of the sound. Our brains use the difference in loudness between our two ears and the difference in timing of the sound's arrival between our two ears to determine where the sound came from."

By the same token, vision and hearing do not work independently, explained Dr. Mike Pattison, VCE's program manager of readiness and operations optometry. "The two senses work together to create our perception of what we experience in the real world. For most sighted people, in situations where the visual input is unclear such as at dusk or in a dark building, hearing takes on a more prominent role," said Pattison.

Schulz noted that while sound localization is possible with some hearing or vision loss, if both hearing and vision senses are impaired, this ability can become greatly jeopardized.

"Vision and hearing can augment and compensate each other, but if there is a dual sensory loss, much of this critical redundancy is lost. It's so important to always protect your vision and hearing senses by wearing the right protective equipment for your mission, and getting regular hearing and vision checkups to stay mission ready, and to survive and thrive."

You also may be interested in...

HCE celebrates 10 years focused on hearing health

Article
7/14/2020
Woman exhibiting correct earplug insertion

Look back on 10 years of service, and what’s been done so far in support of the mission.

Recommended Content:

Hearing Loss

Center develops tool to help service members select optimal hearing protection

Article
5/21/2020
Marine holding and aiming a rifle

Hearing loss can have severe consequences for our health and future well-being.

Recommended Content:

Hearing Loss

Portable system demonstrates capability to save hearing downrange

Article
5/13/2020
Image of three soldiers looking at an iPad

Army audiologist demonstrates new hearing test system while deployed to Iraq.

Recommended Content:

Hearing Loss

Innovative military hearing health programs showcased at national conference

Article
3/5/2020
Lt. Col. John Merkley, Army Public Health Center, tests out a boothless audiometry headset system, one of four systems demonstrated by manufacturers during a workshop hosted by the DoD Hearing Center of Excellence at this year's National Hearing Conservation Association Conference. (HCE photo)

Hearing standards for new Air Force recruits saved the military service millions of dollars

Recommended Content:

Hearing Loss

World Hearing Day shines light on global hearing loss

Article
3/2/2020
Air Force Senior Airman Joseph Finigan, 100th Aircraft Maintenance Squadron aircraft hydraulics systems journeyman, puts on a second layer of hearing protection over his dual in-ear headset at RAF Mildenhall, England. The headset enables communication by transmitting sound waves through the bones in the user's ear. (U.S. Air Force photo by Airman 1st Class Joseph Barron)

Hearing loss declines among service members, DoD civilians

Recommended Content:

Hearing Loss

DHA PI 6025.12: Retiree At Cost Hearing Aid Program Retiree Hearing Aid Purchase Program (RACHAP)

Policy

This Defense Health Agency-Procedural Instruction (DHA-PI): a. Based on the authority of References (a) and (b), and in accordance with the guidance of References (c) through (r), establishes the Defense Health Agency’s (DHA) procedures to establish common and uniform guidelines, standards, and procedures for all DoD MTFs providing hearing health services to beneficiaries through RACHAP. This program has been operating at self-selected MTFs without established DoD guidance. b. Enables MTFs with capacity and capability to provide hearing aid evaluation, selection, fitting, and follow-up appointments utilizing an at cost Federal Government contract price through RACHAP to RACHAP-eligible beneficiaries (“RACHAP-eligible beneficiaries” defined in the Glossary). c. Incorporates, cancels, and replaces Reference (s).

  • Identification #: 6025.12
  • Date: 7/12/2019
  • Type: DHA Procedural Instruction
  • Topics: Hearing Loss

Defense Occupational and Environmental Health Readiness System – Hearing Conservation (DOEHRS-HC)

Fact Sheet
6/17/2019

The Defense Occupational and Environmental Health Readiness System – Hearing Conservation (DOEHRS-HC) is an information system designed to support personal auditory readiness and help prevent hearing loss through early detection.

Recommended Content:

Technology | Hearing Loss | Solution Delivery Division

Exiting an A-10C Thunderbolt

Photo
9/30/2016
U.S. Air Force Senior Airman Judith Bulkley, an electrical and environmental systems specialist deployed from the 23rd Aircraft Maintenance Squadron, Moody Air Force Base, Ga., exits an A-10C Thunderbolt II after performing an external power operations check on the aircraft at Kandahar Airfield, Afghanistan. Because service members in particular are often exposed to high noise levels, hearing protection is crucial, especially with a TBI. (U.S. Air Force photo by Tech. Sgt. Stephen Schester)

U.S. Air Force Senior Airman Judith Bulkley, an electrical and environmental systems specialist deployed from the 23rd Aircraft Maintenance Squadron, Moody Air Force Base, Ga., exits an A-10C Thunderbolt II after performing an external power operations check on the aircraft at Kandahar Airfield, Afghanistan. Because service members in particular are often exposed to high noise levels, hearing protection is crucial, especially with a TBI. (U.S. Air Force photo by Tech. Sgt. Stephen Schester)

Recommended Content:

Hearing Loss | Traumatic Brain Injury

Lt. Col. James Morrison getting adjustments to cochlear implant

Photo
9/22/2016
Dr. Elizabeth Searing (right) makes initial adjustments via a computer to Lt. Col. James Morrison's cochlear implant. Dr. April Luxner, an audiologist with Cochlear Corporation, was on hand to witness Morrison's reactions to hearing with his right ear after 12 years of deafness. (U.S. Army photo by Jeff Troth)

Dr. Elizabeth Searing (right) makes initial adjustments via a computer to Lt. Col. James Morrison's cochlear implant. Dr. April Luxner, an audiologist with Cochlear Corporation, was on hand to witness Morrison's reactions to hearing with his right ear after 12 years of deafness. (U.S. Army photo by Jeff Troth)

Recommended Content:

Hearing Loss

Addendum to Guidance on the Establishment of Department of Defense Standardization for Ordering and Procurement of Hearing Devices Prostheses 13-006

Policy

This memorandum clarifies procedures relating to Health Affairs' "Guidance on the Establishment of Department of Defense Standardization for Ordering and Procurement of Hearing Devices/Prosthesis," dated August 15, 2013, which remains in effect.

  • Identification #: 13-006
  • Date: 10/20/2014
  • Type: Memorandums
  • Topics: Hearing Loss
<< < 1 2 3 > >> 
Showing results 31 - 40 Page 3 of 3

DHA Address: 7700 Arlington Boulevard | Suite 5101 | Falls Church, VA | 22042-5101

Some documents are presented in Portable Document Format (PDF). A PDF reader is required for viewing. Download a PDF Reader or learn more about PDFs.