Speech Science Forum - Exploring the relationship between hearing acuity and operational performance in two different military environments
15 June 2016, 4:00 pm–5:00 pm
Event Information
Location
-
Room 118, Chandler House, 2 Wakefield Street
Speaker: Benjamin Sheffield, Walter Reed National Military Medical Center
Although
hearing is known to play an essential role in military operations, relatively
few studies have been conducted to directly measure the impact that a certain
level of hearing impairment will have on combat effectiveness. In this talk,
two studies will be highlighted that are attempting to define this
relationship. In one study, Soldiers from the 101st Airborne Division at Ft.
Campbell, KY, were equipped with wearable hearing loss simulators that allowed
parametric adjustment of their hearing profiles between normal hearing and
profound deafness. These soldiers then participated in a series of combat
exercises that required three or four fire teams with different levels of
hearing loss to progress through a series of waypoints in a wooded area as quickly
as possible without being eliminated. A sophisticated GPS-based tracking system
made it possible to track the progress of each team throughout the exercise,
including information on which players were eliminated by enemy gunfire and
which players were responsible for these kills. The results show that hearing
impairment has a substantially negative impact on the performance of
experienced soldiers in terms of survivability, lethality, and the ability to
progress through the waypoints. In another study, the performance of Navy
Watchstanders was tested in a simulated Combat Information Center (CIC)
exercise while wearing real-time intelligibility modification systems that
systematically controlled the speech intelligibility over shipboard
communication channels using speech-shaped masking noise. A novel adaptive
tracking procedure incorporating the modified rhyme test (MRT) was used to
determine the signal-to-noise ratios (SNRs) that resulted in 80%, 60%, and 40%
speech intelligibility for each individual. These SNRs were then tested along
with a quiet condition in randomized blocks of the operational scenario.
Participant performance was evaluated by subject matter experts in terms of the
ability to respond appropriately to critical mission events. Participant
comprehension of these events was also measured, and voice and eye-tracking
data were recorded to evaluate behavioral changes in difficult communication
settings. Results showed that as speech intelligibility decreased, participants
missed more communications, lost more situational awareness, communicated less,
and were less accurate when communicating. Participants also requested more
repeat backs, talked louder, talked slower and diverted more visual attention
away from relevant visual information sources. Taken together, these findings
demonstrate just how critical the sense of hearing is in military operations
and how important it is to preserve and protect hearing for the Warfighter. The
results of these studies will be used to develop improved accession and
retention standards for hearing impaired military personnel and to help define
better requirements for the acquisition of improved hearing protection and
communication systems for the military.
Time: Wednesday 15th June at 4pm
Venue: Room 118, Chandler House, 2 Wakefield Street
The Speech Science Forum (SSF) is a joint seminar series at UCL organised by the Department of Speech, Hearing and Phonetic Sciences (SHaPS) and the Institute of Cognitive Neuroscience (ICN).