The Impact of Reduced Speech Intelligibility on Reaction Time in a Naval Combat Environment

Abstract

Despite attempts to limit noise exposure, noise-induced hearing loss remains prevalent in the military. Both hearing loss and the noise itself can lead to communication issues which could negatively impact operational performance. This study builds upon a series of experiments examining the relationship between reduced speech intelligibility and performance in a naval command and control environment by equipping Navy watch standers with hearing loss simulators that control speech intelligibility in real time as they were engaged in a simulated operational scenario. This effort focused on the effects that a Sailor with impaired hearing might have on unimpaired shipmates and how the mission might specifically be impacted. Results showed that as speech intelligibility decreased for the impaired watch stander perceived workload increased in an unimpaired shipmate and the latency of the crew to respond to incoming missile threats and a direct order to kill an enemy ship increased significantly.

Developing an Evidence-Based Military Auditory Fitness-for-Duty Standard Based on the 80-Word Modified Rhyme Test

“…In a second series of studies, Keller et al (2017) and Sheffield et al (2017) examined the effect of impaired communication on trained Aegis Missile Cruiser personnel playing the roles of CIC Watch Officer and Tactical Air Official in a simulated naval Command Information Center (CIC). Again, the level of communication accuracy was controlled by having the two participants read lists of MRT words over the intercom and adjusting the noise level until the desired level of intelligibility was obtained.…”

Toward Predicting Human Performance Outcomes From Wearable Technologies: A Computational Modeling Approach

“…First, simple reaction time resides at a most basic level of cognitive processes, whereas choice and serial reaction time tasks can elicit higher-order processing (i.e., executive function) as evidenced by activation of inhibitory processes and anterior cingulate and prefrontal cortical circuits ( Naito et al, 2000 ; Mulert et al, 2003 ; Burle et al, 2004 ). Second, maintaining vigilant attention and quickly reacting to emerging events is critical for sustained performance in a number of high-stakes tasks including those characteristic of military and first-responder operations ( Truszczynski et al, 2014 ; Vrijkotte et al, 2016 ; Sheffield et al, 2017 ; Dominski et al, 2018 ; Brunyé et al, 2020 ). Finally, reaction time is well-characterized and widely available for efficient download and integration into our modeling approach, and has proven sensitive to variations in acute stress ( Lieberman et al, 2002 ; Olver et al, 2015 ), sleep loss ( Forest and Godbout, 2000 ; Bartel et al, 2004 ; Deslandes et al, 2006 ), and physical exertion ( Chang et al, 2012 ).…”

Performance in Noise: The Relationship Between Workload And Situation Awareness in Navy Tactical Teams

“…Not only is hearing loss a concern, but Garinther and Peters (1990) found tactical performance decrements caused by reduced speech intelligibility (SI). Recent research has echoed the finding that impaired hearing leads to degraded performance and behaviors that could compromise a mission (Sheffield et al, 2016;2017;Keller et al, 2016;Casto et al, 2012). Those findings highlight the importance of understanding how impaired hearing impacts behaviors related to operational performance, by interfering with mental workload, situation awareness (SA), and team communication.…”

“…In high mental workload conditions, performance suffers when compared to performance under low mental workload (Wickens, 2004). A study by Sheffield et al (2017) showed how reduced SI increased stress, perceived task workload, and the number of failures for Navy watch standers. The loss of SA can have serious consequences because it guides decision making and actions (Durso & Gronlund, 1999).…”