Evaluation of Auditory Characteristics of Communications and Hearing Protection Systems

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA514651&Location=U2&doc=GetTRDoc.pdf

Evaluation of Auditory Characteristics of Communications and Hearing Protection
Systems (C&HPSs) Part II – Speech Intelligibility


Paula Henry and Rachel Weatherless


Devices that provide hearing protection, situational awareness, and radio communications are often referred to as Communications and Hearing Protection Systems (C&HPSs). Soldiers use these systems while deployed to navigate within
their environment, communicate with their team members, and protect their hearing. Each of the three features of select C&HPSs (hearing protection, speech communication, and situational awareness) was evaluated by the U.S. Army Research
Laboratory in order to obtain data that is independent from that provided by the manufacturer. This report is the second in an series of three and focuses on the speech intelligibility performance obtained from two commercially available C&HPSs: Nacre QuietPro and Silynx QuietOps selected from three C&HPSs evaluated for attenuation characteristics in the first report. Results of the speech intelligibility testing indicated that the Silynx QuietOps provides a significantly higher degree of speech intelligibility, but this difference is probably not significant for field applications. The differences noted in speech intelligibility
are likely due to a combination of differences in the frequency responses measured from the two systems and differences in the frequency responses of the microphones from the two systems, along with small differences in the output intensity of the
speech items provided to the listeners.