TECHNOLOGY AREA(S): Ground/Sea Vehicles, Human Systems

ACQUISITION PROGRAM: MARCORSYSCOM (MCSC)

OBJECTIVE: Create technologies to improve communications, localization, and auditory preservation for combat and training scenarios. Develop digital signal processing and actuators (speakers and microphones) and apply the aforementioned technologies into a suitable Warfighter communication system(s). Optimize auditory detection and localization in helmet and in-ear communications in high- and low-noise environments. Demonstrate system efficacy�improved and clear communications in actual scenarios. The components must be rugged and usable in ground/maritime operations. Consider implementing noise monitoring without adverse effects on operational performance.

DESCRIPTION: Warfighters rely on their hearing to detect, identify, and localize sound sources and thus potential threats [Refs 2, 3]. Verbal communications (face-to-face and transmitted via radio) are crucial for mission success. Current communication systems compromise these abilities. Combat and training environments challenge Warfighter communications. The range of sound pressure levels encountered may vary from the audiometric threshold of hearing up to levels that may cause immediate auditory injuries. The sound pressure levels may vary rapidly across this range, providing no opportunity to don and doff hearing protection as the sound pressure level changes. Impulses may occur without warning.

An ideal communication and hearing protection system would enhance communications and localization/detection. The system would be able to filter or otherwise enhance incoming signals to preserve speech signals in the presence of noise. It would attenuate high-amplitude noises to safe levels, and automatically adjust gain and compression levels to protect the user from high noise exposure. It would allow the user to maintain situational awareness by detecting, identifying, and localizing sounds. The system would be robust enough to handle the adverse environments (e.g., moisture) and inherent rough handling that Warfighter equipment is exposed to [Ref 4]. It could include user adjustments to help eliminate some causes of hearing loss and could consider noise monitoring/dosimetry capabilities.

The communication system would consider modern, digital signal processing, with matched microphones and speakers (actuators) to overcome these challenges. Existing communication systems reduce intelligibility in the operational and training scenarios. The system must work in the current noise levels of 74 to 117 dBA, which are noise hazardous [Ref 1] and compromise current communications. ANSI S3.2-2009 (R2014) (Method For Measuring The Intelligibility Of Speech Over Communication Systems) would be an appropriate means of evaluation using the modified rhyme test [Ref 5]. ANSI S3.2-2009 (R2014) includes factors that affect the intelligibility of speech. The goal is to reduce in-ear noise levels below 85 dBA.

PHASE I: Determine the feasibility of developing and constructing communication technologies to provide clear communications between Warfighters both over radios and face-to-face in the presence/absence of high-level noise (continuous and/or impulsive). Develop a detailed design for a communication system that can meet the performance and the constraints listed in the Description. Create a report that must address level(s) of hearing protection provided by the communication system, which must consider both forward fit and back fit. Phase I includes the initial layout and capabilities, along with a descriptive plan to build the unit in Phase II.

PHASE II: Produce Warfighter communication system prototype hardware based on the Phase I proof-of-concept design for evaluation. Finalize the prototype design and validate improved communications for operational and training scenarios. Speech intelligibility tests shall be performed to confirm the communication improvements. Deliver six full prototype communication system kits for testing and evaluation at a location chosen by the Marine Corps/Navy. Phase II funding will not be provided until Institutional Review Board (IRB) approvals are obtained for human subject testing.

PHASE III DUAL USE APPLICATIONS: Construct production units suitable for certification for the Approved for Navy Use (ANU) List and develop marketing plans for a broad range of customers. Kits shall include all hardware required for modification of communication systems, operations, and maintenance procedures.

National and local police and security forces would benefit from this technology development. This technology is also applicable to first responders, in particular, fire fighters. Exposure of personnel to high noise levels, even with hearing protection, substantially increases the risk of Noise Induced Hearing Loss (NIHL). Hazardous noise exposure may be mitigated through administrative controls such as limiting an individual�s exposure time, use of hearing protection and engineering controls. The Occupational Safety and Health Administration (OSHA) requires elimination and or reduction of an acoustic hazard through engineering controls prior to implementing administrative controls or relying on personal protective hearing protection. Over the past decade, a large number of hearing loss claims (civilian) has been filed and millions of dollars have been compensated to workers due to NIHL. Workers in industries such as mining, oil fields, manufacturing, construction, and transportation are routinely exposed to high noise levels, and face similar communication challenges in high-noise environments. Reducing a worker�s occupational noise exposure is imperative from a safety and economics perspectives.

REFERENCES:

1. Casali and Clasing, �The Effects of Augmented Hearing Protection/Enhancement Devices o Auditory Situation Awareness for Military Ground Combat Applications.� PhD Dissertation. Virginia Tech, 2012

2. Garinther and Peters, �The Effects of Speech Intelligibility on Crew Performance in an M1A1 Tank Simulator.� U.S. Army Human Engineering Laboratory Technical Memorandum 11-90. 1990

3. Keller, et al, NSWCDD, August 2016, �Performance in noise: Impact of reduced speech intelligibility on
Sailor performance in a Navy command and control environment�, Hearing Research 349 (2017) 55e66

4. MIL-STD-810G, Department of Defense Test Method Standard: Environmental Engineering Considerations and Laboratory Tests. 2008
http://everyspec.com/MIL-STD/MIL-STD-0800-0899/MIL-STD-810G_12306/

5. ANSI/ASA S3.2-2009 (R2014), �Method for Measuring the Intelligibility of Speech over Communications Systems�, Acoustical Society of America. 2009
https://webstore.ansi.org/RecordDetail.aspx?sku=ANSI%2FASA+S3.2-2009+(R2014)

KEYWORDS: Communication System; Talk-through Circuitry; Localization; Hearing Protection; Noise Dosimetry