Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

No abstract

No abstract

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) March 20062. REPORT TYPE ARL-TR-3735 SPONSOR/MONITOR'S ACRONYM(S) 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) SPONSOR/MONITOR'S REPORT NUMBERS DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTThis experiment examined the relationship among team mental models, requesting or providing information, and teamwork behavior. Previous studies have suggested that similar mental models among team members lead to information and action being provided before they are requested, thus facilitating teamwork behavior such as communication, coordination, performance monitoring and backup, and adaptation. In this experiment, U.S. Army second lieutenants were presented with field scenario vignettes and asked to complete a written mental model of the most important task, biggest problems, and actions needed for themselves and other platoon leaders. Independent raters evaluated the participants while they were engaged in dialogue via text-based "chat," which was coded for "providing versus requesting" information or action, and teamwork behavior.Results showed good inter-rater reliability for the measures of mental models, anticipation ratio (providing versus requesting information or actions) and teamwork behavior, suggesting that these concepts were reliably measured. However, no significant relationships were observed among mental models, anticipation ratio, and teamwork behavior. Various methodological reasons are explored as possible explanations for the lack of relationships observed among the factors of interest. iii SUBJECT TERMS

As active noise reduction (ANR) becomes more common, the need has developed for the measurement of device attenuation, passive and active combined, for use in noise protection calculations. An experiment was conducted involving both REAT and MIRE measurements on five circumaural and two supra-aural ANR devices in two different laboratories. Subject selection and instruction were consistent with the ANSI S12.6-1997 Method B fitting paradigm for all measurements. MIRE was measured both using microphones mounted on canal-occluding plugs near the entrance of the canal (‘‘shallow MIRE’’) and using concha-mounted microphones with probe tubes extending near to the tympanic membrane and an unoccluded canal (‘‘deep MIRE’’); the latter measurements were done with the same device fitting trials as the REAT measurements. The two MIRE measurements were quite similar, with the shallow MIRE values typically better by margins of only 0.5 to 1.0 dB at all frequencies. A positive REAT minus MIRE difference at the lower frequencies consistent with the effects of physiological noise masking was observed. Various analyses of the data are presented and a recommendation is made for how ANR device total attenuation might be measured in a future standard as part of a hearing protector rating regime encompassing both passive and active devices.