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(1) determine if untrained, normal-hearing listeners could learn, with regimented practice trials, to localise a dissonant tonal complex while wearing electronic hearing protectors and achieve equivalent performance to the unoccluded ear, (2) determine if different protector designs affect the localisation learning curve, and (3) determine if a sequential training regimen could be used to determine whether a device is not amenable to training effects. All subjects completed paired training and testing trials, in 12 Learning Units (LU), first with the open ear., then half with device A, a US Army TCAPS (INVISIO® X50), and the other half with device B (a prototype). Both groups then finished with the opposite device. Ten subjects participated, with thresholds below 25 dBHL, bilateral symmetry below 15 dBHL, and naivety with electronic protectors and localisation testing. Subjects eventually approached their open ear capability with device A, but never reached equivalent open ear nor asymptotic performance with device B. Depending upon a protector's sound transduction, frequency response, and other characteristics, different amounts of training are required to adapt. The training protocol has value in determining device acceptability based on the training burden required, especially when mission-related localisation performance is important. [ABSTRACT FROM AUTHOR]

(1) determine if untrained, normal-hearing listeners could learn, with regimented practice trials, to localise a dissonant tonal complex while wearing electronic hearing protectors and achieve equivalent performance to the unoccluded ear, (2) determine if different protector designs affect the localisation learning curve, and (3) determine if a sequential training regimen could be used to determine whether a device is not amenable to training effects. All subjects completed paired training and testing trials, in 12 Learning Units (LU), first with the open ear., then half with device A, a US Army TCAPS (INVISIO® X50), and the other half with device B (a prototype). Both groups then finished with the opposite device. Ten subjects participated, with thresholds below 25 dBHL, bilateral symmetry below 15 dBHL, and naivety with electronic protectors and localisation testing. Subjects eventually approached their open ear capability with device A, but never reached equivalent open ear nor asymptotic performance with device B. Depending upon a protector's sound transduction, frequency response, and other characteristics, different amounts of training are required to adapt. The training protocol has value in determining device acceptability based on the training burden required, especially when mission-related localisation performance is important. [ABSTRACT FROM AUTHOR]

Objective: To design a test battery and conduct a proof-of-concept experiment of a test method that can be used to measure the detection performance afforded by military advanced hearing protection devices (HPDs) and tactical communication and protective systems (TCAPS).Design: The detection test was conducted with each of the four loudspeakers located at front, right, rear and left of the participant. Participants wore 2 in-ear-type TCAPS, 1 earmuff-type TCAPS, a passive Combat Arms Earplug in its “open” or pass-through setting and an EB-15LE™ electronic earplug. Devices with electronic gain systems were tested under two gain settings: “unity” and “max”. Testing without any device (open ear) was conducted as a control.Study sample: Ten participants with audiometric requirements of 25 dBHL or better at 500, 1000, 2000, 4000, 8000 Hz in both ears.Results: Detection task performance varied with different signals and speaker locations. The test identified performance differences among certain TCAPS and protectors, and the open ear. Conclusions: A computer-controlled detection subtest of the Detection-Recognition/Identification-Localisation-Communication (DRILCOM) test battery was designed and implemented. Tested in a proof-of-concept experiment, it showed statistically-significant sensitivity to device differences in detection effects with the small sample of participants (10). This result has important implications for selection and deployment of TCAPS and HPDs on soldiers and workers in dynamic situations. [ABSTRACT FROM PUBLISHER]

Objective: To determine if training with electronically-modulated hearing protection (EMHP) and the open ear results in auditory learning on a horizontal localization task. Design: Baseline localization testing was conducted in three listening conditions (open-ear, in-the-ear (ITE) EMHP, and over-the-ear (OTE) EMHP). Participants then wore either an ITE or OTE EMHP for 12, almost daily, one-hour training sessions. After training was complete, participants again underwent localization testing in all three listening conditions. A computer with a custom software and hardware interface presented localization sounds and collected participant responses. Study sample: Twelve participants were recruited from the student population at Virginia Tech. Audiometric requirements were 35 dBHL at 500, 1000, and 2000 Hz bilaterally, and 55 dBHL at 4000 Hz in at least one ear. Results: Pre-training localization performance with an ITE or OTE EMHP was worse than open-ear performance. After training with any given listening condition, including open-ear, performance in that listening condition improved, in part from a practice effect. However, post-training localization performance showed near equal performance between the open-ear and training EMHP. Auditory learning occurred for the training EMHP, but not for the non-training EMHP; that is, there was no significant training crossover effect between the ITE and the OTE devices. Conclusion: It is evident from this study that auditory learning (improved horizontal localization performance) occurred with the EMHP for which training was performed. However, performance improvements found with the training EMHP were not realized in the non-training EMHP. Furthermore, localization performance in the open-ear condition also benefitted from training on the task. [ABSTRACT FROM AUTHOR]

Objective: To determine the effects of current hearing protection/enhancement devices (HPEDs) and tactical communications and protection systems (TCAPS) on auditory detection and identification of three critical military signals associated with potential 'threats.' Design: Utilizing a 6 × 3 within-subject experimental design, 24 normal-hearing Virginia Tech Reserve Officer Training Corps (ROTC) cadets and active duty soldiers participated. Study sample: Five HPEDS and TCAP devices plus the open ear were tested. On each trial, either wearing a device or with open ears, subjects walked along a 3000-foot line of discrete distance markers toward the auditory threat, which was not visible but still within line-of-sight over flat terrain, stopping to listen when instructed. On approach to the threat, the linear distance at first detection was measured, followed by a continued approach until positive identification occurred. Then the subject reversed direction, retreating away from the threat until detection was lost. Results: ANOVA and post hoc tests were applied to determine statistically-significant differences among HPEDs, TCAPS, and the open ear on the objective detection and identification distance measures. Conclusions: The results have serious implications for selection of HPDs, HPEDs, and TCAPS for applications where preservation of auditory situational awareness via the fundamental detection and identification tasks are essential. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented which discusses topics within the issue including various aspects of small caliber firearm noise exposures, firearm noise that is not typically experienced by persons using firearms at a target range or when hunting, and noise exposure risks.

The article offers several articles published in the issue from the 2018 Annual Conference of the National Hearing Conservation Association which includes cochlear synaptopathy, changes in otoacoustic emission from firearm noise exposure and noise control engineering role in several applications.

Objective: To investigate the effect of controlled low-speed wind-noise on the auditory situation awareness performance afforded by military hearing protection/enhancement devices (HPED) and tactical communication and protective systems (TCAPS).Design: Recognition/identification and pass-through communications tasks were separately conducted under three wind conditions (0, 5, and 10 mph). Subjects wore two in-ear-type TCAPS, one earmuff-type TCAPS, a Combat Arms Earplug in its ‘open’ or pass-through setting, and an EB-15LE™ electronic earplug. Devices with electronic gain systems were tested under two gain settings: ‘unity’ and ‘max’. Testing without any device (open ear) was conducted as a control.Study sample: Ten subjects were recruited from the student population at Virginia Tech. Audiometric requirements were 25 dBHL or better at 500, 1000, 2000, 4000, and 8000 Hz in both ears.Results: Performance on the interaction of communication task-by-device was significantly different only in 0 mph wind speed. The between-device performance differences varied with azimuthal speaker locations.Conclusions: It is evident from this study that stable (non-gusting) wind speeds up to 10 mph did not significantly degrade recognition/identification task performance and pass-through communication performance of the group of HPEDs and TCAPS tested. However, the various devices performed differently as the test sound signal speaker location was varied and it appears that physical as well as electronic features may have contributed to this directional result. [ABSTRACT FROM PUBLISHER]

Objective: A controlled field experiment was conducted to evaluate localization of suprathreshold gunshot reports (from blank cartridges) with four hearing protection-enhancement devices (HPEDs) in comparison to the open ear with ambient outdoor noise and in 82 dBA diesel military heavy truck noise. Design: Five measures of localization accuracy and response time for eight shooter positions in azimuth were measured. Study sample: Nine normal-hearing and four impaired-hearing participants were tested. Results: Statistical analysis showed worse accuracy and response time performance with the electronic earmuffs (Peltor Com-Tac II™ in full gain position) than with the other tested HPEDs (Etymotic EB 1 and EB 15 High-Fidelity Electronic BlastPLG™ electronic earplugs, both set to Lo gain positions; and 3M Single-Ended Combat Arms™ passive earplug in level-dependent, 'open' position). Performance with all HPEDs was worse than that with the open ear, except on right-left confusions, in which the earmuff stood alone as worst, and in response time, for which the EB 1 was equivalent to the open ear. There was no significant main effect of noise on performance. Hearing impairment increased right-left confusions. Subjective ratings related to localization generally corroborated objective localization performance. Conclusions: None of the tested HPEDs preserved 'normal' localization performance. [ABSTRACT FROM AUTHOR]

Objective: Design an optimised auditory azimuth localisation training protocol by: (1) differing the number of training stimuli presentations to determine the highest angular accuracy achieved in the fewest training sessions, (2) evaluating the presence of training transfer from a broadband stimulus to untrained military-relevant stimuli and (3) measuring the effect of differing training strategies on localisation accuracy. Design: Two pilot studies of 18 and six subjects, respectively, determined the number of presentations and type of stimuli to be included in a localisation training experiment that evaluated different training strategies. In the pilot studies, participants trained using eight Learning Units (LU) and then tested using untrained stimuli. In the main experiment, 40 participants completed eight LUs using four different learning strategies, with 10 participants randomly assigned to each condition. Sample: All participants were ages 18–42 normal-hearing listeners with thresholds not exceeding 25 dB HL and asymmetry not exceeding 15 dB HL. Results: Transfer of training occurred using three of the four untrained stimuli. The training strategy that resulted in the highest localisation accuracy involved active participation. Conclusions: Training with a broadband stimulus transfers to untrained broadband stimuli. Training involving the active participation strategy resulted in the greatest localisation accuracy. [ABSTRACT FROM AUTHOR]

Objective: Design an optimised auditory azimuth localisation training protocol by: (1) differing the number of training stimuli presentations to determine the highest angular accuracy achieved in the fewest training sessions, (2) evaluating the presence of training transfer from a broadband stimulus to untrained military-relevant stimuli and (3) measuring the effect of differing training strategies on localisation accuracy. Design: Two pilot studies of 18 and six subjects, respectively, determined the number of presentations and type of stimuli to be included in a localisation training experiment that evaluated different training strategies. In the pilot studies, participants trained using eight Learning Units (LU) and then tested using untrained stimuli. In the main experiment, 40 participants completed eight LUs using four different learning strategies, with 10 participants randomly assigned to each condition. Sample: All participants were ages 18–42 normal-hearing listeners with thresholds not exceeding 25 dB HL and asymmetry not exceeding 15 dB HL. Results: Transfer of training occurred using three of the four untrained stimuli. The training strategy that resulted in the highest localisation accuracy involved active participation. Conclusions: Training with a broadband stimulus transfers to untrained broadband stimuli. Training involving the active participation strategy resulted in the greatest localisation accuracy. [ABSTRACT FROM AUTHOR]