Objective To characterize the impulse noise exposure and auditory risk for youth recreational firearm users engaged in outdoor target shooting events. The youth shooting positions are typically standing or sitting at a table, which places the firearm closer to the ground or reflective surface when compared to adult shooters. Design Acoustic characteristics were examined and the auditory risk estimates were evaluated using contemporary damage-risk criteria for unprotected adult listeners and the 120-dB peak limit suggested by the World Health Organization (1999) for children. Study sample Impulses were generated by 26 firearm/ammunition configurations representing rifles, shotguns, and pistols used by youth. Measurements were obtained relative to a youth shooter’s left ear. Results All firearms generated peak levels that exceeded the 120 dB peak limit suggested by the WHO for children. In general, shooting from the seated position over a tabletop increases the peak levels, LAeq8 and reduces the unprotected maximum permissible exposures (MPEs) for both rifles and pistols. Pistols pose the greatest auditory risk when fired over a tabletop. Conclusion Youth should utilize smaller caliber weapons, preferably from the standing position, and always wear hearing protection whenever engaging in shooting activities to reduce the risk for auditory damage.

The DIAdvisor is an EC/FP7 funded project aiming at the development of a Blood Glucose prediction device which uses easily available information to optimise the therapy of patients with diabetes.

Objective-This study describes signals generated by .22 and .32 caliber starter pistols in the context of noise-induced hearing loss risk for sports officials and athletes.Design-Acoustic comparison of impulses generated from typical .22 and .32 caliber starter pistols firing blanks were made to impulses generated from comparable firearms firing both blanks and live rounds. Acoustic characteristics are described in terms of directionality and distance from the shooter in a simulated outdoor running track. Metrics include peak sound pressure levels (SPL), A-weighted equivalent 8-hour level (L eqA8 ), and maximum permissible number of individual shots, or maximum permissible exposures (MPE) for the unprotected ear.Results-Starter pistols produce peak SPLs above 140 dB. The numbers of MPEs are as few as five for the .22-caliber starter pistol, and somewhat higher (≤25) for the .32-caliber pistol.Conclusion-The impulsive sounds produced by starter pistols correspond to MPE numbers that are unacceptably small for unprotected officials and others in the immediate vicinity of the shooter. At the distances included in this study, the risk to athletes appears to be low (when referencing exposure criteria for adults), but the sound associated with the starter pistol will contribute to the athlete's overall noise exposure.Correspondence: Deanna K. Meinke Audiology and Speech-Language Sciences, University of Northern Colorado, Campus Box 140, Greeley, CO 80639, USA. Deanna.Meinke@unco.edu. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health. Declaration of interest:Jacob Soendergaard is an employee of G.R.A.S. Sound and Vibration, a manufacturer of sound measurement instrumentation used in this research study. Athletic events have historically been started by using loud acoustic signals (e.g. track and field races). A trumpet blow was used by officials of the ancient Olympic Games beginning in the sixth century B.C. to start the Stadion (running race). Eventually, firearms replaced the trumpet as the acoustic signal source for a variety of sporting events (e.g. track and field, swimming, speed skating, horse racing). Prior to the widespread ability to rapidly transmit signals through wired or wireless networks, the sound produced by a firearm blast provided a recognizable and brief signal that traveled rapidly for great distances. The signal is purposely chosen to be loud and audible to the athletes, officials, and audience. HHS Public AccessThe common use of firearms for the purpose of starting sporting events eventually led to the development of starter pistols, a signaling device that replicates the general shape of a handgun but uses only "blank" cartridges (i.e. cartridges containing only combustible material or containing a combination of combustible and non-combustible materials, but no bullet or projectile). The black powder produces smoke that signals the race officials to tri...

The international standard IEC 60318-4 specifies an occluded ear simulator for testing headphones, earphones, hearing protectors, hearing aids etc. The standard specifies a specific microphone type which limits the dynamic range of the coupler, such that it is not possible to measure very low levels or very high levels. Additionally, the standard 711 coupler is often interfaced to a pinna simulator incorporated in a Head and Torso simulator as per IEC 60318-7. This interface has traditionally been implemented as a cylindrical, straight ear canal simulator. This makes the fit of many modern in-ear headphones and hearing protectors problematic and unrealistic. By using low noise microphones instead of the standard microphones, the coupler can be used for measuring extremely low sound pressure levels such as noise floor, low level distortion or microphonics. Conversely, by using low sensitivity microphones, the coupler can be used for extremely high level measurements—useful for testing active and passive attenuation ratings of hearing protectors. Moreover, using a vast database of 3D human ear canal scans, a new pinna and ear canal simulator is proposed that will greatly improve measurement accuracy and repeatability on products going on or in the ear.