Contribution
Frequency- and angle-dependent source models of muzzle blasts close to the gun
* Presenting author
Abstract:
In determining hearing exposure during shooting, weapon blasts in the vicinity of the muzzle must be analysed. In addition to measurement-based determination, these sounds can also be synthesized.For this task, angle-dependent source models are for example defined in the LeitGeStand. There, the directivity of a weapon class is modelled with a scalar, angle-dependent amplification factor, called the eccentricity. Among other things, this neglects the angle-dependent changes in the frequency spectrum of the weapon bang. When determining the hearing load this can lead to significant discrepancies between synthesized and measured shooting signals. This article presents two alternative approaches to describe the frequency-dependent directivity of a muzzle blast. The first approach is based on the Weber bang model in approximation to DIN EN 17201-2. In contrast to the standard, here the angle-dependent Weber radii and peak level are determined separately by a cosine transformation. The second model describes a spherical harmonics source. Depending on the input data, this model provides very detailed reconstructions of measured muzzle blasts.The presented source models are evaluated close to the muzzle. The evaluation is performed using the AHAAH model - a hearing damage prediction model - as well as classical level parameters.