Recording anechoic gunshot waveforms of several firearms at 500 kilohertz sampling rate (original) (raw)
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Determining the Muzzle Blast Duration and Acoustical Energy of Quasi-Anechoic Gunshot Recordings
Journal of The Audio Engineering Society, 2016
Investigation of gunshot waveforms largely includes analyzing the muzzle blast. Generated by the combustion of gunpowder immediately after firing, these brief duration directional shock waves travel outward in all directions at the speed of sound. Features of these waveforms are analyzed to identify characteristics of a particular shot, for example, the combination of firearm type, ammunition, and orientation. This paper includes measured muzzle blast durations for several common firearms and calculation of the total acoustical energy during the muzzle blast period.
2016
the opportunity and invaluable guidance throughout this research. His dynamism, vision, sincerity and motivation have deeply inspired me. It was a great privilege and honor to carry out my work under his guidance. I am extremely grateful for what he has offered me not only as a mentor but also as a human being. I would also like to thank him for his patience, empathy, and most importantly, understanding me as a person. My Special thanks go to Prof. Steven Shaw for his support in gunshot recordings. I am extremely grateful to Angelo Borzino, for his support in the interpretation of recorded signals. I am extending my gratitude to Tyler Davis, for his assistance during the whole period. Finally, my thanks go to my parents and all my friends and staff of this department, who has directly and indirectly, supported me to complete the research work.
Gunshot Acoustics: Pistol vs. Revolver
2017
Audio forensic investigations may require interpretation of recordings containing gunshot sounds. These sounds are notable because of their impulsive nature: very high sound pressure and very short duration compared to other sounds relevant to forensic analysis. In this paper we examine the acoustical characteristics of muzzle blast sounds from two handguns: a Glock 19 pistol and a Ruger SP101 revolver. The muzzle blast sound of each handgun was recorded at several azimuth angles between 0 and 180 degrees with respect to the barrel using a quasi-anechoic methodology. Compared to the pistol, the revolver exhibits a more complicated acoustical pattern due to sound emanation from two sources: the cylinder-barrel gap and the muzzle.
Wideband Audio Recordings of Gunshots: Waveforms and Repeatability
2016
For the purposes of audio forensics research we have obtained multi-channel acoustical recordings of gunshots under controlled conditions for several firearms. The recordings are made using an elevated platform and an elevated spatial array of microphones to provide quasi-anechoic directional recordings of the muzzle blast. The consistency and repeatability of gunshot sounds are relevant to many areas of forensic analysis. This paper includes a description of the recording process and a summary comparison of the acoustical waveforms obtained from ten successive shots from the same firearm by an experienced marksman. Practical examples and applications are presented.
Advancing Forensic Analysis of Gunshot Acoustics
Journal of The Audio Engineering Society, 2015
This paper describes our current work to create the apparatus and methodology for scientific and repeatable collection of firearm acoustical properties, including the important direction-dependence of each firearm’s sound field. Gunshot acoustical data is collected for a wide range of firearms using an elevated shooting platform and an elevated spatial array of microphones to allow echo-free directional recordings of each firearm’s muzzle blast. The results of this proposed methodology include a standard procedure for cataloging firearm acoustical characteristics, and a database of acoustical signatures as a function of azimuth for a variety of common firearms and types of ammunition.
Measuring Recreational Firearm Noise
Sound Vibration, 2009
Recreational use of firearms in the United States is commonplace. It is estimated that approximately one-third of households in the U.S. own firearms. 1 There are 28 million Americans who consider themselves hunters, and 13 million went hunting in 2000. 2 Participation in shooting sports without the use of properly worn hearing protection exposes participants to high levels of impulsive noise that may cause hearing loss or tinnitus (ringing in the ear). Firearms may cause permanent hearing loss even after a single or a few unprotected exposures. The present study was initiated to gain a better understanding of the noise exposure created by contemporary firearms using state-of-the-art instrumentation and to ultimately increase our knowledge and awareness of this unique noise hazard.
Understanding Distance Shooting and the Type of Firearm from the Analysis of Gunshot Sounds
2016
In order to study gunshot sounds, experimental shootings were conducted in an open shooting range to record the sound of gunshots. The results were tabulated for a total of 168 gunshots. Shots were fired using pistols, revolvers, submachine guns, rifl es and shotguns in di fferent calibres from selected distances relative to the recording devices. Both a conventional sound level meter (SLM) and a measurement microphone were used. These were placed at selected points behind the shooting position and the sound of each shot was recorded. At the same time, the signal received by the microphone was transferred to a computer connected through an appropriate audio interface with a pre-amplifier. The peak amplitude of the gunshot was calculated in the accepted engineering units (dB) of sound pressure level. The shortest distance for the recordings was 9.60 m and the furthest was 38.40 m. The experiment was carried out using the following calibres: 6.35 mm, 7.62 mm Tokarev, 7.65 mm, 9 mm Sho...
Gunshots Sound Analysis, Identification, and Impact on Hearing
Particularly, I would like to thank Prof. Rafik Goubran for his support, guidance and enlightenment through all these years and Dr. David Lo for being a wonderful colleague, supervisor and friend. Without him, the thesis would not have been possible. My thanks also go to Master Corporal Alex Saumure; recording the data was simple with him taking charge of all the logistics and his ensuring that we had all the equipment. Finally, I would like to thank my love, Chantal Boutin. I am so lucky to have you by my side.
A study of acoustic waves generated by the shock wave of an antihail gun
Acoustical Physics, 2011
The processes of propagation of a shock wave generated by an antihail gun are analyzed. It is shown that a shock wave can reach an altitude of 100 km. The measurement results of the time dependence of variation in acoustic intensity and sound frequency for a vertically propagating shock wave are presented.
The direction of arrival of impulsive, wide- band audio signals, specifically of gunshot signals, is the main interest of this work. The Generalized Cross- Correlation (GCC) method, typically employed for wide- band signals, is used in a tetrahedral microphone array to estimate horizontal and vertical angles. An investigation on the performance of the scheme is carried out based on signals recorded in an open air, low-noise environment, and then repeatedly replayed in an open-air, noisy environ- ment, under controlled Direction of Arrival. To increase the accuracy of DoA estimates, the correlation function evaluated between each pair of microphones and used by GCC methods goes through an interpolation process. From this study, we have concluded that the GCC method can perform adequately in the task of estimating the DoA of a gunshot signal even in the presence of strong noise level and lower sampling frequency.