Microphone Since the introduction of shot timers with microphones in the 1980s, this has been the most common method of detecting shots until today. The timer then usually has one or more microphones and is usually carried by a referee or official, or attached to the shooter's belt. Many timers have the option to adjust their audio pickup sensitivity. Loud firearms like large
caliber rifles usually trigger the timer anyway, while less powerful firearms such as small caliber
5.6×15mmR (.22 LR) rifles often require the microphone to be adjusted to a more sensitive setting. If the pickup is set too sensitive there is a risk of detecting shots from other than the shooter intended to being measured or even speech.
Accelerometer There are also shot timers that attach to the firearm and detect shots using
accelerometers and
gyroscopes instead of using a separate hand-held device with microphones. These can also be used for data analysis of general movement of the firearm. Mantis was one of the first major manufacturers of such systems when they launched the MantisX system in 2015. Before that, Double Alpha Academy had launched the shot-timer watch ShotMaxx in 2013 after two years of development, which took advantage of
data fusion using a built-in microphone and accelerometer to detect shots. These types of shot timers can be particularly suitable for indoor ranges where there are a lot of gun sound reflections, or on quieter firearms such as small caliber rifles. == Bluetooth ==