The time is usually recorded to hundredths of a second (centisecond), which is required by competitions in the International Practical Shooting Confederation.
Soon after Ron Bailey of Competition Electronics built a timer with an included microphone that was able to mark the time of each shot fired.
[4] 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.
[5] 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[6] such as small caliber rifles.
However, many shooters use a mobile app-based shot timer only for its par function when conducting dry fire practice in which there is no need to pick up the sound of gunfire.