Stump Microphones and Snickometer: How Cricket Uses Sound in Broadcasting
The technology behind cricket's audio detection systems — the stump microphone (ambient sound at the wicket), the Snickometer (real-time audio waveform display), UltraEdge (advanced edge detection using video and audio synchronisation), and how these tools have changed what broadcasters and umpires can detect from the on-field sound environment.
The Stump Microphone
Stump microphones are small omnidirectional microphones embedded in the stumps at both ends of the pitch, transmitting live audio to the broadcast production unit. Introduced in English cricket broadcasting in the early 1990s, stump microphones capture the ambient sound environment at cricket's focal point — the crease area where ball meets bat, pad, and ground. The microphones pick up the crack of bat-on-ball, the thud of ball-on-pad, the sound of stumps being broken, and (controversially) the conversations between players, umpires, and wicketkeepers.
Stump microphone audio creates a more immersive experience for television viewers and has changed the public perception of on-field player behaviour — fans can hear sledging, tactical discussions, and reactions to decisions that were previously private. Some players have objected to stump microphone use on the grounds that it makes private conversations (including tactical planning) audible to opponents watching the broadcast. The ICC mandates stump microphone use in all major international broadcasts but has protocols about editing out inappropriate language.
The Snickometer
The Snickometer (originally developed by Alan Plaskett and introduced in cricket broadcasts in 1999) is an audio waveform display that shows the oscilloscope trace of the stump microphone's audio signal in real time. When a ball passes the bat, any contact (edge, glove, bat clipping pad) produces a characteristic spike in the audio waveform. The Snickometer displays this spike alongside the video footage, allowing viewers (and potentially umpires, in some DRS implementations) to see whether the ball made contact with the bat at the moment it passed.
The Snickometer is primarily a broadcast tool — its signal is displayed for viewers but is not directly integrated into on-field umpire decision-making or DRS. However, the Snickometer's visibility in broadcasts has influenced how caught-behind DRS reviews are perceived: if the broadcast shows a clear Snickometer spike at the point of bat-ball proximity, viewers immediately have an informed view of whether the edge occurred, often before any official DRS decision is communicated.
UltraEdge and DRS Integration
UltraEdge (developed by Hawk-Eye Innovations, the same company that produces ball-tracking technology) is an advanced caught-behind detection system that synchronises high-speed video with audio analysis. Unlike the simple Snickometer (audio only), UltraEdge uses the synchronisation of the video frame showing closest ball-bat proximity with the audio spike to provide a more definitive analysis. UltraEdge is integrated into the ICC DRS process for caught-behind reviews — third umpires use UltraEdge data as part of their decision analysis.
Frequently asked questions
Is the stump microphone feed edited before broadcast?
Yes — broadcast teams apply a delay (typically 5-7 seconds) to stump microphone audio, allowing production staff to cut the signal if players use extremely inappropriate language or discuss information that would be sensitive to broadcast (e.g., an injured player's condition). The delay also allows production to synchronise the stump microphone audio with video replay. Not all stump microphone content reaches the broadcast — production teams select clips that add entertainment value without creating controversy.
Can teams hear the broadcast stump microphone audio during the match?
No — teams do not have access to the live broadcast feed during a match. Their tactical discussions (when audible via stump microphone) are broadcast to viewers but not fed back to either team's dressing room. However, if a team's support staff is watching the broadcast on a television that is near the ground, there is a theoretical (and impractical) feedback path — but the 5-7 second broadcast delay and the general isolation of support staff during play makes this a non-issue in practice.
Do stump microphones affect the ball's contact sound?
Modern stump microphones are designed to minimise their impact on the stump itself. They are embedded in the hollow cavity of modern plastic and metal stumps (which are hollow for exactly this purpose) with the capsule at the top of the stump (where the bail sits). The microphone is entirely encased — it does not protrude or affect the stump's playing surface. The stump's acoustic resonance when hit by the ball actually amplifies the contact sound slightly, which is why stump microphone audio of stumps being hit sounds notably resonant.