Peak decibel readings measure the sound system as much as the crowd

Noise records make good copy and poor evidence, because a low roof and a strong public address beat an honest full house.

A record gets set, the club posts the number, and the number is treated as a statement about the supporters. It is mostly a statement about architecture. Sound in an enclosed bowl reflects off a low roof back down onto the microphone, and the same forty thousand people in an open ground with the stands set back from the touchline will produce a reading many units lower while doing exactly the same work with their lungs.

Then there is the placement question nobody asks. Where was the meter? Hang it under an overhang near the singing section and you get one answer. Put it at the halfway line in the open and you get another, and the two are not comparable in any sense that would survive a physics lesson. Decibels are logarithmic, so a small edge in the reading corresponds to a large gap in energy, and it also means the difference between two grounds can be manufactured by moving a device fifteen yards.

I care about this because the number has started to carry commercial weight. Atmosphere is now part of what a league sells to a broadcaster, and clubs know it. If the metric is peak volume, the cheap route to a good metric is a better amplifier and a compere with a microphone, not a supporter culture. That is a bad incentive and it is already visible in grounds where the loudest moment of the evening is a prompt rather than a response to anything on the pitch.

What the effect on players and officials turns on is different anyway. Sustained noise degrades the headset link between the referee and his assistants, and it does so at frequencies that overlap with speech. It is not the peak that ruins a communication. It is the ten minutes of continuous mid-range roar under which nobody can hear a word. A whistle cuts through because it sits above that band, which is exactly why whistles are pitched where they are.

Measure the sustained level. Publish where the meter was. And if a club wants to claim the loudest ground in the country, let them prove it with an away support that has been given a corner with a roof over it, because that, more than anything an amplifier can produce, is what makes a place feel dangerous.