Guest Post by Tony Edwards
As a musician, and having worked around recording studios and concert venues large and small since I was little more than a kid, you learn very quickly that in some environments you’re going to have a good night, and in others you’re going to face an uphill struggle.
Playing gigs in village halls was always likely to be tough – hard surfaces with the sound confused by multiple reflections, crowd hugging the walls. Low ceilinged clubs with soft furnishing and people right up to the stage were a sound man’s dream. But too, this is a rock musician’s best environment – because the sound of an audience itself has a massive psychological impact on how we as musicians perform.
What has this got to do with football you’re starting to ask? It’s the phenomenon of 1/r². Sound Pressure levels are inversely proportional to the square of the distance from the source. Sound pressure, compressions in the air, is how the human ear receives audio information.
In 2011, an experiment was carried out by the Press Association Sport into how loud football stadiums actually were. Seated in the stand they were given a device to measure the average Decibel level in the first 60 seconds after kickoff. West Ham scored a very respectable 81dB, 7th highest in the Premier League.
Let’s assume that the front seats at Upton Park were an average of 3m from the pitch. The pitch was 64 metres wide, which makes the shortest distance to the centre probably about 35 metres. At the London Stadium, that distance probably increases by about 15 metres, as the pitch is 4m wider and the closest seat to the centre circle (block 138) is about 10 metres further away than the closest West Stand seat at the Boleyn. But the gentle rake of the seating takes most people much further away than that – sight lines are good, but distances are way longer.
Suddenly we see how 1/r² reduces the sound pressure level (SPL) on the pitch, that SPL falls off very quickly as the distance increases – the graph of this looks like a ski slope. Doubling distance reduces Sound Pressure by 75%. But that cannot be the whole story – because accounting for increased numbers, the stadium shouldn’t exactly be quiet.
Frequency plays a part too. Low frequencies have long wavelengths and travel well, higher frequencies do not. Perception of ‘loudness’ is linked to ‘presence’ in the sound – a phenomena based in the higher frequency range. As those higher frequencies suffer more amplitude loss to the environment over distance than do low frequencies, the sound loses a perception of intensity as well as measured volume. Higher frequencies do reflect better, and at the Boleyn the roof helped to reflect them down towards the pitch. But the new stadium roof is higher, so the distances for reflected sound to travel are further and 1/r² comes into play yet again.
The psychology of this is based on expectations. As the home team, you’re expecting the roar of the crowd at your back. 50,000 people v 2,000, that’s your home advantage. When it seems subdued ( including the effect of ‘presence’ decay) it’s like something vital has been lost. Conversely, the away team expects that hostile environment, but when it isn’t there this acts as mental boost. Sound has been used as a psychological weapon in siege situations, to batter the enemy into submission. For musicians however, the noise of the crowd raises the adrenaline, heightens awareness and boosts energy levels, because that’s what our minds tell us we need, it’s how our psychology works. We are the ‘home team’ in this situation.
Even in the seats, does the LS sound as loud as the Boleyn? I don’t think so . You can see everyone is singing ‘Bubbles’, but the sound seems to disappear into the openness of the bowl as the early reflections don’t return because of the shape and size of the place. That in turn affects us too, further reducing our effectiveness due to a feeling that the ‘atmosphere’ is dampened. I’m told it’s a great venue for Rock Concerts, the sound is clear right around the stadium. That would make perfect sense because you don’t want sound reflection at a gig. That’s a nightmare for music, tuning it into garbled mush. However, because the crowd is also on the pitch, the musicians feel no detriment either – distance to the audience is reduced.
So the physics of sound and the psychology of expectations linked together show one way in which home advantage at the London Stadium is potentially lost. While this is no excuse for poor performances, it might go some way to explaining the slow starts to games, and why the London Stadium’s hugely increased capacity hasn’t generated a ‘fortress’ environment.
It’s all about proportionality – it’s about 1/r²