A Night in Astley

A continuous, calibrated recording made by the measuring microphone in a rear garden on Withington Drive, Astley, beside Astley Business Park. The meter records everything that reaches the garden: the estate, the road, aircraft, birds, wind, neighbours. The chart tells you the measured level at every second, and the moments list says what can be heard at the marked times.

On this page you can hear it rather than imagine it: jump to any marked moment and read the meter while it plays. For context, the World Health Organisation's 1999 guidance for bedrooms at night is 45 dB LAmax for single events, and normal conversation sits near 60 dB.

Because no loudspeaker or headphone can reproduce an absolute sound level. Your volume control decides how loud the playback is; the readout shows what the calibrated meter measured at that second. The numbers are the evidence, and the audio is what they felt like.

Both lines are the approved planning assessment's own figures for this location. The 34 dB line is the night-time background level its baseline survey measured here before the estate was built; read the average trace against it. The 51 dB line is the loudest level it predicted outside the nearest bedroom windows at night with its mitigation in place; read the maximum levels against it, and anywhere the night went above it shows in red. The big number totals distinct exceedances of that 51 dB prediction up to the playhead: a run of seconds at or above the line counts once, a new exceedance is counted only after at least ten seconds back below it, and sections identified by ear as something other than the estate, an aircraft or the dawn chorus, are greyed on the chart and left out. One caveat, stated plainly: the prediction is for first-floor window height, 4.0 m, and the microphone stood at 2.5 m, which understates what reaches the bedrooms, so the comparison is conservative.

Yes. The level data downloads are licensed CC BY 4.0: use them freely and credit Murray Acoustics. Broadcast clips and stills are available for the press, and the whole player can be embedded on any site with one line of HTML. The links and the embed code are in the data section above.