Is the hum from the data centre more than a dBA reading shows?
Most noise limits are written in dBA, which discounts the low-frequency rumble that cooling fans, generators and turbines produce. Check your readings against the published screening methods in under a minute. No sign-up, and nothing you enter is stored.
Take two readings of the same sound, at the same time and place: one A-weighted (dBA) and one C-weighted (dBC). Many sound-level meters switch between the two.
Enter one-third-octave Leq readings, measured indoors where the noise is heard. Leave a band blank if you have no reading for it.
Turn this into evidence: the LFN Evidence Report
A PDF with your readings, the band-by-band chart and table, the method and its sources, a measurement log, and a letter you can adapt for your council or the operator. USD 39, emailed within a few minutes.
How to get useful readings
- Measure inside, where the noise bothers you, with windows closed.
- Switch off fridges, fans and other sources nearby, or note them.
- Average over a few minutes (Leq) at the times it is worst, including at night.
- Phone apps are a starting point, but most phone microphones are not accurate at low frequencies.
Free alerts: new cases and rules
A short weekly email when a new data-centre noise lawsuit, violation notice or ordinance is added to the tracker. Nothing is sent in weeks with nothing new.
Why dBA is not enough
A-weighting was designed to mimic how the ear hears quieter sounds, so it turns the low end down sharply. A sound can meet a dBA limit and still be a constant, intrusive hum. The World Health Organization's 1999 guidelines say that if the C-weighted level is more than 10 dB above the A-weighted level, a frequency analysis should be done. The UK Government's procedure for low-frequency noise complaints (DEFRA NANR45) then compares each frequency band from 10 to 160 Hz with a reference curve, which is what the full screen does.
In a 2026 federal lawsuit over noise from a gas-turbine plant powering data centres, residents' readings reached 70 dBA, and the complaint said C-weighted readings would likely be significantly higher. See the tracked cases or read the method and its limits.