| Reference | Level | Source |
|---|---|---|
| whisper | 30 dB | Reference |
Daytime and nighttime need context.
A small background sound can be noticeable in an otherwise quiet bedroom. Listen for repetitions and note whether it interrupted a rest period.
A daytime reading beside an active source is different from an overnight reading at your bed. Keep the microphone position and source distance in your notes. These examples do not reproduce your room or your phone’s calibration.
The scale is logarithmic.
30 dB is 0 dB above the 30 dB reference. On a sound-intensity scale that is approximately 1 times the reference intensity. It does not mean it sounds that many times louder, and this calculation does not certify a phone reading.
A number needs a record around it.
Note time, duration and context alongside the reading. Avoid identifying a source as a particular person unless you actually know. Keep personal notes on your device rather than entering them on this website.
Sources · whisper example · checked 2026-10-26
A few useful answers.
Is 30 dB too loud at night?
A single 30 dB value cannot decide that. Background sound, duration, frequency, room, sleep needs and the applicable rule all matter. Check the current ordinance and lease; a phone estimate is not legal certification.
What should I record beside a 30 dB estimate?
The local date/time and time zone, active duration, phone position, average and peak if available, what you heard and any uncertainty about its source. A phone cannot identify who caused it.