Guides to Decibels, Noise and Hearing

Short, practical answers written around the questions people ask a decibel meter: how loud is too loud, how to measure it, and what the numbers mean.

The dB scale in plain English: why it is logarithmic and what 0 dB, 60 dB and 120 dB mean.

The 85 dB rule, the exposure table and what it means for headphones, concerts and sleep.

How accurate a phone microphone is, how to hold and calibrate it, and its limits.

Where to measure, what to log and typical legal limits before you complain.

A, C and Z weighting: what they filter, when to use each and why the numbers differ.

Budget meters vs Class 2 vs Class 1: what you get for the money and when it matters.

The five features that separate a real sound meter app from a gauge with a needle.

Looking for a specific level? Every value from 30 to 140 dB has its own page under How loud is…, and the decibel chart lists them all in one table.