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.

HowLoud, NIOSH SLM, Decibel X and Decibel: dB meter compared on accuracy, price, privacy and reports.

How much ANC really takes off, what is left at 60, 85 and 100 dB, and whether it protects hearing.

Sperm whales, pistol shrimp, bats, bellbirds and howler monkeys ranked by decibels, with the water-versus-air catch explained.

Krakatoa, Hunga Tonga, rocket launches and the 194 dB limit of sound in air.

What 120, 150 and 190 dB do to the body, and why everyday sound cannot kill you.

Why 0 dB is not silence, the quietest room on Earth, and why digital audio is always negative.

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.