Audiobook Spec Checker

Room tone length is not an exact number. It shifts depending on where you decide silence begins, because the last word fades rather than stopping. On one real file the tail measured 6.09 s, 5.19 s or 3.99 s depending on the threshold. Anything within a second of a ceiling is marked borderline rather than failed.

The noise floor is the quietest sustained second, not the quietest instant. A file that fades out passes through every level on the way down, so a single quietest moment lands wherever a measuring window happens to fall. Room tone is sustained; a fade is not.

Digital silence is excluded. A noise gate writes true zero, which would measure as an impossibly good number and tell you nothing about your room. Only real recorded quiet is measured, and the breakdown says how much of the file was gated. If a file is gated so hard there is no room tone left, it says so rather than inventing a figure.

Clipping cannot be measured past 0 dB. A browser clamps audio at full scale, so a clipped file reads as exactly 0.00 and never higher. The result says the file is clipped rather than pretending to know by how much.

A WAV or FLAC master is not a deliverable for most of these distributors, so it will fail their format check by design. The measured numbers still mean something.