glossary
Integrated loudness describes the whole program; short-term loudness shows recent level.
LUFS-I means integrated loudness, the gated loudness value measured across the full song, episode, or program. LUFS-S means short-term loudness, usually measured over a moving three-second window.
Both use the LUFS scale, but they answer different questions: final delivery level versus what is happening right now.
A master can hit a reasonable integrated target while still having sections that feel too loud or too quiet. Short-term loudness shows those section-by-section changes.
If the chorus jumps too far or the verse disappears, LUFS-S can reveal the contrast that the final LUFS-I number smooths over.
Watch LUFS-S while balancing sections, then use LUFS-I for the finished file. Check true peak at the same time so loudness changes do not create delivery overs.
Meter Core shows integrated, short-term, and true-peak readings together for mix and master decisions.