What Is Loudness in Audio?

Loudness vs volume: the key distinction

Volume typically refers to the amplitude of a signal at a given moment — how high the meter reads right now. Loudness is a psychoacoustic measure that models how human hearing perceives sustained audio over time. Two recordings with identical peak levels can feel very different in perceived loudness, because loudness depends on frequency content and duration as well as amplitude.

A single short drum hit might peak at -3 dBFS but feel quiet because it's brief. A sustained, heavily compressed vocal track might peak at -6 dBFS but feel overwhelmingly loud because the compression keeps the level constantly high. Volume meters don't capture this difference. Loudness meters do.

How loudness is measured: LUFS

LUFS stands for Loudness Units relative to Full Scale. It's a standardised measurement defined by the ITU (International Telecommunication Union) in standard BS.1770, designed to correlate with how humans actually perceive loudness.

There are three related measurements you'll encounter:

• Integrated LUFS:The average loudness of the entire file from start to finish. This is the number platforms use for normalisation. For a track or podcast episode, this is the key figure.
• Short-term LUFS:Average loudness over the last 3 seconds — useful for monitoring during mix and mastering.
• True peak:The actual peak level of the audio, accounting for inter-sample peaks that standard peak meters miss. Most platforms specify a maximum true peak limit to prevent distortion during their transcoding.

Streaming platform loudness targets

Every major streaming platform measures the integrated loudness of your upload and adjusts playback volume to match their target. Upload something louder: they turn it down. Upload something quieter: they turn it up (or leave it as-is, depending on the platform).

Targets can vary slightly by region or update. Always check the platform's current technical specifications before final mastering.

The loudness wars — and why they ended

Through the 1990s and 2000s, a competitive escalation played out in the music industry. Radio stations used compressors and limiters to broadcast music louder than competitors. Mastering engineers responded by pushing masters harder. Labels demanded the loudest possible master. The result was a decade of increasingly compressed, dynamic-free music where everything was loud — and therefore nothing felt loud, because there was no contrast.

When streaming platforms introduced loudness normalisation, the incentive for extreme loudness evaporated. If Spotify turns your -7 LUFS master down to match its -14 LUFS target, you've sacrificed dynamic range for no gain. Modern mastering practice has gradually moved back toward louder targets (-14 to -10 LUFS for electronic music is common, while classical and acoustic music sits closer to -18 to -23 LUFS) because the format allows it.

What this means when you export audio

For music: aim for a target loudness that suits your genre and won't be excessively reduced by streaming platforms. -14 LUFS integrated with a true peak of -1 dBTP is a broadly safe starting point for most platforms.

For podcasts: -16 LUFS is the widely recommended target for spoken-word content. Some hosts and apps use their own normalisation, but aiming for -16 LUFS with a -1 dBTP true peak limit gives you a clean, consistent baseline.

For video (YouTube): -14 LUFS. YouTube normalises to that target; submitting at exactly that level means your audio arrives at listeners without adjustment.