How do I use the Audio Loudness Meter?

1. Click the "Start" button to begin.
2. The Loudness Meter automatically loads a demo file when it first opens. You can simply click the button to play the demo.
3. To play your own audio file, click the "Browse" button to select a file from your device.
4. Next, click the orange "Start Test" button to see the Loudness output in real time as the file plays.

What information is shown on the Loudness Meter?

The Meter shows loudness measured in LUFS. Loudness is calculated for Momentary and Short Term LUFS and the output is also graphed on a circular scale. This output complies with the ITU-R BS.1770-2 LKFS loudness standards.

Quieter sounds show output closer to the center of the graph, while louder sounds push out towards the outer circumferance of the graph.

What are LUFS?

LUFS is an acronym that stands for loudness units full scale. "Loudness Units" are basically the same as decibels (dB), however they try to compensate for the way humans hear loudness based on the tonal balance of a sound. For example, if you test two files at the same decibel level, but varying equalizer (EQ) settings, the LUFS values may be different. "Full Scale" refers to the highest allowable level in fixed-point digital audio.

Momentary LUFS shows loudness values for a specific moment in time. It's equivalent to an RMS meter as found in audio workstations and "traditional" meters, but corrected for how you actually hear. Short Term LUFS shows a moving average of the last three seconds of Momentary values, which means less fluctuation that evens out some peaks and troughs.

Why do I need to care about LUFS?

In audio production, LUFS has become the unofficial standard for measuring loudness across diverse platforms, from streaming services to cinematic experiences. Whether crafting sound for Netflix originals or fine-tuning Dolby Atmos mixes, LUFS ensures optimal audio delivery.

However, LUFS isn't just about measuring loudness. It's also the backbone of consistency on music streaming platforms. For example, Spotify, YouTube, Tidal, Amazon and SoundCloud adjust tracks to -14 LUFS. Apple Music has a quieter target at -16 LUFS. Overall, an understanding of LUFS levels helps creators maintain uniform sound quality across different listening environments.

While the use of LUFS aims for consistent perceived loudness, nuances in arrangement and mastering can lead to subtle differences in volume between tracks with identical LUFS scores. To ensure your music resonates as intended, consider testing it at various normalization reference levels and comparing it to industry benchmarks.

Is volume the same as loudness?

Volume and loudness are often confused, however the two terms refer to very different concepts. Volume is a scientific measurement of the intensity or power of a sound, whereas loudness is a subjective concept based on a listener's personal perception of sound. Sound pressure level (SPL), frequency content and duration all affect how we perceive a sound's loudness.

For example, human hearing perceives loudness differently as the volume changes. At low volumes, bass and treble frequencies aren't perceived as loudly as midrange frequencies, so the mids dominate. At higher volumes, bass and treble are perceived much louder relative to the mids. As a result, changing the volume also changes the perceived frequency response. This is one reason why louder audio sounds better.