Our brains often trick us into hearing what we expect to hear.¹

Louder often sounds better, even when it isn't.²

These are known and common problems, for which blind, level-matched listening tests can be helpful.

Blind Listening Test is a free web-based and VST3/AU plugin that automatically matches the perceived loudness (LUFS) of up to 10 audio files at a time. It lets you hide the names and waveforms while you randomize the order and compare.

Unlike a signal's peak level measured in dBFS (Decibels relative to Full Scale), LUFS (Loudness Units relative to Full Scale) approximates what we hear by weighting frequencies the way the ear does, averaged over time.

Blind Listening Test uses the ITU-R BS.1770³ standard to measure the loudness of each file in LUFS.⁴ The files are then matched to the quietest of the group, and set so the loudest peak across all files is no higher than −1 dBFS. You can export the level-matched files with their names hidden (as A.wav, B.wav, etc.) and reveal the names later in either the web version or the plugin.

Use the web-based version or download the plugin. Add files, click Match LUFS, and then hide the names with Blind/Shuffle.

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