Loudness Discrimination Test

What it measures

This test estimates your intensity difference limen — the smallest difference in loudness you can reliably detect between two otherwise identical tones. It is a measure of how finely your auditory system resolves changes in sound level, sometimes expressed as a Weber fraction for loudness.

How it works

You hear two 1000 Hz tones played one after the other, separated by a short gap. One tone is slightly louder than the other; you simply choose which one — first or second — sounded louder. This is a two-alternative forced-choice task, the standard method in auditory psychophysics. After each answer an adaptive staircase narrows the loudness gap: when you answer correctly the difference shrinks, making the next pair harder, and when you miss it grows back. The gap converges on the smallest difference you can still hear, and the threshold is taken from the average of several turning points. In normal hearing this limen is roughly 0.5–1 dB at comfortable listening levels.

Tips for an accurate result

• 1Trust your first impression — Loudness differences are perceived almost instantly. Over-thinking a pair rarely helps — go with the tone that felt louder as it played.
• 2Guess when you genuinely can't tell — Near your threshold the two tones will sound the same. Guessing is expected and the staircase is designed for it; refusing to answer just stalls the test.
• 3Retest to check consistency — Because this measure depends on your headphones, volume, and room, a single run is only a rough estimate. Repeating under the same conditions gives a more trustworthy figure.