What is the minimum change in sound pressure level required for a "just noticeable" change?

The minimum change in sound pressure level that is typically regarded as a "just noticeable" difference (JND) for human hearing is around +/-3 decibels (dB). This threshold reflects the smallest variation in sound level that an average listener can detect under normal listening conditions.

A change of 1 dB or 2 dB is often too subtle for a typical listener to perceive reliably, which means those levels wouldn’t be considered significant or noticeable by most people. On the other hand, a change of +/-5 dB is considerably more apparent and would likely be recognized easily by listeners, but that goes beyond the threshold for a just-noticeable change. The +/-3 dB threshold represents the limit where most people can start to distinguish differences in sound levels, making it the standard benchmark in audio engineering and acoustics for the perception of sound.