Difference Limen for Level of Music

A psychoacoustic experiment has been conducted to determine the difference limen (DL) of the level of music reproduced in a listening room. The effects of three factors on the DL were measured using up to twelve trained subjects. The factors were music motif (Mozart, Elgar, Smashing Pumpkins), listening level (50, 60, 65, 70, 80 dB, A-weighted Leq) and dynamic range. It was hypothesised that the DL would reduce with reduced dynamic range or increased listening level. However, both hypotheses are rejected: listening level was the only significant factor, with a mid-range level of 65 dB giving the lowest mean DL of 1.5 dB. This rises to a mean DL of 2.1 dB at listening levels of 70 and 80 dB. These figures are larger than has previously been assumed and are about the same size as the spatial standard deviation in strength across classical concert halls. The results should be of use to designers of concert halls, recording studios and other spaces for critical listening to music.