THE PERCEPTIBILITY OF DIFFERENCES IN DEFINITION AND CLARITY IN LISTENING ROOMS

A study is presented on the detectability of differences of the definition of speech and of the clarity of music presented in listening rooms. To validate earlier results obtained using a simulated acoustic field, audibility tests were performed using a dummy head in an actual room. The values obtained in these tests for the limens of perception are in good agreement with those obtained using simulated fields, bearing in mind the uncertainties of subjective judgments. The investigations in an actual room thus confirm precisely the auditory tests conducted with synthetic signals. Looking for a practical application of the results as an indicator for determining the optimal dimensions of the ''seating zone'' of a room, we propose Delta C-80 approximate to +/- 2.5 dB and Delta C-80 approximate to +/- 3.0 dB as the limens of ''just perceptible differences'', where the quantities Delta C-50 and Delta C-80 represent the maximum permissible acceptable values of the differences in the measures of definition for speech and the measures of clarity for music.