Overall loudness perception properties under dichotic listening condition
Zhiyue Shao, Dongxing Mao · The Journal of the Acoustical Society of America · 2012
Dichotic listening conditions under which sound levels differ at the two ears are typical listening conditions, and there are yet no widely accepted results of binaural loudness summation. Researches show, the relationship between global loudness and interaural level difference (ILD) differs greatly for broadband noise and pure tone signals. Overall perceived loudness with interaural level difference (ILD) under different signal bandwidths was investigated through subjective listening experiment. In the subjective experiment, with the arithmetic mean of sound levels in both ears kept constant, the ILDs of dichotic signals ranged from 2dB to 12dB with 2dB step. Subjects were asked to match the overall loudness of dichotic test signals with that of diotic ones at the same center frequency and bandwidth. Signal of four bandwidths, which are 1/12, 1/6,1/3 and 1/1 octave were taken for the experiments. Results showed that the overall loudness of dichotic signals increases nonlinearly with ILD, and the narrower the signal bandwidth was, the faster the speed of the increase was. Comparison of subjective results with Moore's loudness model showed, deviation from Moore's model became larger as signal bandwidth narrowed.