Directional sharpness perception under different listening conditions

The assessment of sounds using psychoacoustic parameters is important in many areas. For the binaural case, it is not sufficiently clear how the characteristics of both ear signals have to be combined so that they best reflect the binaural percept. In the case of the auditory sensation of sharpness, this is particularly unclear due to limited empirical data on the perception of sharpness in dichotic listening conditions. To expand the empirical database and allow discussion on calculation methods for binaural sharpness and the derivation of representative metrics reflecting the binaural percept, two listening experiments were designed and conducted. The participants evaluated a series of signals for their sharpness, which were presented as real sound sources in an anechoic chamber via loudspeakers and as virtual sound sources via headphones from different sound source positions in the horizontal plane. Paired comparison and rating scale methods have been used to collect the data. Both experiments on sharpness revealed a tendency towards decreasing sharpness perception across all lateral positions. In contrast to maximum sharpness values of the ipsilateral side, arithmetic and quadratic averaging (mean and RMS values) of sharpness calculated according to the Aures method reflected the listening test results well and appear to be promising approaches for determining a binaural single value for most of the considered signals. Monaural signals and signals with several sound sources showed particular abnormalities in the listening test, some of which cannot be explained well.