Objective and Subjective Investigation on a Novel Method for Digital Reverberator Parameters Estimation

Reverberation is a well known effect that has an important role in our listening experience. A great deal of research has been devoted in the last decades aiming to artificially reproduce the reverberation effect exploiting a hybrid reverberation structure. In this context, several automatic procedures have been presented in the literature in order to derive the reverberator structure considering the mixing time evaluation and the minimization functions definition for the late reverberation device. Taking into consideration these aspects, a deep analysis of hybrid digital reverberator audio quality is here proposed, introducing a new parameter for the definition of the mixing time and two new cost functions for the definition of the late reverberation parameters. More in detail, starting from the considerations derived from a previous accurate approach based on the mel frequency cepstral coefficients, the new cost functions are based on the evaluation of the perceptual linear predictive and power normalized cepstral coefficients. Several results are reported, in terms of objective measure, performance analysis and subjective measures, taking into consideration different real impulse responses and various input stimuli and making a comparison with the state of the art. In particular, the obtained results show that a good accuracy can be achieved also considering a low number of coefficients, therefore improving the computational performance.