Yoshinori Takahashi

Reverberation morphing using cepstrum decomposition

Reverberation morphing from an impulse response is an inevitable 3D-audio technology as well as reverberation rendering for an immersive communication network. This paper proposes a method for reverberation morphing by relocating the poles and zeros of the transfer function. It assumes that the distance of the pole/zero locations from the unit circle in the z-plane represents the reverberation condition for the transfer function. Exponential time-windowing moves the minimum-phase zeros, while the pole/zero relocation for the all-pass part is possible by the windowing after causal and non-causal cepstrum decomposition. We confirmed that the reverberation effects on the frequency response rendered by the proposed method were similar to those for recorded impulse responses in a variable reverberation room. This morphing is also applied to stable inverse filtering in a reverberant space.