Echo-aware room impulse response generation
[ Paper | Code ]

Seongrae Kim1, Jae-hyoun Yoo2, and Jung-Woo Choi1
1School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
2Electronics and Telecommunications Research Institute (ETRI), Daejeon, Republic of Korea

overview

Abstract: In real-time applications, like interactive virtual reality environments, there is a significant need for low-complexity simulation of room impulse responses in highly complex virtual scenes, but this remains a challenging issue. In particular, simulating late reverberation using physically based acoustic modeling requires much computational effort, contrary to the early reflections that can be modeled by simpler techniques, e.g., the image source method. To tackle this computational complexity issue, we propose a neural network-based hybrid artificial reverberation framework (Echo2Reverb) that generates late reverberation from given early reflections. The proposed model can control both temporal texture and frequency-dependent energy decay, i.e., echo density and spectral energy distribution, of the generated reverberations by extracting spectral and echo-related features and filtering sampled sparse sequences and Gaussian noises using estimated features. To support the end-to-end training with controlled echo density, a differentiable approximation of the normalized echo density profile is proposed. We train and test the model not only for nearly diffuse but also distinct echoes prominent in late reverberations, such as with flutter echoes in narrow corridors. Evaluation results demonstrate that the proposed model can accurately reproduce frequency-dependent energy decay and temporal texture of a room impulse response using only early reflections.

Audio samples

# Type RIR waveform
w/ DR-NED
RIR Convolution
w/ percussion loop
Convolution
w/ female vocal
1 Ground truth
rir01_fig_0_GroundTruth
Echo2Reverb
rir01_fig_1_Echo2Reverb
Early reflection only
rir01_fig_2_EarlyOnly
2 Ground truth
rir02_fig_0_GroundTruth
Echo2Reverb
rir02_fig_1_Echo2Reverb
Early reflection only
rir02_fig_2_EarlyOnly
3 Ground truth
rir03_fig_0_GroundTruth
Echo2Reverb
rir03_fig_1_Echo2Reverb
Early reflection only
rir03_fig_2_EarlyOnly
4 Ground truth
rir04_fig_0_GroundTruth
Echo2Reverb
rir04_fig_1_Echo2Reverb
Early reflection only
rir04_fig_2_EarlyOnly