WaveNODE: A Continuous Normalizing Flow for Speech Synthesis
Table 2: Comparison of synthesis speed. All models are benchmarked using a single RTX 2080Ti GPU.
['Model', 'Samples/sec']
We set the test tolerance of WaveNODE to 10−3. While WaveNet achieved the best result in the MOS test, it showed the worst performance on synthesis speed as it generates one sample point at a time (i.e., ancestral sampling). On the other hand, WaveNODE generated 51K samples/sec, which was a lot faster than WaveNet due to the parallel sampling process of flow operation. This suggests that WaveNODE is capable of generating audio samples in real-time even though WaveNODE has to solve complex ODEs in every flow operation. The sampling speeds of FloWaveNet and WaveGlow were the fastest since these models are not required to solve ODEs.