  In this paper, we propose a vocoder based on a pair of forward and
reverse-time linear stochastic differential equations (SDE). The solutions of
this SDE pair are two stochastic processes, one of which turns the distribution
of wave, that we want to generate, into a simple and tractable distribution.
The other is the generation procedure that turns this tractable simple signal
into the target wave. The model is called It\^oWave. It\^oWave use the Wiener
process as a driver to gradually subtract the excess signal from the noise
signal to generate realistic corresponding meaningful audio respectively, under
the conditional inputs of original mel spectrogram. The results of the
experiment show that the mean opinion scores (MOS) of It\^oWave can exceed the
current state-of-the-art (SOTA) methods, and reached 4.35$\pm$0.115. The
generated audio samples are available online.
