  Pitch scaling algorithms have a significant impact on the security of
Automatic Speaker Verification (ASV) systems. Although numerous anti-spoofing
algorithms have been proposed to identify the pitch-shifted voice and even
restore it to the original version, they either have poor performance or
require the original voice as a reference, limiting the prospects of
applications. In this paper, we propose a no-reference approach termed
PSVRF$^1$ for high-quality restoration of pitch-shifted voice. Experiments on
AISHELL-1 and AISHELL-3 demonstrate that PSVRF can restore the voice disguised
by various pitch-scaling techniques, which obviously enhances the robustness of
ASV systems to pitch-scaling attacks. Furthermore, the performance of PSVRF
even surpasses that of the state-of-the-art reference-based approach.
