  Perceptual modification of voice is an elusive goal. While non-experts can
modify an image or sentence perceptually with available tools, it is not clear
how to similarly modify speech along perceptual axes. Voice conversion does
make it possible to convert one voice to another, but these modifications are
handled by black box models, and the specifics of what perceptual qualities to
modify and how to modify them are unclear. Towards allowing greater perceptual
control over voice, we introduce PerMod, a conditional latent diffusion model
that takes in an input voice and a perceptual qualities vector, and produces a
voice with the matching perceptual qualities. Unlike prior work, PerMod
generates a new voice corresponding to specific perceptual modifications.
Evaluating perceptual quality vectors with RMSE from both human and predicted
labels, we demonstrate that PerMod produces voices with the desired perceptual
qualities for typical voices, but performs poorly on atypical voices.
