We present a framework to optimize and generate Acoustic Reliefs : acoustic diffusers that not only perform well acoustically in scattering sound uniformly in all directions, but are also visually interesting and can approximate user-provided images. To this end, we develop a differentiable acoustics simulator based on the boundary element method, and integrate it with a differentiable renderer coupled with a vision model to jointly optimize for acoustics, appearance, and fabrication constraints at the same time. We generate various examples and fabricate two room-scale reliefs. The result is a validated simulation and optimization scheme for generating acoustic reliefs whose appearances can be guided by a provided image.