In the early twentieth century, acoustic shells were primarily conceived as permanent structures, generally made in reinforced concrete. Architects like Candela and Niemeyer exploited the high density and plasticity of concrete to realise forms that could reflect sound efficiently. However, building doubly-curved shapes required laborious construction methods, including using complex and wasteful formworks. This paper presents the development and application of a computational workflow for the design and fabrication of acoustic concrete shells. The workflow allows controlling the shape of discrete, curved panels that can be assembled into continuous surfaces. The panels are designed to comply with the robotic fabrication requirements of a novel Parametric Adjustable Mould (PAM) technology and assembled to create shells that satisfy a set of acoustic requirements. The technology is used to fabricate custom curved concrete panels using a single mould frame that reduces waste in concrete formwork.