The INTERFACES project explored how sound waves can be shaped and controlled using specially designed materials called acoustic metamaterials. The team developed both static and reconfigurable devices to steer and manipulate sound in real-time. Highlights include the invention of fluid- and magnetically-actuated materials that can adaptively reshape sound fields, and algorithms that enable high-speed 3D acoustic displays—even in complex environments. These breakthroughs have led to new ways of visualising and interacting with data using mid-air particle displays, and to noise control applications, including early work on wind farm noise mitigation. Two start-up companies—AcoustoFab and Metasonixx—were created to take these ideas into the real world, focusing on applications in advanced manufacturing and environmental acoustics. The project has resulted in over 25 high-profile publications and several patents, establishing a foundation for future technologies in interactive displays, adaptive sound environments, and sustainable energy infrastructure.