Absorbers and diffusers are two of the main design tools for altering the acoustic conditions of a room, semi-enclosed spaces and the outdoor environment. Their correct use is important for delivering high quality acoustics.This unique and authoritative text describes how to effectively measure, model, design, optimise and apply diffusers and absorbers. Surface diffusion is a relatively young subject area, and diffuser design, application and characterisation are new to practitioners and researchers, who may not have been exposed to this new information in their formal training. This book is a resource for new and experienced acousticians seeking an understanding of the evolution and current state of the art in diffuser research and practice. Absorption is a more established technology, and so the book blends traditional design with modern developments. By collecting the key aspects of absorbers in one text, the book offers new and experienced professionals an opportunity to understand this subject in more depth. This detailed book serves to cover the practical and theoretical aspects of absorbers and diffusers and is well illustrated, with examples of installations and case studies.