Conceived and written by members of INA grm (Groupe de Recherches Musicales de l’Institut National de l’Audiovisuel), drawing on more than fifty years of experience in diffusing and presenting electroacoustic music in concert, the Acousmonium Handbook offers a synthetic exploration of the issues, techniques and methods applicable to acousmatic diffusion and sound spatialisation.As a manual, it provides numerous keys to designing a multiphonic sound diffusion system of the acousmonium type (loudspeaker orchestra) and addresses, step by step, all the stages of an acousmatic concert, from setting up the system to the diffusion of the works.Based on the observation that experimental music is still too often subject to traditional infrastructures and contingencies in concert settings, the handbook offers conceptual and practical guidance adaptable to a variety of contexts and systems in order to bring together as close as possible the concert experience and the act of listening.