The volume deals in depth with sound in the audiovisual sector in its technical and expressive aspects, mainly for films and documentaries. Simone Corelli, Stefano Mainetti and Gilberto Martinelli, well-known professionals in the sector, tackle both the production and post-production sides, up to listening to the audience, also dealing with film music. The essay published by Lambda is embellished with a detailed chronology on the scientific and technological progress related to sound, and with original graphics and photographs. It is a work for experts but also for film enthusiasts and students. The preface is by Claudio Strinati.