The revised edition of this book offers an expanded review of acoustic metamaterials; novel materials which can manipulate sound waves, surface Rayleigh waves and water waves, in surprising ways, which include collimation, focusing, negative refraction, passive and active cloaking, sonic screening and extraordinary transmission. It covers both experimental and theoretical aspects of acoustic and elastic waves propagating in structured composites, with a focus on effective properties associated with negative refraction, lensing and cloaking. Updated chapters cover filtering effects, extraordinary transmission, sub-wavelength imaging via tomography or time-reversal techniques, cloaking via transformation acoustics, elastodynamics, and acoustic scattering cancellation. For this revised edition, six new chapters have been introduced to reflect recent developments in experimental acoustics and metasurfaces including acoustic impedance gratings and mirror symmetric metamaterials, phononic subsurfaces, time-modulated and topological crystals. The latter two are illustrated by simple Python program examples.   The broad scope gives the reader an overview of the state of the art in acoustic metamaterials research and an indication of future directions and applications. It will serve as a solid introduction to the field for advanced students and researchers in physics, applied mathematics and mechanical engineering, and a valuable reference for those working in metamaterials and related areas.