This book highlights a comprehensive overview of research and technical advances related to parametric array loudspeakers (PALs), covering modeling and simulation, measurements, signal processing, beamsteering, and their implementations and applications. PALs that can achieve directional sound reproduction have received widespread attention from global researchers due to their advantages of narrow beam, highly directivity, and very small sidelobes. PALs have developed rapidly in theory and application and have been used in various commercial products. At present, PALs have become a research hotspot in the field of audio engineering. The book is a must-have guiding reference for researchers, professionals and graduate students who seek to conduct further research on PALs.