Diana Deutsch is a British-American psychologist from London, England. She is Professor of Psychology at the University of California, San Diego, and is a prominent researcher on the psychology of music. Deutsch is primarily known for the illusions of music and speech that she discovered. She also studies the cognitive foundation of musical grammars, the ways in which people hold musical pitches in memory, and the ways in which people relate the sounds of music and speech to each other. In addition, she is acclaimed for her work on absolute pitch, or perfect pitch, which she has shown is far more prevalent among speakers of tone language. Deutsch is the author of Musical Illusions and Phantom Words: How Music and Speech Unlock Mysteries of the Brain (2019), the Psychology of Music, and also the compact discs Musical Illusions and Paradoxes (1995) and Phantom Words and Other Curiosities (2003) which have contributed substantially to public interest in the science of sound perception. Her work has achieved considerable recognition by professional organizations, and by the popular media. She has appeared frequently on radio and television, and her discoveries have been described in newspapers and magazines internationally.