This somewhat elusive term has evolved since the late 1950s, and attempts to define it have provoked much-heated debate amongst academics and practitioners. The term has a specific meaning in audio engineering (see 2 below), and a rather-too-simplistic explanation is that it was adopted as an inclusive and umbrella term as the activities of musique concrète, tape music, and electronic music composers saw almost immediate cross-fertilization, which continued through the 1960s and 70s.
The term saw early usage in the United Kingdom and Canada, and during the 1970s tended (amongst other terms) to be used in the French language (électroacoustique) in place of musique concrète. The term was never in wide usage in the United States, where Electronic Music, Tape Music and Computer Music predominated, but recent years have seen an increased usage here too. The term is currently widely used in several European/South American languages, including Spanish and Portuguese.
More recently, some, particularly in Canada, have adopted the term Electroacoustics, which includes Electroacoustic Music Studies in its sense, and has the advantage of emphasising the interdisciplinary nature of the field in the nuance of its meaning. (See 4 below)
Some argue that the term is so elusive as to be unhelpful, and should therefore be abandoned. Others opt for the most general possible use of the word as an umbrella term (see 1 below). The English language has seen increased recent usage of the terms Sonic Art and Electroacoustics in place of Electroacoustic Music. The French language has several nuanced alternatives, including l’Art de Sons Fixés (Michel Chion) and Musique Acousmatique (proposed by François Bayle in the early 1970s as a replacement for Musique Concrète, and a means of delineating his aesthetic concerns within the broader field of Electroacoustic Music).
In an attempt to illustrate nuance, the following four established definitions are offered below.
1. Electroacoustic music refers to any music in which electricity has had some involvement in sound registration and/or production other than that of simple microphone recording or amplification. (Source - Leigh Landy (1999). Reviewing the Musicology of Electroacoustic Music. Organised Sound Vol. 4, No. 1. Cambridge: Cambridge University Press: 61-70)
2. An adjective describing any process involving the transfer of a signal from acoustic to electrical form, or vice versa. Most commonly transducers, such as the microphone or loudspeaker are examples of this process.
Although the term most precisely refers to a signal transfer from electrical to acoustic form or vice versa, it also is often used more loosely to refer to any process for the electronic generation and/or manipulation of sound signals, including techniques of sound synthesis for the electronic or digital generation of such signals. When the purpose of such manipulation is artistic, the result is commonly called electroacoustic music. (Source: Barry Truax - Handbook for Acoustic Ecology CD-ROM Edition. Cambridge Street Publishing, 1999 - CSR-CDR 9901)
3. Music in which electronic technology, now primarily computer-based, is used to access, generate, explore and configure sound materials, and in which loudspeakers are the prime medium of transmission. There are two main genres. Acousmatic music is intended for loudspeaker listening and exists only in recorded tape form (tape, compact disk, computer storage). In live electronic music the technology is used to generate, transform or trigger sounds (or a combination of these) in the act of performance; this may include generating sound with voices and traditional instruments, electroacoustic instruments, or other devices and controls linked to computer-based systems. Both genres depend on loudspeaker transmission, and an electroacoustic work can combine acousmatic and live elements. (Source - Simon Emmerson, Denis Smalley (2001). The New Grove Dictionary of Music and Musicians - Second Edition. Ed. Stanley Sadie.)
4. (Electroacoustics) The use of electricity for the conception, ideation, creation, storage, production, interpretation, distribution, reproduction, perception, cognition, visualization, analysis, comprehension and/or conceptualization of sound.
(Source - Kevin Austin, with an acknowledgement to Michael Century)
UNESCO DigiArts- Music using technology ( English , French )