Sound Studies as a discipline is replete with theories on the relationship between sound and space, and while many point to certain key historical anecdotes to ground far-reaching theories on project-specific examples, few have attempted a historical account of acoustic and auditory spatiality with such specificity and coherence as Gascia Ouzounian. Stereophonica contributes to a growing field of research on this intersection, traversing examples from the nineteenth century to the present day. Using the key concepts of propagation, reflection, and projection, Ouzounian begins with the origins of the ‘binaural listener’. This category of scientific listener explored auditory space through a myriad of technical innovations in stereophonic audition and projection from medical tools such as the stethoscope to military technologies for sound detection.

Stereophonica is roughly divided into two parts: the first examining key intersections between technological innovation and sound theory, and the second surveying a number of artistic practices from mediated broadcast to recent sound art and site-specific installation works, weaving what the author describes as ‘the improbable path from studies of auditory space perception in the nineteenth century to the work of contemporary artists who reveal and reorient urban spaces through sound’ (14). As is necessary for a brief survey with such a wide historical lens, Ouzounian picks key historical episodes that transformed the understanding of sound and space, spanning engineering, warfare, theatre, industry, and urban design. Ending with contemporary uses of this established toolkit of theories, Ouzounian positions the modernist attempt to document, map, plan, and rationalize sound against the social, political, and cultural meanings that the title of the study evokes. As was often the central conflict in modernist rationalization of auditory space, the study and application of sound's effects could never be removed from the discursive social and political understandings of space – one could argue that the modernist attempt to do so in fact created ground for oppositional studies in contemporary practice.

In the first half of Stereophonica, Ouzounian walks us through a cabinet of nineteenth- and early twentieth-century curiosities in sound audition and reproduction, beginning with binaural listening devices such as the differential stethoscope and aural analogues and moving on to the stereoscope such as Anton Steinhauser's Homophone (1879) and Silvanus P. Thompson's Pseudophone (1879), devices that aided in theorizing binaural perception. As amateur and professional scientists soon realized, the ‘binaural listener's’ aural understanding of space was equally important to visual representations in the determination of three-dimensional relief of objects. Experimentations with telephony such as the théátrophone, a system that broadcast live musical performances in stereo, along with other curios such as the Harvard Psychological Laboratory's ‘rotating chair’, helped map out and provide proof of auditory perception as an independent human faculty that informs the holistic and embodied understanding of space in the mind (28–34). Through the enterprising efforts of creative amateurs, binaural listening gradually became a normalized experience and, as the following several chapters observe, proved most useful in military applications of object detection and identification. Having defined and elevated the importance of auditory perception, scientists then quickly sought applications of sound-location technologies and developed a host of training methodologies – some quite painful and debilitating for the individuals subjected to experimentation. During the First World War, British research at the Munition Invention Department's Anti-Aircraft Experimental Section (AAES) and the French l'Etablissement central du matériel de la télégraphie militaire (ECMT) brought forth such inventions as a handheld compass with mirrors for identifying sound directionality, and various acoustic reflectors such as the Baillaud paraboloid, the acoustic goniometer, and the Perrin Telesitemeter that increased in complexity as the war continued, while adding layers of auditory strain on practitioners that set the ground for early health and safety standards for listening technologies. As Ouzounian notes, such experimentation and invention cast sound audition more towards the indexical, where the individual listener functioned more as a sensation device meant to record and translate the military meaning of sounds as perceptible threats with a specific orientation or path to be either avoided or targeted (59–60).

Following the First World War, enterprising individuals and corporations developed this research into commercial applications meant to delight the listener rather than ward off or target impending threats. Ouzounian highlights several examples from the prolific Bell Telephone Laboratories (BTL) research team in New York City. The first popular example was the ‘Oscar Show’, an exhibit during the 1933 Chicago World's Fair consisting of a tailor's mannequin outfitted with microphones installed in each ear. Audiences were outfitted with two telephone receivers while they listened in stereo to a spectacular demonstration of Oscar contained within a soundproof enclosure on stage. At the start of the show the curtains were drawn, and the audience listened to the conversation and sounds of actors on the stage with delight through the transmission of subjective experience of auditory perception in real time. In a similar acousmatic experiment, conductor Leopold Stokowski coordinated with BTL on what became known as the ‘Philadelphia-Washington Demonstration’ at the annual meeting of the Academy of Sciences in 1933. Here an audience of 4,500 scientists and engineers arrived for an evening concert at Constitution Hall in Washington, DC, only to find the curtain rise to reveal a series of loudspeakers broadcasting a live performance by the Philadelphia Orchestra 140 miles away. The audience was stunned by the life-like, three-dimensional quality of the broadcast via a three-channel system with Stokowski at the helm of a mixing board behind the audience, creating the first live mix of acousmatic music that led next to early commercial attempts at releasing ‘enhanced’ stereophonic recordings crafted by one's favorite conductor.

While many of these examples are familiar to those who study the history of sound recording and reproduction technology, Ouzounian nimbly weaves between theory and history, moving next to a chapter devoted to Harold Burris-Meyer's work, first at the Stevens Institute of Technology (SIT) and later as vice president at the Muzak Corporation, on what Ouzounian describes as a kind of musical behaviorism in theatre and commercial music (85). Burris-Meyer presented his first experiments in two ‘Sound Shows’ at SIT in the 1930s that interspersed electronic sounds with incidental music on stage meant to enhance and direct the listening experience and evoke specific emotional responses. Using sounds and music to elicit a behavioral response had both military and commercial application. Burris-Meyer's work with the Muzak corporation attempted to link human biorhythm to assembly-line production that mirrored studies on how sound impacted human psychology from researchers such as Leo L. Beranek at the Electro-Acoustic Laboratory (EAL) and Stanley S. Stevens at the Psycho-Acoustic Laboratory (PAL), both founded at Harvard University in the early 1940s. Training soldiers now involved not just the use of scientific apparatuses for detecting objects via sound, but also making those soldiers the subjects of experimentation in tolerance for wartime noises as a test of endurance using Burris-Meyer's ‘Battle Noise tests’ of recordings of battlefield noises for psychological training. As a counter defense, Burris-Meyer also devised an airborne public address system dubbed ‘Project Polly’ that blasted propaganda from the sky against Japanese soldiers urging them to defect (with little effect). Ouzounian highlights the subliminal effects of these experiments, where sound control and manipulation was blended into the audiovisual montage and veiled as incidental to the individual listener.

The second half of Stereophonica traces this toolkit of concepts through a survey of historical and recent practices in sound art as installation or event that maps or profiles cultural spaces. Ouzounian begins with a genealogy of early sound installation art, highlighting familiar examples such as Edgard Varése's Poème électronique (1958) and Pierre Schaeffer and Pierre Henry's Symphonie pour un homme seul (1949–50) that utilized multichannel loudspeaker systems to project a collage of sound clips and electronic music. Spatiality in terms of the positioning of the individual listener became the new focus of experimental works stemming from Fluxus-inspired activities surrounding John Cage at the end of the 1950s, providing a conceptual bridge between Cagean ideas of indeterminacy between listener and object and the subjective positioning of the active participants in the activity, as a listener, performer, or composer. Ouzounian weaves together a wonderful section that then traces this line of thought from temporal sculpture by 1970s Bay Area artists, such as Tom Marionia and Terry Fox, to sound installation art that encourages one to think of the body as a resonating site for sound through the work of Laurie Anderson and Bernhard Leitner. Evoking philosopher Henri Lefebrve's notion of space as a social construction, Ouzounian then explores participatory works such as communal and localized ‘social sound sculptures’ and sonic walks in the work of contemporary artist Heidi Fast. In contrast with the modernist approaches to using three-dimensional reproduction and recording technology to further define a type of Euclidian mathematical construction of space, post-Cagean experimental practice highlighted the very activity of attempting to define and limit such spaces as a type of social critique that warranted further exploration and experimentation.

On this point Ouzounian points to the work of R. Murray Shafer as the first populist attempt to democratize urban sonic space through the World Soundscape Project (WSP) in the 1970s. By creating subjective ‘noise’ or, in Shafer's terms ‘isobel’ maps, practitioners systematically measured and defined quantitative features of urban spaces while providing a subjective ‘roadmap’ of field notes that resulted in a flurry of cartographic efforts at indexing and defining the depiction of sonic environments on paper. Decibel charts juxtaposed with questionnaire-based noise maps eventually evolved into a series of governmentally sanctioned Noise Exposure Maps (NEMs). These official documents today compete with participatory noise mapping projects using smartphones and applications to crowdsource new models of urban environments that have transformed how communities address urban management, public health, and individual representation in a crowded twenty-first-century landscape. With this interesting survey of aural cartography over the last fifty years, Ouzounian poses many questions about how we conceptualize and understand the acoustic city through art and public policy.

To this point, Ouzounian concludes her study with a personal chapter on sonic urbanism in Beirut, her birthplace and home to some of the most deafening sonic landscapes that epitomize the public planning challenges of the Global South in the twenty-first century. During the Lebanese civil war, it is estimated that upwards of 80 per cent of the city was destroyed, and the post-war rebuilding efforts have resulted in one of the world's most chaotic and noisy urban environments in existence. As has often been the case in massive urban re-architecting programmes in the Global South, public spaces that protected both natural habitat and sonic space were largely overlooked in the push towards redevelopment, and Ouzounian highlights the Civil Campaign to Protect the Dalieh of Raouche, an untamed area on Beirut's coast slated to be quartered off by a luxury hotel, as one example of the conflict between citizens and developers. As part of the intervention campaign, composer and sound designer Nadim Mishlawi recorded the sounds of the coast both above and below the waterline and assembled an installation at the protest titled The Invisible Soundtrack (2017). The mere act of attempting to listen to such a subtle work amid the chaos of protests and noise of the city embodied the conflict that remains at the heart of a city attempting to rebuild itself while preserving a sense of identity. Other works such as Silent Room (2017) by Nathalie Harb commented on the socioeconomic boundaries of sonic noise through the creation of a publicly accessible refuge consisting of a concrete soundproof enclosure planted innocuously at a street intersection of a low-income neighbourhood. Listeners climbed a ladder and removed their shoes to enter a room devoid of the surrounding sonic brutalism only to be accompanied by a just-audible soundtrack of quiet sounds from the city such as generators, air conditioners, and other automatic domestic machines. Following her tripartite division of sonic art examples, Ouzounian compares a performative work from 2014, Concrete Sampling (arrangement for derbekah and jackhammer), by Joe Namy and Ilaria Lupo, where a group of Syrian refugee construction workers improvised a performance using various construction site objects, to 50cm Slab (2018) by Mhamad Safa, which consisted of an electronic concatenation of sounds meant to represent the collapse of a structure during the bombing campaigns of the war projected onto a single space below a slab of metal. Safa's sound sculpture provided a critique of the uneven enforcement of noise policies within Beirut with regard to the horrific effect of thermobaric, or vacuum, bombs that draw the surrounding air to create explosions.

Ouzounian's effort at tracing a specific lineage of listening culture is laudable given the breadth of examples and historical documentation she provides. Her insights into the culture surrounding acoustic space and sound studies reflect a growing trend that represents a cultural theory, historiography, and aesthetics to consider the entire audiovisual experience as fluid, culturally specific, and ever evolving.