abstracts (alphabetically by first author’s last name) 

Jonathan S. Abel and Wieslaw WoszczykOn synthesizing room impulse response copies at and away from measurement locations 

Room impulse responses often exhibit a spatial bloom, being focused about the source during the impulse response onset, and enveloping the listener as the room mixes and its response decays.  In addition, as the source and listener move about a space, the character of the room impulse response changes with different room modes being driven and observed.    These effects may be simulated in an auralization system by panning sound sources among convolutions with statistically independent room impulse responses associated with different listener arrival directions.  In this work, we consider the problem of synthesizing such statistically independent impulse responses, and describe methods for producing perceptual "copies" of a given measured impulse response, and for estimating impulse responses at locations away from those measured. The methods flow from the idea that the perception of a room impulse response may be characterized by its normalized echo density profile and its response energy profile in a set of frequency bands.  In particular, to create a statistically independent copy of a room impulse response, a set of echo times and amplitudes is randomly generated according to the measured normalized echo density profile, and then processed to reproduce the measured band response energy profiles.  To synthesize an impulse response away from those measured, the same process is used, with the generating normalized echo density profile and response energy profiles formed by interpolating those measured.  In an example, a set of statistically independent copies of an impulse response measured at Stanford's Memorial Church are synthesized, and found to be perceptually similar to and effectively uncorrelated with each other.  In another example, a set of impulse response measurements made in the church nave along a line between two endpoints were found to be perceptually similar to ones synthesized using only the endpoint measurements.

Julio BermudezNeurophenomenology & Sacred Architecture. First Steps
Since time immemorial, sacred buildings have operated as pedagogic instruments offering religious information and environments that facilitate the experience of spiritual reality. Beauty has been invariably recruited as builders of holy places almost universally figured that aesthetically pleasing experiences open minds and hearts. Disciplines such as theological aesthetics and material anthropology have provided explanations for such practices and successes but since their arguments are not based on hard empirical evidence, they have no scientific standing at the time of elucidating how religious architectures actually accomplish such feat. This project seeks to address this lack of understanding by deploying neuroscience to investigate architecture’s aesthetic power to elicit spiritual cognitive responses. To date, neuroscientific research of ‘spiritual’ states has mainly focused on self-regulated (i.e., internally initiated, subjective) experiences whereas the very few investigations of the effect of sensory stimulation in enabling such states (e.g., iconography) have largely ignored architecture. We address this void by studying brain and physiological correlates of internal states elicited by religious architecture. Ambulatory EEG and bio-sensors are employed to measure the differential responses of 30+ individuals of faith experiencing two aesthetic situations (one religious: the Basilica of the Immaculate Conception, and one secular: Union Station – both in Washington DC) along with their first-person phenomenological reactions. This presentation will share the theoretical, methodological, and technical framework supporting this interdisciplinary effort as well as offer an in-progress report of the insights being gained.

Braxton Boren : Contextualization in Worship Space Acoustics

Though the physics of reverberant sound fields in enclosed spaces is (as best we can tell) universal and independent of human cultural interpretation, the specific numerical parameters used in acoustical analysis are not. The field of quantitative architectural acoustics as we know it arose within the particular culture of late 19th-century New England, one which was highly influenced by mainline Protestantism and Modernism. As a result, some of its fundamental assumptions – the intelligibility of the spoken word or the instrumental ensemble used during a worship service – were also shaped by the worldview of that culture. Other religious traditions, however, may hold different fundamental values or worldviews within which these assumptions are less appropriate. Some examples include acoustic differences between Catholic and Protestant churches, low-church a cappella denominations, Hindu temples, and online worship “spaces.” It is argued that each of these faith’s values may require not only different application of the same “universal” acoustic parameters, but in many cases new contextualized parameters may be necessary to understand the sound field within each tradition’s understanding of itself.

Eoin Callery:  Virtual Acoustics - Thoughts on Late 20th and Early 21st Century Ears 

Through the use of real-time virtual acoustic systems, the reverberant conditions of any performance or rehearsal space have the potential to be altered. When using these systems, the audience and performers have the sense that they are hearing sounds in a space other than the actual or expected acoustic of the physical space they occupy. Virtual acoustic systems employing loudspeakers (rather than headphones) have the potential to provide audiences and performers with a full sense of acoustic agency within virtual audio environments - any sound made within the virtual environment, intentional or not, will be reverberated by the virtual environment as it would be in a real space. While this has profound implications for many disciplines, including all disciplines that intersect with the performing arts, how we become aware of and use this acoustic agency raises some very interesting questions and considerations about the nature of virtual acoustic technologies. In particular, these new technologies have perhaps only emerged due to quality of our 20th and 21st Century ears - and not just because of our technological abilities. How might this be influencing and illuminating, or even obscuring and distorting, the research projects that can now utilize virtual acoustic technologies?

Zühre Sü GülThe dome effect and the acoustics of historical masterpieces

The dome as a pure geometrical form, generated by the rotation of an arch around a central vertical axis, shelters a semispherical volume beneath. This is the most sophisticated, yet simple way of spanning the largest area, without any obstruction, and with minimum material use. Since its primitive origins as a hut in Neolithic times, the dome element has gone through progressive changes. The structural stability with the evolving use of core materials enabled larger domes to be constructed in Roman, Byzantine and Ottoman eras. This archetypal form has symbolized the celestial sphere and has become the universal expression of heaven in certain religions. The dome has signified unity and congregation in mosques, which have a more compact plan in comparison to churches.
The reflections from the dome are frequently accused for causing particular acoustical effects or defects such as echo, flutter echo etc. depending upon the its size, height from the ground and the position of the sources and the receivers on the floor surface. Some architectural elements, such as clay pots (Sebu) applied by Sinan in his mosques and tombs, embedded within the dome and facing out to the interior space with an opening are considered to provide acoustical diffusion helping to cure sound foci, while increasing the low frequency absorption. On the other hand, some recent studies highlighted that the dome geometry coupled to a prismatic base, and multiples of them connected to each other can cause multiple-slope sound energy decay formation.   Such an architectural configuration is mostly observed in historical and monumental sacred structures.
In this study, the sound field of multiple sound energy decays indicating multiple reverberation times, are discussed regarding two sites; Hagia Sophia (6th century) and Süleymaniye Mosque (16th century). Both structures are multi-volume spaces with many smaller sub-volumes coupled to each other by coupling apertures in form of arches. The methodology of investigation for coupling effects starts with the acoustical field tests carried in different times within the two structures. The analysis of real data indicated multi-slope energy decays in certain positions in both structures. In order to further understand the mechanism behind, energy flow decays are examined by applying diffusion equation model (DEM) in a finite-element scheme for sound energy flow analysis. Energy flow decays, energy flow dips, and spatial flow vectors are compared also for different states of the monuments that have gone through various renovations, material alterations and even functional changes in time.   In order to support DEM findings, ray-tracing simulations are also utilized, the data of which are subjected to Bayesian analysis to identify the decay parameters and the degree of acoustical coupling. Among the many variables, the dome form, material distribution, the source-receiver distance and positioning within different sub-spaces appear to be the underlying determinant of multi-slope sound decay pattern. Lastly, multi-slope sound energy decays are discussed in light of acoustical needs and spiritual expectations from such monumental sacred spaces.

Elliot Kermit Canfield-Dafilou: Reconstructing the acoustics of Notre Dame

Notre-Dame, the emblematic Gothic cathedral of Paris is one of the most recognizable cultural heritage sites in the city. In 2019, a fire broke out in the cathedral’s attics that destroyed the spire and much of the roof, left large holes in the vaulted ceiling, and threatened the structural integrity of the building. Although the French government has vowed to rebuild the cathedral in its “last known visual state” before the fire, the cathedral has changed significantly throughout its storied history. In this presentation, I will talk about ongoing interdisciplinary work related to studying the acoustics and intangible cultural heritage of Notre-Dame de Paris as part of the JPI CH project PHE and ANR project PHEND. In particular, I will focus on the first 300 years of the cathedral, discussing the simultaneous construction of the edifice (and resulting changes in room acoustics) and the development of a polyphonic music tradition through the use of room acoustics measurement and simulation. Following this, I will present vignettes of other Notre-Dame acoustics research related to the historic placement of the children’s choir and the realistic simulation of the grand organ of Notre-Dame.

David Kirsh:
Humans enter physical environments (built and natural) with all our senses active. Cross modal illusions occur when one sensory interpretation contradicts another. We see one thing but we hear another. These illusions occur because sometimes when our brains try to render a consistent and meaningful interpretation of all perceptual input they create experiences that are incorrect. These illusions - incoherencies - teach us about cognition and have potential value for the design of Architecture and the Metaverse. I briefly discuss a few inconsistencies that can arise between what we hear and what we see and some implications for design.

Miriam Kolar : Sounding the Scale of Humans: Proxemics and Acoustical Space in Archaeological Research
Proxemics, contextualized understandings of distance relationships, are fundamental to human social interactions. Archaeology, the study of human life from its material remains,  documents and reconstructs physical features of places and objects in order to infer their use potentials. Contextualized archaeological knowledge — what I call "archaeological possibility space" — offers clues to past experiences and events whose sonic communication substrate can be estimated and virtually simulated. My "human-centered" archaeoacoustics research puts into conversation knowledge from psychoacoustics and perceptual psychology with performance studies to explore the human-environmental relationships, interaction affordances, and action potentialities expressed in archaeological materials. Human-sonic interactivity defines human-spatial relationships in specific ways, providing perceptual cues that influence humans' sense of scale and proxemical understandings within an environment. Here, I share case-study examples from fifteen years of Andean archaeoacoustics and music archaeology research, and I report on new collaborative research about human-sonic interactions in Paleolithic decorated caves.

Licia Mari:  Music and ceremonies in the sacred space of the palatine basilica of S. Barbara in Mantua
The palatine basilica of S. Barbara is located within the architectonic complex of the Ducal Palace. Built between 1562 and 1572, it was designed by the architect Giovan Battista Bertani (one of Giulio Romano’s apprentices), who followed personally the construction and the styling of the interiors, ensuring everything went accordingly to duke Guglielmo’s project, according to which architecture, painting, music, liturgy and sacred furnishings are closely linked in a unitary vision. A famous organ builder from Brescia, Graziadio Antegnati, was hired to craft the precious church organ. During church services, the organ was employed in polyphonic works, probably performed with only a few singers and, eventually, instruments such as cornets and trombones. The church offered various possibilities for musical performances: the choir, located in the apse, was used for plainsong chanted by the clerics; opposite to the organ, lies a similar gallery used by soloists and instrumentalists; another larger gallery was placed above the entrance of the church and there a group of singers was positioned to perform a tailored polyphonic vocal repertoire.
The basilica was not conceived as a place for few, illustrious guests, but as a tangible sign of the relationship between the duke and his entire community, who participated enthusiastically to important feasts, such as that of Santa Barbara, on the 4th of December.
The paper intends to present and examine XVI-XVII century ceremonies, looking at how the spaces were managed and what kind of music was performed, taking advantage of the features of the church.

Stella Nair (UCLA) and Jonathan Ritter (UC Riverside) :Voicing Inca History: Gender, Space. and Music Education in Imperial Schools.
In this paper, an architectural historian (Stella Nair) and an ethnomusicologist (Jonathan Ritter) explore the intricate relationship between Inca spaces and musical performances, particularly the role of song in elite musical education. The authors explore the ways in which the Inca created and modified the built environment in order to best suit their dynamic acoustical events, especially in the training and performance of boys and girls.  Drawing from a diversity of sources, including colonial text and images, Inca architectural remains, and ethnographic studies of Andean vocal performance past and present, the authors explore how the Inca used sounds, especially vocal genres, in their imperial theatrics and the ways in which architectural spaces, interior and exterior, were designed to amplify and celebrate these novice sonic events. 

Cobi Van Tonder: Acoustic Atlas – Cultivating the Capacity to Listen

The Acoustic Atlas project explores a new model for experiencing acoustic heritage data in the form of room impulse responses (RIRs), as real-time auralisations. The browser-based Web Audio application utilises the built-in microphone and headphone output of the device to transport the user to a selected heritage site via headphones and a live microphone feed. Users are able to send their voice into archived heritage sites and experience a sonic glimpse of the reverberation, reflections and resonances of a selected site. Fundamental to the project is the growing community of researchers that are sharing their work via submitting the acoustic fingerprints of their individual research projects.
In the light of 'urgency of climate change', Donna Haraway responded with the creation of the terms 'sym-poiesis' - a making together as well as 'response-ability' which is a 'cultivation through which we render each other capable, that cultivation of the capacity to respond'.  The aim of Acoustic Atlas is to render us capable, to listen. We take action (respond) through active listening - rendering each other capable to listen. The project is a sym-poiesis of virtual acoustic map making, contemplating what the sound of each space mirrors in our imaginations. The cultivation of the capacity-to-listen-to and connect beyond time and space. Connected to this topic are more general aspects of open access of scientific data. By sharing research in interactive audible formats, the audience and reach of these projects vastly increase. Accessibility is expanded, no specialist knowledge is required to hear acoustic fingerprints.
In parallel, Acoustic Atlas explores sound and space compositionally through properties of resonance and reverb as well as by looking into origin myths and histories connected to voice, space, ritual and art.
The application can be experienced at

Timothy Weaver: Ecoacoustics of Gathering

The surface and geometric qualities of natural space provide ground for acoustically-driven ecological interactions.  This presentation will compare a range of western hemisphere ecological soundscapes and the influence of ecoacoustic factors on territoriality and the gathering of species. These factors will then be re-mapped onto select open-air, anciently inhabited Southwestern (US) heritage sites as points of dialogue for contrasting eco- and human sound spaces.

Tobias Weissmann: On the Interrelation of Sacred Architecture and Music in Pre-Modern Italy

In medieval and early modern Italy, the religious practice and the perception of the divine have been determined by the intersection of sacred space, rite and music. With their form and specific acoustics, church buildings influenced the musical compositions and the performance practice. Vice verse, architecture reacted to ritual and compositional developments by modifying venerable sanctuaries or designing and constructing new buildings. The most distinctive                                                                      impact of this progress is epitomised by the installation of separate singer balconies in the course of the 16th and 17th century to serve the polychoral musical performance practice. The permanent display of music advanced to become a core element of sacred architecture while the potential of these spaces to promote identification becomes evident in numerous graffiti.

Based on selected case studies such as the Cappella Palatina in Palermo, the Sistine Chapel in the Vatican and San Luigi dei Francesi in Rome, this paper will present the work of the research project “CANTORIA – Music and Sacred Architecture” (Johannes Gutenberg University Mainz), which explores the interdependencies between architecture, musical performance practice and liturgy in the interdisciplinary discourse between musicology, art and architecture history. 

Wieslaw Woszczyk and Jonathan S. Abel: Room impulse response estimation from recordings: Recovering the impulse response of Columbia Records' 30th Street Studio from a documentary recording of Glenn Gould in the studio

Room impulse responses are typically measured using high-quality broadband loudspeaker sources and an array of microphone receivers able to register directional properties of ambient sound within an existing physical structure. A recording of a long exponential sinusoidal sweep signal is deconvolved to render a room impulse response with a high dynamic range. A gun shot or balloon pop can instead deliver an acoustic impulse to initiate the room response, and the recording requires post processing to improve spectral, temporal, and dynamic characteristics needed to form an impulse response for auralization.
For a physical structure that no longer exists, or exists only virtually as a model, impulse responses can be synthesized based on spatial/geometrical characteristics and boundary surface conditions assumed in the model (e.g. via Odeon or CATT). The accuracy of numerical descriptions of acoustic phenomena are being steadily improved while computer processing speed and better perceptual validation make rendering of modelled spaces attractive.
This work reports on early results in room impulse response estimation achieved using acoustic signals embedded in recordings made in historical venues as these still existed, in this case, the famed Columbia Records' 30th Street Studio in NYC. To facilitate the RIR estimation, ambient impulsive sounds recorded during the filming of Glenn Gould recording sessions in 1959 were isolated to provide source/receiver signals for analyses. The larger question is: can we recreate for a performer today the acoustic space Glenn Gould encountered in that studio in 1959?
The process involves first estimating the echo density and frequency band energies in running windows over the room response following an impulsive sound (footstep, click, door slam), then synthesizing a pattern of full bandwidth echoes matching the measured echo density profile, and finally imprinting the measured band energy profiles. This method is based on the approach used by Abel, et al., to reconstruct an impulse response of Hagia Sophia by recording a single balloon pop.
By generating statistically independent echo patterns, multiple mutually decorrelated impulse responses can be created which perceptually mimick the reference response derived from the recording. Such impulse responses can be used in auralization via low-latency convolutions once their dynamic range, frequency spectrum, and temporal profile are sufficiently corrected towards an idealized short duration impulse. The challenges encountered in this estimation will be described and the aural result will be presented.