Miriam A. Kolar

On the Acoustics of the Underground Galleries of Ancient Chavín de Huántar, Peru

Chavin de Huantar is a monumental World Heritage archaeological site in the Peruvian highlands predating Inca society by over 2000 years. The importance of site acoustics is suggested by distinctive architectural features, notably an extensive network of underground galleries used in part for ritual purposes. The labyrinthine galleries are arranged in a series of small rectangular alcoves off narrow corridors. Here we focus on measuring and modeling the acoustics at Chavin to understand the implications of auditory experiences within the galleries as related to the sites role in developing religious authority. Acoustic measurements and models of a site can be used to archive site acoustics, estimate the acoustics of inaccessible or alternative site architectures, and reconstruct original site acoustics; they may also be used to corroborate aspects of rituals suggested by other archaeological data. Preliminary acoustic measurements at Chavin show a short reverberation time, dense and energetic early refle...

Pututus, resonance and beats: Acoustic wave interference effects at Ancient Chavín de Huántar, Perú

Acoustic wave interference produces audible effects observed and measured in archaeoacoustic research at the 3,000-year-old Andean Formative site at Chavin de Huantar, Peru. The ceremonial center’s highly-coupled network of labyrinthine interior spaces is riddled with resonances excited by the lower-frequency range of site-excavated conch shell horns. These pututus, when played together in near-unison tones, produce a distinct “beat” effect heard as the result of the amplitude variation that characterizes this linear interaction. Despite the straightforward acoustic explanation for this architecturally enhanced instrumental sound effect, the performative act reveals an intriguing perceptual complication. While playing pututus inside Chavin’s substantially intact stone-and-earthen-mortar buildings, pututu performers have reported an experience of having their instruments’ tones “guided” or “pulled” into tune with the dominant spatial resonances of particular locations. In an ancient ritual context, the recognition and understanding of such a sensory component would relate to a particular worldview beyond the reach of present-day investigators. Despite our temporal distance, an examination of the intertwined acoustic phenomena operative to this architectural–instrumental–experiential puzzle enriches the interdisciplinary research perspective, and substantiates perceptual claims.

A modular computational acoustic model of ancient Chavín de Huántar, Perú.

Inspired by on‐site observations and measurements, a computational acoustic model of the interior architecture of the 3000‐year‐old ceremonial center at Chavin de Huantar, Peru is presented. The model addresses the foundational study by Lumbreras et al. (1976) which posited an acoustic system integral to Chavin architecture involving “a network of resonance rooms connected by sound transmission tubes.” We propose a translation of the topology of Chavin gallery forms to a modular computational acoustic model based on bi‐directional digital waveguides, representing the corridors and ducts, connected through reverberant scattering junctions, representing the small rooms. This approach combines known architectural dimensional and material data with representative measured acoustic data, thus economizing the collection of impulse response measurements required to accurately simulate site acoustics. Applications include virtual acoustic reconstruction of inaccessible or demolished site structures, and auralizations of hypothesized architectural forms, allowing any desired sound sample to be “played back” in the modeled acoustic context.

Sensing sonically at Andean Formative Chavín de Huántar, Perú

ABSTRACT Archaeoacoustics operationalizes non-verbal sound as means and medium for communication. In reconstructing physical, environmental features of ancient places, we infer their consistent sensory reception across the six-digit timeline of Homo sapiens, yet cognition is contextual. How can we reasonably estimate ancient sonic experiences in prehistoric archaeology? Is it possible to infer the significance of sound for past humans who have left no textual traces? Systematic auditory localization experimentation and other archaeoacoustics research within the extant architecture of the Andean Formative ceremonial center at Chavín de Huántar, Perú has demonstrated specific ways in which ancient built acoustics transform humans’ understandings of place and social relations. Transposing principles from information theory to explore the structuring of Chavín’s sonic environment, I argue that sonic symbols that parallel in-situ visual depictions are architecturally encoded at Chavín, constituting multi-channel messaging. For example, the plausible evocation of a roaring cayman through hydraulic-sonic enactment of Chavín’s so-called ‘acoustic canal’ creates a sonic incarnation of that visually depicted crocodilian. Chavín symbols, delivered redundantly and repetitively via multiple, simultaneous sensory channels, would ensure assimilation by ritual participants. If, as evidence suggests, Chavín drew visitors from diverse polities, messaging to a multi-lingual population would necessitate non-linguistic communication, through sensory manipulation in its unique ‘ritualscape’.

Acoustic analysis of the Chavín pututus (Strombus galeatus marine shell trumpets).

In 2001, a group of twenty Strombus galeatus marine shell trumpets were excavated at the 3000‐year‐old ceremonial center at Chavin de Huantar, Peru, marking the first documented contextual discovery of intact sound producing instruments at this Formative Period site in the Andean highlands. These playable shells are decorated, use‐polished, and additionally modified with a V‐shaped cut to the outer apical lip. We present an acoustic analysis of the measured response of each instrument, to a variety of excitations, at microphones placed in the mouthpiece, bore, bell, and surrounding near‐field. From these measurements we characterize each instrument’s sounding frequency, radiation pattern, and impedance, and estimate its bore area function. Knowledge of the specific acoustic capabilities of these pututus allows us to understand and test their potential as sound sources in the ancient Chav\’{i}n context, whose architectural acoustics are simultaneously studied by our research group.

Archaeological auralization as fieldwork methodology: Examples from Andean archaeoacoustics

Auralization, the computational rendering of sound for listeners, enables archaeoacoustical reconstructions. In archaeoacoustics research, computational tools and analyses frequently enmesh with human performance. Broadening the definition of archaeological auralization to encompass the investigative process of specifying and enacting the re-sounding of archaeological spaces, objects, and events positions auralization as a methodology for the sensory exploration of anthropological research questions. A foundational tool for archaeoacoustical and archaeomusicological fieldwork, auralization allows contextualized testing and measurement of spatial and instrumental acoustics, along with their perceptual evaluation. Case-study examples from Andean archaeoacoustics research include auralizations of reconstructed architectural acoustics, and in-situ loudspeaker playback of recorded performances of 3,000-year-old conch shell horns, delivered as auditory perceptual experiment stimuli within the extant ceremonial ...