Page 30 - Winter2018

Miriam A. Kolar
Address:
Five Colleges, Inc. 97 Spring Street Amherst, Massachusetts 01002 USA
Email:
kolar@culturalacoustics.org
Archaeoacoustics: Re-Sounding Material Culture
Archaeoacoustics probes the dynamical potential of archaeological ma- terials, producing nuanced understandings of sonic communication, and re-sounding silenced places and objects.
Acoustical Experiments in Archaeological Settings
Acoustical First Principles in Practice: Echoes and Transmission Range
Atop a 150-meter-long, 3,000-year-old stone-and-earthen-mortar building, 20 to 40 meters higher than surrounding plazas, two Andean colleagues and I listened to cascading echoes produced via giant conch shell horns known in the Andes as pututus (see Figure 1). Riemann Ramírez, José Cruzado, and I were testing and documenting the performance of an archaeologically appropriate sound source at the UNESCO World Heritage site at Chavín de Huántar, Perú (available at acousticstoday.org/chavin), located at the center of a 400- to 500-meter-wide val- ley 3,180 meters above sea level. Our objective for this experiment, conducted in 2011, was to measure sound transmission via its return from landform features surrounding the site. Although we concurred that we perceived the echoes “swirl- ing around from all directions,” our mission that day was more than reporting subjective impressions. By recording the initial sound and returning echo se- quence using a co-located audio recorder, along with the ambient conditions of temperature and humidity important to calculating the contextual speed of sound in air, I could make precise calculations in postsurvey data analyses regarding the distances of surfaces producing discrete echoes. Via this typical archaeoacousti- cal experiment, we confirmed that the closest rockface on the steep western hill- side, known to locals as “Shallapa,” produced discrete audible echoes with little signal distortion. The test also demonstrated that transmission of the sound of large Strombus pututus, which measure around 96 dB(A) at 1 meter, was effective to at least 1 kilometer away from the site because strong echoes returned 6 seconds later (Kolar et al., 2012, pp. 45-46). This range is consistent with undistorted and audible pututu sound transmission between the site and several archaeologically relevant landform features of the surrounding valley. Pututus such as these were excavated from the 1st millennium BCE architecture at Chavín and continue to be important throughout the Andes today. Therefore, our study not only provided dynamical specifics regarding pututus in the Chavín context but also measures extensible to the archaeology of societies such as the Inca empire that dominated South America 2,000 years later.
Archaeoacoustics: An Archaeological Science
Archaeoacoustics is a developing field that offers the acoustical community an op- portunity to work across disciplines to explore the significance of sound through- out time and across cultures. Archaeoacoustical discoveries often begin with the documentation and mechanical explanation of sound effects or the experimental testing of what can be heard from where. However, archaeology is about putting such findings in human context.
Archaeology spans human time and is about understanding human experience through indirect evidence rather than direct accounts. From excavations of ar-
28 | Acoustics Today | Winter 2018 | volume 14, issue 4 ©2018 Acoustical Society of America. All rights reserved. https://doi.org/10.1121/AT.2018.14.4.30