Chavin

Chavín de Huántar Archaeological Acoustics Project

Acoustic Measurement, Archiving, Analysis and Modeling, and Simulation/Installation

Team Information

Co-investigators:

• John Rick, PhD, Professor, Stanford University, Archaeology/Anthropology
• Julius O. Smith, PhD, Professor, Stanford University, Center for Computer Research in Music and Acoustics (CCRMA)/Electrical Engineering (by courtesy)
• Jonathan S. Abel, PhD, Consulting Professor, Stanford University, CCRMA
• Patty Huang, MA, Graduate Student, Stanford University, CCRMA
• Miriam Kolar, MFA, Graduate Student, Stanford University, CCRMA

Coordinator:

• John Chowning, DMA, Professor Emeritus, Stanford University, CCRMA/Music

Local collaborators:

• (Museum director)

Team Background:

• John Rick has been heading excavations and directing research at the Chavín site since 1995
• Digital waveguide techniques were pioneered at CCRMA by Julius O. Smith III
• Julius O. Smith and Jonathan S. Abel have been working together on acoustic array processing and related problems since 1985
• Patty Huang is a 4th year graduate student working under Abel on physical modeling of reverberant spaces
• Miriam Kolar is a 2nd year graduate student with extensive field experience in recording engineering
• John Chowning is a composer having long standing interest in spatial modeling
• CCRMA has expertise in field measurements, psychoacoustics, digital signal processing, and artificial reverberation

Phase 1. Preparation and on-site measurements

Preparation

• Preliminary on-site tests [completed 12/07]
• Specification of test and recording equipment [completed 1/08]
• Purchase and assemble gear

Simulation Trials in local environments

• CCRMA stairwell, hallways, “Pit”
• SU subsurface spaces-“famous” steam tunnels
• Outdoor space similar to Chavín Circular Plaza?

Specify provisional mapping for sound source-receiver placements from CAD rendering [in progress 1/08]  

• from each chamber to main space
• least damaged areas
• with and without plastering
• peculiar geometries (e.g. , adjoining (comb-like) chambers, etc)

On site measurements at Chavín

• Plastering of section of Chavín (selection of plastered sections is critical (soon after arrival to allow for drying)
• Adjust mapping of source-receiver points

Measurements -- impulse response

• balloon pops
• speaker-generated sinusoidal chirps
• other signals
• strombus trumpet live/recorded
• record stream/water sound, wind noise

Measurements -- receivers

• distributed mics
• in-ear-canal mics

Costs

• $5000 equipment (link to gear and price list)
• $8000 travel and accommodations (2 weeks on site) for 2 faculty (Rick, Abel), 2 graduates students (Huang, Kolar)
• $1000 on site plastering and removal

Funding

• National Geographic [1]
• SU internal

Phase 2. Analysis and Generation of Physical Model

Analysis

• compare plastered and unplastered and extrapolate to the entire structure
• IR measurement to render the modeled spaces
• measurement processing to model the pristine state
• Strombus trumpet

Physical Model

• calculate acoustical properties of materials
• rendering from architectural models
• use waveguide mesh processing
• Stanford invention of and current work with waveguide mesh allows effective method to address computation/simulation of acoustical spaces
• process and match/fit measurements then extend to parts of site that aren't necessarily intact or accessible for comprehensive measurements (plastering).

Costs

Funding Sources

• National Geographic [2]
• National Endowment for the Humanities- Collaborative Research Grants [3]

Phase 3. Electroacoustic simulation & Public interface

Locations

• Stanford
• Chavín Museum
• Quantify and compensate for support structures
• Simulation of plastered walls
• National Museum Peru

Equipment

Public interface

• virtual walkthrough (headphone tour) in present condition
• virtual walkthrough (headphone tour) in reconstructed condition
• enhanced reverberation system for visitor experience
• installations of replica in various formats (online, DVD, museum, show, etc.)