Soundscape Ecology

Dr. Bryan PijanowskiDepartment of Forestry & Natural Resources

“Over increasingly large areas of the United States, spring now comes unheralded by the return of the birds, and

the early mornings are strangely silent where once they were filled with the beauty of bird song.”

Rachel Carson – The Silent Spring 1962

Overview

1. What is a soundscape?2. Play example soundscapes (5-8 recordings)3. Describe how we measure soundscapes4. Summarize some of our research surrounding

Purdue University5. Describe the role of engineers in research like

this

1. WHAT IS A SOUNDSCAPE?

Biophony – sounds created by biological organisms, mostly insects, amphibians, birds and mammals. Signals carry information and are thus complex.

Geophony – sounds from the movement of wind and water. Driven mostly by climate. Running streams, rain and wind.

Anthrophony – sounds by human-made objects such as machines, friction from road noise, bells, sirens.

Soundscapes

Definitions of Soundscapes• R. Murray Schafer (1994): “the soundscape is

any acoustic field of study… We can isolate an acoustic environment as a field of study just as we can study the characteristics of a given landscape. However, it is less easy to formulate an exact impression of a soundscape than of a landscape” (p. 7).

• Bernie Krause (1987, 2002): all of the sounds (biophony, geophony and anthrophony) present in an environment at a given time, soundscape as a finite resource-competing for spectral space (acoustic niche hypothesis).

What it is not

• Bioacoustics: traditionally focused on species specific traits or a single group of organisms –this is a 70 year old field of study

• Noise research: examining how noise is created in human-dominated areas

2. SOUNDSCAPE EXAMPLES

Wildlife Area, West of Campus, Midnight, Spring 2009 (Pijanowski)

Madagascar, Dawn Chorus (Krause)

Congo, Nighttime (Krause)

Purdue Evening, Urban Soundscape (Pijanowski)

“Tiny” Soundscape (Krause)

3. HOW WE MEASURE SOUNDSCAPES

Computerized acoustic sensors that are set to record 15 mins at the start of every hour

Illustration of a complex dawn chorus (Madagascar)

Freq

uenc

y

Time (30 secs total)

4. RESEARCH SURROUNDING PURDUE

Acoustic Sensor Locations and Land Use

Pijanowski et al, in press. Bioscience.

(c) Land Use/Cover within 100m

(c) Land Use/Cover within 1kmpe

rcen

t

(a) Length of Roads (by type, in meters) within 1km of recorder

Gini Coefficient definition

Measures evenness across equal sized categories

Uses area under Lorentz curve (ordered cumulative distributions)

Gini coefficient values

= 1 (all sounds are from one frequency band)

=0 (all sounds are equally distributed across all frequency bands)

Measure of Acoustic Frequency Evenness

Step 1 – Import WAV file to GIS

Step 2 – Threshold map based on dB

Step 3 – Filter binary map using majority

Step 4 – Convert to shape file and calculate geometry (area)

Step 5 – Histogram of area (for one 15 recording)

1 10 100 1,000AREA

0.00.00.00.0

Proportion per Bar

1

10

100

1,000

10,000

Cou

nt

Sound Patch Analysis

Spectrograph as a Unit of Analysis

freq

uenc

yfr

eque

ncy

freq

uenc

yfr

eque

ncy

Time (15 mins) Time (15 mins)

Purdue Wildlife (Wetland) Area, April 7, 2008

Rhythms of Nature

Hour

Acou

stic

Fre

quen

cy D

iver

sity

Dawn ChorusDusk Chorus

Peak and troughDifferential Amax-Amin= 0.23

Trough

Peak

Frequency Band Entropy Averaged By Hour and Site

5. LA SELVA WORK

40m20m

2mover

over river

2m from edge

20m from river edge

40m from river edge

Waveforms and Spectrograms for 10 sec recordings at La Selva (near SOR350)

Design Database Management Systems (this one stores over 20 TB of data!)

http://1159sequoia05.fnr.purdue.edu/tippecanoe/

http://1159sequoia05.fnr.purdue.edu/laselva/

Special issue in Landscape Ecology(October 2011 issue)

Truax and Barrett. Foreword to the special issuePijanowski and Farina. Introduction to the special issuePijanowski et al. What is soundscape ecology?Barber et al. Modeling noise in National ParksFrancis et al. Nesting success of birds in noisy environmentsElda et al. National Park Service soundscape management plansDumyahn and Pijanowski. Managing soundscapes as common pool resourcesDumyahn and Pijanowski. Soundscape conservationVillanueva-Rivera et al. A primer of acoustics for ecologists

Global Sustainable Soundscape Network

Research Coordination Network52 founding members (North America, Europe and Australia)

ecologistspsychoacousticiansenvironmental engineersmusicians part of acoustic ecology

Activitiesvisit 8 ecosystems (Alaska, desert, Borneo, Tuscanny, northern lakes, jungle)share datadevelop standards

Theme Teamsrecording standardsanalysis and toolsdata managementpolicy and managementengage the public

http://www.davidmonacchi.it/indiceen.htm

David Monacchi – Italian Soundscape Composer (Artist and Sound Engineer)

Ambisonic instrumentation

Design a better acoustic sensor

Need sensors that can (1) withstand harsh environments (2) record a long time with the need for artificial power (3) transmit acoustic data via wireless communication (4) set up in sensor networks (1000s of acoustic sensors synchronized) (5) integrate other sensors (temperature, precipitation, humidity, wind speed, wind direction, soil moisture, surface albedo)

Light Detection And Ranging (LiDAR)

• Active remote sensing• Range (Laser) + Location

(GPS) + Attitude (IMU) = 3D coordinates of surface

Collect and Process Remote Sensing Data to Characterize Landscapes

2006 LIDAR Data Acquisition

Dr. P in Costa Rica (Oct. 2010)

For further informationDr. Bryan Pijanowski305 FORS BuildingDepartment of Forestry and Natural Resourcesbpijanow@purdue.edu

• Acknowledgements–Discovery Park Center for the Environment

and the Department of Forestry and Natural Resources for funding

–College of Agriculture and Department of Forestry and Natural Resources

–Stuart Gage and Bernie Krause–Melba Crawford, Jinha Jung and Luis

Villanueva-Rivera