What is a soundscape?

How should soundscapes be

quantified and characterized?

Christine ErbeJASCO Applied SciencesAustralia, Canada, USA, UK

Overview

1. The Marine

Soundscape

a) Ambient (physical)

Sounds

b) Biological Sounds

c) Anthropogenic Sounds

2. Quantification &

Characterisation

Soundscape:

• an acoustic environment consisting of natural

sounds (including animal vocalizations and the

sounds of weather) and anthropogenic sounds

Acoustic Ecology:

• the study of the relationship—mediated

through sound—between organisms and their

environment

1. Marine Soundscape > Definitions

Natural

Ambient

Sound

[Wenz 1962, JASA 34(12): 1936-1956]

Frequency [Hz]

Spe

ctru

m D

ensi

ty L

evel

[dB

re

1 µ

Pa2

/Hz]

1. Marine Soundscape > a. Natural Ambient Sound

Rain

Fre

quen

cy [H

z]

Time [min:sec]

1. Marine Soundscape > a. Natural Ambient Sound

Ice Noise• Due to deformation, fracturing, breaking & collision of ice

sheets & floes, caused by wind, currents, waves, melting & freezing, internal & surface stresses

• Broadband: Hz – 10s of kHz• Quietest during stable or warming conditions with low winds• Loudest during periods of rapid cooling or strong winds

Correlate noise spectrum with environmental parameters [Greene & Buck 1979; Oard1987; Yang et al. 1987; Wen et al. 1989, 1990; Xie & Farmer 1991, 1992; Feller 1994; Greening & Zakarauskas 1994; Uscinski & Wadhams 1999; Stein et al. 2000 etc.]1. Marine Soundscape > a. Natural Ambient Sound

1. Marine Soundscape > a. Natural Ambient Sound

1b. Biological Sounds

• Marine Mammals

1. Marine Soundscape > b. Biological Sounds

Ocean water conducts light very poorly but

sound very well.

⇒ Marine mammals rely primarily on their

acoustic sense for

• Social interaction

• Communication

• Navigation

• Foraging

1. Marine Soundscape > b. Biological Sounds

Odontocete Sounds• generated within the nasal system, not the larynx

• can be classified into 3 categories: tonal whistles, burst-pulse

sounds and echolocation clicks

• echolocation used for navigation & foraging

• Ǝ geographic differences in call characteristics of the same

species

• Dialects (sound differences between populations sharing the

same geographic region) have been identified for killer whales

and sperm whales.

http://staff.more.net/denise/whales/lesson1.htm

1. Marine Soundscape > b. Biological Sounds

Killer Whales

Time [min:sec]

Fre

quen

cy [

Hz]

1. Marine Soundscape > b. Biological Sounds

Ford 1991, Can J Zool 69: 1454-1483

1. Marine Soundscape > b. Biological Sounds

1. Marine Soundscape > b. Biological Sounds

http://orcasound.net/

Beluga Whales

1. Marine Soundscape > b. Biological Sounds

Fre

quen

cy [H

z]

Time [min:sec]

1. Marine Soundscape > b. Biological Sounds

Humpback Song & Sonar[Patrick Miller]

Fish

Haddock

Cusk-eel

Toadfish

[http://www.fishecology.org/soniferous/justsounds.htm]

1. Marine Soundscape > b. Biological Sounds

Tropical Ambient

(fish & crustaceans)

1. Marine Soundscape > b. Biological Sounds

1c. Types and Characteristics of

Anthropogenic Noise

1. Marine Soundscape > c. Anthropogenic Sounds

Airguns

1. Marine Soundscape > c. Anthropogenic Sounds

Pile Driving

[Erbe 2009]

1. Marine Soundscape > c. Anthropogenic Sounds

Fre

quen

cy [

Hz]

Large Vessels

Propeller Cavitation Noise

[Erbe & Farmer 1998, 2000]

1. Marine Soundscape > c. Anthropogenic Sounds

Pleasure

Craft

1. Marine Soundscape > c. Anthropogenic SoundsF

requ

ency

[H

z]

How do we measure

soundscapes?

=> after the coffee break…

2. Quantification:

Ambient Noise Percentiles

2. Quantifying the Marine Soundscape

Night-time chorus of snapping shrimp

Humpback whales

Distant seismic survey

Fish

Tidal flow

Spectrograms

2. Quantifying the Marine Soundscape

2. Quantifying the Marine Soundscape

Sandpump

17%

Boats

19%

Humpbacks

17%

F3 pinger

14%

F10 pinger

14%

Snapping

shrimp

19%

Total Energy [dB] / Day

The problem with these pie charts…

Same data as in slide 24:

2. Quantifying the Marine Soundscape

Sandpump

4%

Boats

35%

Humpbacks

2%

F3 pinger

0%

F10 pinger

0%

Snapping

shrimp

59%

Linear Energy / 24hSame data:

2. Quantifying the Marine Soundscape

Sandpump

5%

Boats

73%

Humpbacks

1%

F3 pinger

0%

F10 pinger

0%

Snapping

shrimp

21%

Linear PowerSame data:

2. Quantifying the Marine Soundscape

Sandpump

0%

Boats

36%

Humpbacks

0%F3 pinger

29%

F10 pinger

0%

Snapping

shrimp

35%

1/3 Oct SPL @ 6kHzSame data:

30

40

50

60

70

80

90

100

10 100 1000 10000

Bilogical noiseWind dependent noiseTraffic noise

Winddependentnoise

CA 60s

CA 90s

Shrimps

Shrimpsinshore

chorusesEveningchorus

Fish

5 kn

10 kn

20 kn

30 kn

RD

IO

TS

FREQUENCY (Hz)

NO

ISE

SP

EC

TR

UM

LE

VE

L (d

B r

e 1

µPa2 /H

z)

2. Quantifying the Marine Soundscape

(Doug Cato)

• Modelling Soundscapes => later today

• Noise Effects on Animals => tomorrow

http://AquaticAcousticArchive.com

Thank You !Thank You !Thank You !Thank You !