The voice of the natural world

Bernie Krause has been recording wild soundscapes -- the wind in the trees, the chirping of birds, the subtle sounds of insect larvae -- for 45 years. In that time, he has seen many environments radically altered by humans, sometimes even by practices thought to be environmentally safe. A surprising look at what we can learn through nature's symphonies, from the grunting of a sea anemone to the sad calls of a beaver in mourning.

(Nature sounds)

When I first began
recording wild soundscapes

45 years ago,

I had no idea that ants,

insect larvae, sea anemones and viruses

created a sound signature.

But they do.

And so does every wild
habitat on the planet,

like the Amazon rainforest
you're hearing behind me.

In fact, temperate
and tropical rainforests

each produce a vibrant animal orchestra,

that instantaneous
and organized expression

of insects, reptiles,
amphibians, birds and mammals.

And every soundscape
that springs from a wild habitat

generates its own unique signature,

one that contains incredible
amounts of information,

and it's some of that information
I want to share with you today.

The soundscape is made
up of three basic sources.

The first is the geophony,

or the nonbiological sounds that occur

in any given habitat,

like wind in the trees, water in a stream,

waves at the ocean shore,
movement of the Earth.

The second of these is the biophony.

The biophony is all of the sound

that's generated by organisms
in a given habitat

at one time and in one place.

And the third is all of the sound
that we humans generate

that's called anthrophony.

Some of it is controlled,
like music or theater,

but most of it is chaotic and incoherent,

which some of us refer to as noise.

There was a time when
I considered wild soundscapes

to be a worthless artifact.

They were just there,
but they had no significance.

Well, I was wrong. What
I learned from these encounters

was that careful listening gives
us incredibly valuable tools

by which to evaluate
the health of a habitat

across the entire spectrum of life.

When I began recording in the late '60s,

the typical methods
of recording were limited

to the fragmented capture
of individual species

like birds mostly, in the beginning,

but later animals
like mammals and amphibians.

To me, this was a little like trying
to understand

the magnificence
of Beethoven's Fifth Symphony

by abstracting the sound
of a single violin player

out of the context of the orchestra

and hearing just that one part.

Fortunately, more and more institutions

are implementing the more holistic models

that I and a few of my colleagues
have introduced

to the field of soundscape ecology.

When I began recording
over four decades ago,

I could record for 10 hours

and capture one hour of usable material,

good enough for an album
or a film soundtrack

or a museum installation.

Now, because of global warming,

resource extraction,

and human noise, among many other factors,

it can take up to 1,000 hours or more

to capture the same thing.

Fully 50 percent of my archive

comes from habitats so radically altered

that they're either altogether silent

or can no longer be heard
in any of their original form.

The usual methods of evaluating a habitat

have been done by visually
counting the numbers of species

and the numbers of individuals
within each species in a given area.

However, by comparing
data that ties together

both density and diversity
from what we hear,

I'm able to arrive at much
more precise fitness outcomes.

And I want to show you some examples

that typify the possibilities unlocked

by diving into this universe.

This is Lincoln Meadow.

Lincoln
Meadow's a three-and-a-half-hour drive

east of San Francisco
in the Sierra Nevada Mountains,

at about 2,000 meters altitude,

and I've been recording
there for many years.

In 1988, a logging company
convinced local residents

that there would be absolutely
no environmental impact

from a new method they were trying

called "selective logging,"

taking out a tree here and there

rather than clear-cutting a whole area.

With permission granted to record

both before and after the operation,

I set up my gear and captured
a large number of dawn choruses

to very strict protocol
and calibrated recordings,

because I wanted a really good baseline.

This is an example of a spectrogram.

A spectrogram is a graphic
illustration of sound

with time from left
to right across the page --

15 seconds in this case is represented —

and frequency from the bottom
of the page to the top,

lowest to highest.

And you can see
that the signature of a stream

is represented here in the bottom
third or half of the page,

while birds that were once in that meadow

are represented in the signature
across the top.

There were a lot of them.

And here's Lincoln Meadow
before selective logging.

(Nature sounds)

Well, a year later I returned,

and using the same protocols

and recording under the same conditions,

I recorded a number of examples

of the same dawn choruses,

and now this is what we've got.

This is after selective logging.

You can see that the stream
is still represented

in the bottom third of the page,

but notice what's missing
in the top two thirds.

(Nature sounds)

Coming up is the sound of a woodpecker.

Well, I've returned
to Lincoln Meadow 15 times

in the last 25 years,

and I can tell you that the biophony,

the density and diversity
of that biophony,

has not yet returned
to anything like it was

before the operation.

But here's a picture
of Lincoln Meadow taken after,

and you can see
that from the perspective of the camera

or the human eye,

hardly a stick or a tree
appears to be out of place,

which would confirm the logging
company's contention

that there's nothing
of environmental impact.

However, our ears tell us
a very different story.

Young students are always asking me

what these animals are saying,

and really I've got no idea.

But I can tell you that they do
express themselves.

Whether or not we understand
it is a different story.

I was walking along the shore in Alaska,

and I came across this tide pool

filled with a colony of sea anemones,

these wonderful eating machines,

relatives of coral and jellyfish.

And curious to see
if any of them made any noise,

I dropped a hydrophone,

an underwater microphone
covered in rubber,

down the mouth part,

and immediately the critter began

to absorb the microphone into its belly,

and the tentacles were
searching out of the surface

for something of nutritional value.

The static-like sounds that are very low,

that you're going to hear right now.

(Static sounds)

Yeah, but watch. When it
didn't find anything to eat --

(Honking sound)

(Laughter)

I think that's an expression
that can be understood

in any language.

(Laughter)

At the end of its breeding cycle,

the Great Basin Spadefoot toad

digs itself down about a meter under

the hard-panned desert
soil of the American West,

where it can stay for many seasons

until conditions are just
right for it to emerge again.

And when there's enough moisture
in the soil

in the spring, frogs will dig
themselves to the surface

and gather around these
large, vernal pools

in great numbers.

And they vocalize in a chorus

that's absolutely in sync
with one another.

And they do that for two reasons.

The first is competitive,
because they're looking for mates,

and the second is cooperative,

because if they're
all vocalizing in sync together,

it makes it really difficult
for predators like coyotes,

foxes and owls to single
out any individual for a meal.

This is a spectrogram
of what the frog chorusing looks like

when it's in a very healthy pattern.

(Frogs croaking)

Mono Lake is just to the east
of Yosemite National Park

in California,

and it's a favorite
habitat of these toads,

and it's also favored by U.S.
Navy jet pilots,

who train in their fighters
flying them at speeds

exceeding 1,100 kilometers an hour

and altitudes only a couple hundred meters

above ground level of the Mono Basin,

very fast, very low, and so loud

that the anthrophony, the human noise,

even though it's six and a half kilometers

from the frog pond you
just heard a second ago,

it masked the sound
of the chorusing toads.

You can see in this spectrogram
that all of the energy

that was once in the first
spectrogram is gone

from the top end of the spectrogram,

and that there's breaks
in the chorusing at two and a half,

four and a half,
and six and a half seconds,

and then the sound
of the jet, the signature,

is in yellow at the very
bottom of the page.

(Frogs croaking)

Now at the end of that flyby,

it took the frogs fully 45 minutes

to regain their chorusing synchronicity,

during which time, and under a full moon,

we watched as two coyotes
and a great horned owl

came in to pick
off a few of their numbers.

The good news is that, with a little bit
of habitat restoration

and fewer flights, the frog populations,

once diminishing
during the 1980s and early '90s,

have pretty much returned to normal.

I want to end with a story
told by a beaver.

It's a very sad story,

but it really illustrates how animals

can sometimes show emotion,

a very controversial subject
among some older biologists.

A colleague of mine was recording
in the American Midwest

around this pond that had been formed

maybe 16,000 years ago at the end
of the last ice age.

It was also formed in part by a beaver dam

at one end that held
that whole ecosystem together

in a very delicate balance.

And one afternoon, while he was recording,

there suddenly appeared
from out of nowhere

a couple of game wardens,

who for no apparent reason,

walked over to the beaver dam,

dropped a stick of dynamite
down it, blowing it up,

killing the female and her young babies.

Horrified, my colleagues remained behind

to gather his thoughts

and to record whatever he could
the rest of the afternoon,

and that evening, he captured
a remarkable event:

the lone surviving male beaver
swimming in slow circles

crying out inconsolably for its
lost mate and offspring.

This is probably the saddest sound

I've ever heard coming from any organism,

human or other.

(Beaver crying)

Yeah. Well.

There are many facets to soundscapes,

among them the ways in which animals
taught us to dance and sing,

which I'll save for another time.

But you have heard how biophonies

help clarify our understanding
of the natural world.

You've heard the impact
of resource extraction,

human noise and habitat destruction.

And where environmental
sciences have typically

tried to understand
the world from what we see,

a much fuller understanding
can be got from what we hear.

Biophonies and geophonies
are the signature voices

of the natural world,

and as we hear them,

we're endowed with a sense of place,

the true story of the world we live in.

In a matter of seconds,

a soundscape reveals much more information

from many perspectives,

from quantifiable data
to cultural inspiration.

Visual capture implicitly frames

a limited frontal perspective
of a given spatial context,

while soundscapes widen that scope

to a full 360 degrees,
completely enveloping us.

And while a picture may
be worth 1,000 words,

a soundscape is worth 1,000 pictures.

And our ears tell us

that the whisper
of every leaf and creature

speaks to the natural
sources of our lives,

which indeed may hold the secrets
of love for all things,

especially our own humanity,

and the last word goes
to a jaguar from the Amazon.

(Growling)

Thank you for listening.

(Applause)