基调声音/Ji1 Diao4 Sheng1 Yin1
In soundscape studies, keynote sounds are those which are heard by a particular society continuously or frequently enough to form a background against which other sounds are perceived. Examples might be the sound of the sea for a maritime community or the sound of the internal combustion engine or hums in the modern city. Often keynote sounds are not consciously perceived, but they act as conditioning agents in the perception of other sound signals. They have accordingly been likened to the ground in the figure-ground relationship of visual perception.
(Source : Barry Truax - Handbook for Acoustic Ecology CD-ROM Edition. Cambridge Street Publishing, 1999 - CSR-CDR 9901)
What Are They?
Keynote sounds are central to the soundscapes that we hear. They are so significant that we hear all other sounds in relation to them.
We can think of Keynote sounds as significant objects against a background.
We don’t always hear Keynote sounds consciously, but they define the character of the soundscape.
They are created by where we are (geography and climate), what time it is (day/night, past/present) and by what is going on (sounds of farm animals / sounds of traffic).
The idea of Keynote sounds is taken from music and so works in a similar way to how different musical key signatures affect the sound of a piece of music.
A piece of music played on a piano in the key of C major, will sound different to a piece of music played on the same piano in the musical key of B minor.
Both pieces contain piano notes, but the Key defines the character of the piece.
This is exactly the same for Keynote sounds. Different keynote sounds define the character of a location in different ways.
Wind, water, forests, birds, insects and animals
Every location has a different natural environment, with different creatures living in it and these different creatures create different sounds.
Keynote Soundclip One
This keynote sound can tell us something about where it was recorded
Keynote Soundclip Two
This was recorded in a very different location.
Keynote Soundclip Three
Does this sound come from the same location as either clip one or two? Or does it come from somewhere new? How can you tell?
Each of these example clips sound very different and the sounds we hear tell us about what is going on.
Keynote sounds are the ones that tell us most about where we are.
Think about the sounds you hear at home. Are there any Keynote Sounds that help you to recognise when you are at home.
What about when you are at school? Can you identify the Keynote Sounds that come with school?
How are these different from the Keynote sounds you hear at home?
[TIP: Perhaps making a list will help you to compare, and closing your eyes will help you to focus only on the sounds].
Place, Location, Climate
North, South, East, West – sounds change as we travel around the world. Even as we travel through one town or city, different neighbourhoods can sound very different.
Different climate zones will sound very different from one another. The sounds of the arctic or antarctic (think snowy ice sheets, polar versa and penguins) will be very different to the sounds of the tropics (rainforest, parrots, and buzzing insect sounds).
Because of this we can use recordings of keynote sounds in our composing with sounds to make people think that they are listening to sounds in different locations.
Postcards From Summer (Excerpt)
Listen to this clip. Can you hear how the shifting keynote sounds transport you on a journey between a series of different iconic locations?
Sounds of the Past
Keynote sounds also change over time. Yes, they may be different in the daytime or at nighttime, but they can undergo real change through the years.
Imagine the development of a city:
A long time ago, at the very beginning, there was no city just a field or forest.
Then humans moved in and built huts to live in. Gradually, over time, more people came and built houses. What was once open fields began to fill up with more and more houses.
Then industry came and the factories clattered and banged.
Slowly, the nature of the industry changed, moving from heavy industry to high tech computers and components. The factories ceased to clatter and bang and instead clicked and beeped.
Can you identify the keynote sounds in this story? How would they change over time?
[TIP: Again, you may find it useful to make notes for each step. Compare your notes with someone else and discuss]
By manipulating or introducing Keynote sounds and Sound Marks we can change peoples perception of what they think they are listening to: where they think it is, when they think it is happening, what is going on.
This can be a very powerful tool in constructing imaginary soundscapes.
When we watch these films and television programmes we hear the sounds and they help us to believe that the characters and plots are actually taking place in outer space (when they are really happening in a Film studio).
In this scenario the Sound Designer has composed the soundscape, introducing Keynote sounds and sound marks which tell us about the supposed location.
Activity – So Where Do the Sounds Come From?
Sound Designers will use the following process to find the sounds that they need.
1. Try to make a list of the sounds that you might expect to hear.
2. Close your eyes and imagine these sounds on their own.
3. Think of the characteristics of these sounds. What do they sound like?
4. Try to think of any similar sounds that you might come across every day.
Once we have some idea of what types of sounds we need, we can go out and try to find them.
Sometimes we can’t find the sound directly, BUT we can find a sound which can then be transformed into the sound that we need.
This process can be repeated for any imaginary soundscape.
Composition Example: Spaceship Sounds
Imagine the sounds of a spaceship.
Very few people have actually been on a spaceship, but may of us have some idea of what a spaceship might sound like. This is because Sound Designers working in film and television have taken everyday sounds and edited them together to create these pretend soundscapes.
Spaceships often might be expected to contain the beeping or clicking sounds of technology or machinery,
The whirring or droning sounds of the environment on board and the zap of a laser gun.
All of these sounds have to be abstracted from the world around us and edited together.
Beeping sounds can be found around us in modern technology, but often we want spaceship sounds to seem futuristic. This may mean that we need to create beeping sounds from simple sine tones, or at least transform recordings that we make with reverberation and delay.
Beepif recorded on a metro train
Transformed Spaceship Sound
Beeping computers and throbbing high-tech power source. This sound was made using transposition and delay.
Whirring environment sound
The atmosphere of the spaceship is very important. We need to impart the impression of whirring technology and a closed environment. We can find similar sounds in schools and office buildings with air conditioning units, though we may need to transform these sounds.
Transformed - Spaceship Sound
Spaceship ambience. This sound was made using transposition and filtering.
By transposing and filtering the sound of an extractor fan we can create the impression of a low background rumble of spaceship engines.
No space ship is complete without a laser gun.
As we discovered (in Sounds Around Us) we can use everyday objects to make fantastical sounds. Laser gun sounds can be recorded from a metal slinky.
Laser Gun Sound
This sound was made by inserting a paper cup into the top of a metal slinky and tapping the slinky onto the floor.
Many ordinary objects can be used to make extraordinary sounds. The art of performing sounds to create sound effects is called Foley. You can find out more about the work of Foley Artists here.
They form a background for other sounds and define a certain location, place or time.
Examples might be the sound of the sea (when you’re near the coast) or the sound of traffic in the modern city.
Keynote sounds are so common that they are often not heard. But they are always there and will influence the way in which we hear other sounds.
Keynote sounds are usually created by nature (geography and climate): wind, water, forests, birds, insects, animals. But can also be man made, for example: traffic has become the keynote sound in many cities.
术语顾问/Consultant to terminology