A paper in progress. By Jason Diceman © 1999
This paper analyzes the characteristics of audio, the traditional use of audio communication, and the new potential of electronic audio.
Characteristics of Audio
Audio is the human interpretation of sound. Sound is waves of energy that cause disturbances in a medium (Rowe 1997)
The following is a point list of some of the important characteristics of sound.
This simple definition of audio provides us with the frame work which we must work within when conceptualizing audio content. We realize that to navigate audio we must control a device which changes the current linear content being output. We know that because sound waves combine and can be reflected, the environment in which audio is listen to will affect what is heard. We also learn that although any sound can be created, it must be meaningful to a listener to serve any useful function. The elements of meaningful audio can be organized in to four categories:
Music – a collection of sounds structured by a system and composed in to patterns. Communicates artistic messages.
Language – an established set of sounds that have specific meanings and functions. The foundation of a system of communication. Communicates information potentially using artistic techniques.
Noise – sounds that are neither language nor musical. Can communicate anything but music and language. This includes environments, physical actions, ambiguous emotions, …etc.
Silence – a sound vacuum. Only of value in relation to sound. An amount of time devoid of sound.
Although music, language and noise are all very broad terms that cover a vast amount of sounds, language, which has the most potential for specific information exchange, has a history of being confined by traditional formats.
Traditional Audio Dialogue
The informational format presents content in a factual, news-like style. This is frequently used in instructional presentations which guide a student through a specific process. Sentences are purposefully direct and are void of superfluous color and texture.
The personal narrative strives to involve listener participation. This style is conversational, frequently acknowledges the presence of the listener, and directs attention to specific concepts or ideas.
The third style makes use of a dramatic or poetic presentation. Such narrative employs descriptive adjectives, use of analogies, imaginative rhythms, and other compositional elements which strive for maximum sensory response. (Thompson, 1969).
Although these categories are helpful for describing traditional script writing, it must be understood that dialogue does not have to be confined to any one category. Dialogue is the use of multiple words, and so as infinite there are words and word arrangements and verbal styles, so there is limitless ways of creating dialogue. Knowing this we can conceptualize and create new forms of dialogue specific to the nature of different mediums and the needs of the message. But before we can create new models of audio communication, let us understand the traditional audio models.
Traditional Audio Models
Broadcast Audio has been defined as a one way linear transmission. That is to say that the listener can not affect the content and the reception occurs at the same instance and in the same structure as the broadcast. Listeners can not rewind or pause, or switch tracks or ask a question. Broadcast is usually used to transmit mass content to a large audience.
Examples: Radio and Public Address Systems
Audio with Visual is a dual medium format. Both audio and visuals can exist on their own, but when content is written and produced to use audio and video together, then they become interdependent. Movie dialogue requires visuals to put the conversations in to context. Movie visuals need audio to enhance emotional impact and to communicate the content of verbal elements.
Examples: Movies, TV Content, Video Games
Recorded Audio is independent of time. The content can be stored, retrieved and presented out of sequence. Users can repeat, pause, play, rewind and skip portions of the content. Recorded Audio is mostly used for music and some spoken word.
Examples: Digital Discs, Vinyl Records, Magnetic Tape
Two-Way Audio means that a receiver is also a transmitter. A listener can have impact on the content of the medium by communicating directly with the contents creator. It is mostly used for live, one-to-one conversations.
Examples: Telephone, Intercom and Walkie-talkie
Musical instruments must be played to be heard. They can not record content nor can they transmit dialog. They are used for artistic purposes and are often combined to create works that are greater than the sum of their parts. A listener can also be at the same time a player and thus a content creator.
Examples: Electronic Guitar, Organ and Synthesizer
It should be obvious that not every form of electronic audio production fits cleanly in to one of these categories. There are many hybrid audio application formats that have characteristics from different models. (Examples: Telephone answering machine, sampling MIDI keyboard, broadcast recordings.) These five categories are more for historical analysis then conceptual application
With all this in mind, we now have an understanding of what audio is and what content and application models have been used. For our purposes of understanding the potential of audio communication, we are interested in the ability of audio to go beyond the simple models of live broadcasting and linear storage. We need to research complex possibilities such as dynamic automated audio production, content transferring mediums and interactive audio application. These features can be achieved by encoding sound waves in to electronic information, which then has the complex possibilities of electronic data. We must remove ourselves from the confines of traditional models, understand the characteristics and potential of audio that is encoded and physically reproduced using electrical devices, the effects of using different techniques and what form of content best suites the characteristics of each technique.
Characteristics of Electronic Audio Media
Alteration:
All audio that is electronically encoded is altered from the original. The degree of change is limitless. There are different causes inherent in each medium. Change may also be purposefully done by a sound designer.
Examples: Tape hiss, vinyl "pops", audio compression artifacts, the limiting of detail from the original physical sound waves.
Source:
Synthetic – A wave form is generated without reference to any natural occurring sound. Example: A tone generator.
Physical – A real sound is encoded in to electronic information. Example: Microphone recording.
Dynamic Range:
Limits of transmission intensity. Examples: Telephone communication can not be as loud as a home stereo system.
Bandwidth (Frequency Range):
Levels of possible pitch reproduction. Examples: A single midrange speaker can not reproduce the same high and low pitches that a three way speaker can.
Spatial Referencing:
Relative dimensions of perceived sound origins. Examples: A single speaker produces audio in one dimension. Two speakers can produce audio in two dimensions (stereo) or three dimensions (Binaural).
Encoding:
The different techniques for encoding come in two main categories: digital and analogue. Although neither is officially superior in quality, the inherent ability of loss less duplication and transfer, and the flexibility and accuracy of computer manipulation has made digital the modern choice.
Example: A Compact Disc uses digital encoding. A compact cassette uses analog encoding.
Compression:
The different encoding techniques allow for the same amount of audio information to use less space. This means that more audio, or greater audio detail can be stored in a record medium and transferred faster. The amount of compression is measured in a ratio in relation to the size of the uncompressed electronic version. Every compression technique changes the audio to some degree. Examples: Early compressed "internet radio" required very little digital information but was barley distinguishable. Modern DolbyÒ compression uses a moderate compression ratio to achieve high-fidelity sound.
By understanding the limits and potential of different electronic audio media, one can choose the most appropriate medium for the goal of a communication. Examples: The more detail and range (realism) a medium can reproduce, the more emotional impact it can potentially produce. Highly compressed audio is easier to mass distribute. Music requires more range than speech.
Electronic audio applications can be very complex when encoding digitally and then processed by computers.
Computer Audio
Computers can manipulate, generate, and record digital electronic audio.
They also have the ability to do complex instructions dependant on user input variables. This means that an audio computer medium can provide complex interactive features. The ability for a computer to generate speech from text and music from notation means that almost any features associated to text and vector art can now be applied to audio. The infinite variety of interfaces that are available to communicate with computers allows for infinite ways of interacting with and navigating audio content. Digital audio can be easily transferred great distances and to masses of people via the many kinds of digital networking systems, quickly and without losing quality. For these reasons computer based audio has the most potential for mass, personalized, in-depth, educational and entertaining audio content.
Examples of Possible Features
Hyperlinked Audio Dialogue: an audio cue, such as a tone or verbal announcement, notifies listeners when there is an option to switch to other related content.
Personalized Recorded Audio: The computer uses personal variables in a program to create original and alter recorded audio specifically for a users needs.
Navigation by Content Elements: Users can jump from idea to idea rather than fast forward and rewind through time.
Verbal Dialogue Interaction: The user input is speech recognition and the computer output is speech synthesis. The effect is conversation like human-computer interaction.
Conclusion
The potential of computer based audio content is only limited by our technical know how, and imagination. Now is the time to break free of the old models of audio content and research the potential for more effective communication. With our understanding of cognitive learning and listening process we can use computer based mass audio communication to teach millions of people important ideas, skills and knowledge. We can provide listeners with a variety of entertaining and provocative forms of content that may open their minds and provoke thought and emotion. It is our responsibility as citizens who understand the applied technology, academic theory and artistic design of modern communication to push it to its fullest potential. Communication is the essence of society. The misuse and restriction of communication potential for private gains is the selfish act of delaying human progress.
References:
Ferrington, Gary. (1993) Audio Design: Creating Multi-Sensory Images For The Mind. Journal of Visual Literacy. Ohio: Ohio State University
http://interact.uoregon.edu/MediaLit/FC/readings/sndesign.html
Lee, Dana M. (1998) Television Technical Theory: Unplugged
McLuhan, Marchall (1964) Understanding Media. MIT Press
Rowe, Lawrence A.( 1997) Audio Fundamentals
http://www.BMRC.Berkeley.EDU/~larry
Thompson, James. (1969) Instructional Communication. New York: Van Nostrand Reinhold Company.