Designing Sound for Animation

Robin S. Beauchamp

• Editore: CRC Press
• Anno: 2013
• ISBN:
  9781136143816
• Edizione: 2
• Argomento: Ciencia de la computación
• Categoria: Programación de juegos

Sound is just as crucial an aspect to your animation as your visuals. Whether you're looking to create a score, ambient noise, dialog, or a complete soundtrack, you'll need sound for your piece. This nuts-and-bolts guide to sound design for animation will explain to you the theory and workings behind sound for image, and provide an overview of the stems and production path to help you create your soundtrack. Follow the sound design process along animated shorts and learn how to use the tools and techniques of the trade. Enhance your piece and learn how to design sound for animation.

Chapter 1

Foundations of Audio for Image

Overview

The concepts presented in this chapter are intended to develop conceptual common ground and a working vocabulary that facilitates communication between the filmmaker, sound designer, and composer. Where possible, these concepts are presented in the context of the narrative film.

Perception of Sound

Sound

There are three basic requirements for sound to exist in the physical world. First, there must be a sound source, such as a gunshot, which generates acoustic energy. The acoustic energy must then be transmitted through a medium such as air. Finally, a receiver, such as a listener’s ears, must perceive and interpret this acoustic energy as sound. In Film, the animator creates the first two conditions, the sound designer represents these conditions with sound, and the audience processes the sound to derive meaning. Sound can also be experienced as a part of our thoughts, in a psychological process known as audiation. As you are silently reading this book, the words are sounding in your head. Just as animators visualize their creations, composers and sound designers conceptualize elements of the soundtrack through the process of audiation. Voice over (in the first person) allows us to hear the interior thoughts of a character, an example of scripted audiation.

Audio without image is called radio, video without audio is called surveillance.

Anonymous

Hearing Versus Listening

When acoustic energy arrives at our ears, it excites the hearing apparatus and causes a physiological sensation, interpreted by the brain as sound. This physiological process is called hearing. However, if we are to derive meaning from sound, we must first perceive and respond to the sound through active listening. Audiences can actively listen to a limited number of sounds present in the soundtrack. Fortunately, they can also filter extraneous sounds while focusing on selected sounds; this phenomenon is known as the cocktail effect. One shared goal of sound design and mixing is to focus the audience’s attention on specific sounds critical to the narrative.

To listen is an effort, and just to hear is no merit. A duck hears also.

Igor Stravinsky

Localization

In most theaters (and an increasing number of homes), sound extends beyond the screen to include the sides and back of the room. The physical space implied by this speaker configuration is referred to as the sound field. Our ability to perceive specific sound placements within this field is known as localization (Figure 1.1).

Figure 1.1 The Soundtrack in the Sound Field

The panners (pan pots) on a mixing board facilitate the movement of sound from left to right by adjusting the relative levels presented in each speaker. Using this approach, individual sounds can be placed (panned) within the sound field to accurately match on-screen visuals even as they move. Off-screen action can be implied by panning sound to the far left or right in the stereo field (Figure 1.2).

Figure 1.2 Volume Panning

Independent film submission requirements typically call for a stereo mix but there is an increasing acceptance of multi-channel mixes. Multi-channel sound extends the sound field behind the audience (surrounds). The surrounds have been used primarily to deliver ambient sounds but this role is expanding with the popularity of stereoscopic (3D) films. Walt Disney pioneered multi-channel mixing with the Fanta-sound presentations of “Fantasia” in the late 1930s, adding height perspective for the sixtieth anniversary screening.

Acoustics

Acoustics is a term associated with the characteristics of sound interacting in a given space. Film mixers apply reverb and delay to the soundtrack to establish and reinforce the space implied onscreen. The controls or parameters of these processors can be used to establish the size and physical properties of a space as well as relative distances between objects. One of the most basic presets on a reverb plug-in is the reverb type or room (Figure 1.3).

Figure 1.3 Reverb Room Presets

The terms dry and wet are subjective terms denoting direct and reflected sound. Re-recording mixers frequently adjust the reverb settings to support transitions from environment to environment.

Rhythm and Tempo

Rhythm is the identifiable pattern of sound and silence. The speed of these patterns is referred to as the tempo. Tempo can remain constant to provide continuity, or accelerate/decelerate to match the visual timings of on-screen images. Footsteps, clocks, and heartbeats are all examples of sound objects that typically have recognizable rhythm and tempo. Vehicles, weapons, and dialogue are often varied in this respect. Many sounds such as footsteps or individual lines of dialogue derive additional meaning from the rhythm and tempo of their delivery. This is an important point to consider when editing sound to picture. Composers often seek to identify the rhythm or pacing of a scene when developing the rhythmic character of their cues.

Noise and Silence

The aesthetic definition of noise includes any unwanted sound found in the soundtrack. Noise always exists to some degree and sound editors and mixers have many tools and techniques to minimize noise. Backgrounds are sometimes mistakenly referred to as noise. However, backgrounds are carefully constructed to add depth to a scene whereas noise is carefully managed as not to detract from the narrative. Silence is perhaps the least understood component of sound design. Silence can be an effective means of creating tension, release, or contrast. However, complete silence is unnatural and can pull the audience out of the narrative. Silence before an explosion creates contrast, effectively making the explosion perceptually louder.

It’s the space between the notes that give them meaning.

Nathan East

The Physics of Sound

Sound Waves

The sine wave is the most basic component of sound. The horizontal line shown in Figure 1.4 represents the null or zero point, the point at which no energy exists. The space above the line represents high pressure (compression) that pushes inward on our hearing mechanisms. The higher the wave ascends, the greater the sound pressure, the more volume we perceive. The highest point in the excursion above the line is the peak. The space below the line represents low pressure (rarefaction). As the wave descends, a vacuum is created which pulls outward on our hearing mechanism. The lowest point in the downward excursion is the trough. A single, 360° excursion of a wave (over time) is a cycle.

Figure 1.4 The Sound Wave

Frequency

Frequency, determined by counting the number of cycles per second, is expressed in units called hertz (Hz); one cycle per second is equivalent to 1 hertz (Figure 1.5).

Figure 1.5 Six Cycles Per Second

Pitch is our subjective interpretation of frequency such as the tuning note for an orchestra being A=440 Hertz. The frequency range for humans begins on average at 20 Hz and extends upwards of 20,000 Hz (20 kHz). Frequency response refers to the range of fundamental frequencies that an object can produce. Frequency response is a critical factor in the selection of microphones, recording devices, headphones, speakers, and commercial SFX/Music. It is also an important qualitative feature relating to audio compression codecs such as Mp3 and AAC. In musical terms, the frequency range of human hearing is 10 octaves, eight of which are present in a grand pi...