|
|
 |
 |
 | | | | |
 |
|||
 |
||||||
          |
 |
 |
||||
|
The Art of Noise: Game Studio Recording and Foley
No matter how heated the ensuing battle in the back of your mind, the game is ruined. It feels fake, not on par with what you expected. Even the weapons seem wimpy, meaning the combat must be unbalanced to give the enemies the edge. Of course that must mean the game design isn't really that solid. And without good game design the latest release from Design Team X lasts only a few days on the hard drive and a lifetime collecting dust on the shelf. On the increasingly level playing fields of 3D acceleration, elaborate input devices, and broadband capability, game companies are working harder than ever to find ways to differentiate themselves from one another. While design and art play a major role in this process, sound is also an important factor in a game's success or failure. In fact, it's increasingly rare to find top-selling titles that don't also feature top-notch audio design. So if you're having trouble making your game's sound environment bigger and more distinguishable from your competition's, this article is designed to help. Sound designers have myriad tools and techniques at their disposal to create a complete audio environment for their game. Sound effects libraries are often the easiest starting point for a design job and are available in dozens of flavors, from big production houses down to small, one-man shops. In general, stock sounds are available on individual CDs or in complete sets with a common theme. Some of the more progressive sound providers offer download capability from their web sites, allowing you to grab samples even while pulling an all-nighter. In general, prices for sound CDs and libraries match the quality of the material on them. Cheaper libraries will tend to be just straight (sometimes monophonic) recordings of the source material. Noise and background leakage may even be present. Nicer libraries will be clean recordings, occasionally even enhanced a little, and feature good indexing, allowing you to find what you need quickly. The best libraries will have been pieced together by professional sound designers. Sound generation from an electronic source, such as a synthesizer or a software package, is another route to take. Sound designers working off of traditional white or pink noise functions, which provide an even noise distribution over a frequency range or octave values, have often found it the most flexible way to sculpt a complex sound. Because synths provide a clean source from which to work, recording issues are also not a concern. Often, intermixing or triggering a completely artificial sound with studio or field recorded samples can produce convincing results. Field recording is somewhat similar to studio recording, except that in many cases you will not be in direct control of the source material, but will rather be working around it. Field recording can be especially useful for recording large scenes and ambient waveforms. In many cases just having a portable DAT and microphone will do, but sometimes a more elaborate setup is needed. Other issues to consider when field recording are sometimes less obvious. For example, at a military base, the recording of some equipment may not be allowed without permission. Other places may have restrictions regarding free movement or the kinds of recordings you can make. Even worse, some environments may have electrical equipment that will interfere with your gear's recording capability. While not a replacement for other sound design techniques, in-studio recording of sound effects (called Foley) saves both time and money spent searching for the right material elsewhere. For cutscenes or streamed audio clips, Foley can be entirely comprehensive and extremely fast. Additionally, material can be created that is perfectly matched to your production, not shoehorned in from an audio CD. Even today, it is not uncommon to hear some of the same tired sound effects reused in game after game and in commercial after commercial. The determined walk-step of your gun-toting hero can be cast a certain way, while the sneaky footsteps of the villain he is about to fight can be cast in another. Most game designers would cringe if they thought the same piece of game art from the competition was being reused in their game. Why should sound be any different? Finally, Foley techniques provide an excellent excuse to junk up the development studio with all kinds of fun, eclectic props (see sidebar, "Foley Props"). This article is intended for sound designers who are looking to go beyond the "sound via CD" techniques commonly overused in game production. The focus is on studio recording within typical game development budgets. Experienced sound designers already working in upscale studios may also find this article a good refresher. Setup Although in-studio recording is a fairly involved process, setting up correctly before a session can be timesaving. In fact, a lot of things ought to be done before the first audio take occurs. There are no hard and fast rules for budgeting sound design, other than to make sure you do actually budget for it. Too often on small projects it's listed as something the sound programmer or the music guy can do on the side, or in some cases it's forgotten altogether. It is also good to tackle sound development early enough in the project to make sure it nears completion long before the headaches of trying to master happen. Using an outside contractor for your audio development is recommended if you can't do the work appropriately in-house. Bringing them on the project early will also yield fewer hassles and better results, as there will be more time to make everything perfect. The specific time requirements for sound effects development will vary from designer to designer and project to project. Variables such as how complex the sound requirements are, the sophistication of the audio equipment being used, and how much pre-existing library material is already on hand also enter the equation. For a typical game development situation, a good rule of thumb is to budget about half an hour per incidental effect (minor or background-type material) and a full hour for major elements (foreground and repeated sounds). Foley work can expedite this process, particularly for minor effects. Budgeting equipment is another issue to consider. Starting from scratch, you can expect to put together a simple game-capable recording studio for both vocals and effects for under $5,000. Adding high-end, feature-film-quality equipment or a multi-channel digital recording system can run you quite a bit more. If your sound budget is tight, consider renting sound equipment rather than purchasing it. Items such as microphones, mixers, and DATs typically rent for nominal rates and will often be cheaper on weekends. When planning an in-house recording session, creating a comprehensive sound list or an audio storyboard for the game is a good starting point. Generally, these kinds of lists are based on unit tables or level descriptions and should be broken out by sound type. Keep in mind, sound lists are just as useful for finding out what you don't need to create as they are for what you do. From the sound list, it isn't difficult to break sound groups into rough production categories of how each waveform will be built. Foleys are generally best for "personal" sounds attached to characters and creatures, or specialty effects that require some individuality to set them apart in the game. Cutscenes or animations are also prime candidates for custom recording work. Outside of the sound list, you will need some type of recording report to track what actually happens during the recording session (see Figure 1). While session notes can be scribbled on a piece of scrap paper, the time it takes to create an official comprehensive reporting system will be more than made up when you are ready to edit and mix down your effects. A typical report will have the sound or sound group name, along with take numbers, the presence of the right and left audio channels, and some basic equipment setup information. The recording report should also include some type of indexing scheme that matches your equipment or saving process. DAT index numbers, minidisc tracks, file names or SMPTE Time Code will work for the task. Also be sure to leave room for miscellaneous notes on each take. You may know right away when something is particularly good or bad and can make note of it. With a well-planned recording report and a comprehensive sound list available you just need something to record.
Through the years, sound designers have relied on all manner of noisemaking objects (dubbed "props") and tricks to create the sound they are looking for. When the actual object needed for recording isn't available or is too unwieldy for the studio, creative improvisation often works best. It's a good idea to start a prop box filled with all kinds of noisemakers long before a recording session takes place, preferably at the start of a project. Props can be almost anything from baking soda to stalks of wheat; the only limit is your imagination. In situations where a prop might be destroyed during the take, such as the shattering of a glass, make sure to get multiples for practice or mistakes. It's also a good idea to have on hand various wearable prop items in your collection of goodies. The sound of a trench-coated hit man drawing a pistol from his pocket is going to be a lot more convincing if a trench coat is actually worn in the take. The same notion applies for shoes, armor, helmets, jewelry, and specific types of fabric, such as silk and wool. Foley pits are another addition to your recording area if you anticipate needing to do footsteps. Essentially these pits are lowered sections of floor filled with different walking surfaces. Sand, rock, water, and tile are all common pit fills. A simple inexpensive pit can be constructed out of a deep two-by-four frame (see Figure 2). Materials you might work with, such as concrete, flagstones, metal grating, and even sod, can be purchased at almost any major hardware store.
The space in which you record a sound is almost as important as the sound itself. If you don't have access to a sound recording facility or are working within a tight budget, almost any moderately sized room, preferably one that is isolated, can be adapted to the task. The most pressing concern with a recording room is controlling the acoustics and, if possible, using them to your advantage. Problems generally arise from sound bounces, where a sound wave traveling from its source is reflected off a hard surface, such as a table or wall. In a small space, these reflections are usually not perceptible to the human ear; in larger spaces they can manifest themselves as an echo or multiple dispersed echoes, called reverberation. These alterations to the sound, sometimes referred to as coloration, can often be dramatic, not only betraying the characteristics of the recording space, but also modifying the fundamental characteristics of the sound itself. Luckily, a little knowledge of sound waves and the physics involved can help eliminate such problems before they start. Sound waves are normally created through the elastic compression (the rapid pushing together) and rarefaction (the rapid pulling apart) of air molecules (see Figure 3). While one phase of compression and rarefaction is called a cycle, the physical distance each cycle covers (noting that sound travels at roughly 1,130 feet per second) is referred to as its wavelength. The number of cycles that occur in a single second are measured as a frequency in hertz (Hz). Humans with exemplary hearing can detect frequencies from about 20Hz to 20kHz, although you'd be hard pressed to find any modern audio standard delivering the entire range.
Because sounds are physical waveforms moving through air, they are free to intermix. When two sound waves encounter one another, their interference can be termed either "in phase," where both waveforms are perfectly aligned, or "out of phase," where the two waveforms are shifted (phase-lagged) apart. The result is a new waveform based on the sum of the displacement of each contributing waveform (see Figure 4). In the two most extreme cases, perfectly in phase and exactly 180 degrees out of phase, a pair of sound waves will double in amplitude or completely nullify each other, resulting in no sound. Either case is a recording mess.
Sound waves have other important properties to consider when setting up a recording session. Each waveform's compressions and rarefactions also have a strength known as the intensity. The spread of values from minimum to maximum intensity is the sound's dynamic range. When a sound wave radiates from its source, it starts with a uniform intensity pushing on a volume of air. As it continues to travel away from its source, the expansion continues, but it has to push increasingly large volumes of air to achieve the same result. Without amplification, the sound's acoustic pressure dissipates, decreasing its intensity. The same behavior can be observed in any waveform outside of a vacuum. For example, as the shock waves from an earthquake spread from its epicenter, the area affected increases while the relative strength of the shock waves declines. Sound pressure varies inversely with the square of the distance from its source. In numeric terms, an audio wave's intensity drops by six decibels (a logarithmic measurement of a sound's loudness) with each doubling of its radial distance from the source. This exponential relationship is known as the inverse square law, and keeping it in mind during any recording process can be extremely helpful. By increasing the distance from your microphone to the closest source of reflections (at least two to three times greater), you can dramatically diminish the intensity of any audio coloration (see Figure 5).
Of course, providing increased distance from the source of reflections is not the only thing you can do to ensure a clean (sometimes called a "dry") recording. Soundproofing the recording space from outside interference is a good start. While full sound studio setups can run into the millions of dollars, small changes to any space used for recording can make a big difference. Unless they were designed for acoustics, rooms with windows are not advisable. Any doors in the recording space should be replaced with the solid-core variety and the walls should be soundproofed with insulation. Felt-padding or weather-stripping doorframes and air vents can also help eliminate vibrations caused by air pressure variations in a building. Music supply companies sell wide varieties of diffusers, used for dispersing an audio reflection evenly, and dampening tiles, used for trapping sound. Hanging these on the walls of your recording space near the closest reflection areas to your audio source or in the direction of the microphone's pickup (see below) can work dramatically well. If you're on a very tight budget, consider purchasing acoustic blankets. More often found at theatrical production houses than music stores, they can be hung or draped about for adequate effect. ________________________________________________________ |
|
|
Features
