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.