The invention of digital and desktop audio workstations (or DAWs for short) has
allowed multimedia experts and novices alike to manipulate audio files, music,
and sound in new and creative ways that were previously impossible or only doable
by large state-of-the-art recording studios. Most popular is the use of loops.
A loop is a short piece of audio, usually a sound effect or a royalty-free music file, that can be repeated over and over again to create a continuous, longer piece of audio. Some examples of common loops include nature sounds (like country ambience, rain, ocean sounds, trains, etc.), drum beats and grooves, and other types of atmospheric ambience. These looped sounds can then be used to create what is known as a sound effects bed, or a continuous atmospheric ambience, or even an entirely new song.
Productiontrax.com has a wide variety of loopable sound effects and royalty free music grooves and beats that you can use to create looped beds and music. Once you download the track you plan to use, you will need to import it into the digital audio workstation program of your choice. Popular DAWs for manipulating high quality audio files include Cubase, Logic, Digital Performer, Nuendo, Reason, etc. All of these programs have lower cost "lite" versions for less experienced users and are available for all platforms. You can also use other non-destructive audio editing programs, as many are available as freeware, shareware, or as low-priced stand-alone versions.
Whichever software program you use, you will need to locate your imported audio file, then simply create multiple instances of the file, set to playback one right after the other. Most of the above programs allow you to handle files like this visually, appearing as blocks on the screen. Simply line up the blocks so that they are all in a row and touching end to end. It may take some tweaking and additional audio-editing expertise to use just portions of loopable files to avoid pops and gaps. General practice is to locate the points within the audio file where the audio wave crosses the zero line, and make your cuts at these zero-crossings.
A quick word about MP3 files: MP3 files contain meta data that creates a split-second silence at the beginning and end of an MP3 file. For this reason, always use WAV or AIF files when working with loops to avoid gaps and silence in your loop. Alternatively, you can convert your MP3 files to WAV in your editor, and then trim the silence, creating a loopable audio file.
Once you have lined up your duplicate instances, simply save your newly created audio sequence (also called a digital mix-down, or bouncing audio tracks), and save your newly created file to your hard drive and, whallah, a continuously looped audio sfx or royalty free music track to bring into your video or multimedia program.