17.3 Downloadable Sounds
Downloadable sounds (DLS) is an extension to General MIDI that allows customizing the available MIDI sounds by temporarily replacing standard ROM-based MIDI wavetable instrumental sound samples with sound samples loaded from disk. DLS samples can be instrumental sounds, sound effects suitable for games (e.g., lion roars, tire squeals, or a machine gun firing), or even voice clips. In addition to customizing the available sounds, DLS allows software developers to ensure consistency across different sound cards and platforms, for example by replacing ROM-based piano samples with DLS piano samples to make sure everyone hears the same piano. DLS Level 2 is supported by the DirectMusic component of Microsoft DirectX 7.0 and later running on Windows 95/98/2000/XP, and is used by an increasing number of games, education packages, multimedia encyclopediae, and similar software.