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 machine-gun fire), 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.