First introduced by Microsoft in Windows 2000, DirectSound is an API that adds an additional software layer between applications and the sound hardware. This layer uses today’s high-speed CPUs to mix all waveform sounds before they go to the soundcard. This means that you could have a basic, two-channel soundcard, yet any number of applications could be producing sounds, and you would hear all of them. DirectSound enables the playing of sounds with very low latency and gives applications a high level of control over hardware resources.

By using the DirectSound interfaces in music applications, you can do the following:

• Play sounds from files or resources in WAV format.

• Play multiple sounds simultaneously.
• Assign high-priority sounds to hardware-controlled buffers.
• Locate sounds in a customizable 3-D environment.
• Add effects such as echo and chorus, and change effect parameters dynamically.
• Capture WAV sounds from a microphone or other input.