Auxiliary audio devices are audio devices whose output is mixed with the MIDI and waveform output devices in a multimedia computer. An example of an auxiliary audio device is the compact disc audio output from a CD-ROM drive.
Control for auxiliary audio devices is provided by a software-controlled audio mixer. The mixer can reside on the motherboard of a multimedia computer, or it can be on an add-in sound card. The following illustration shows the conceptual audio-signal routing in a multimedia computer:
In this multimedia computer, there are two auxiliary audio devices: the CD-ROM and the external audio input. The external audio input is an input jack that allows the user to connect other audio devices.