Networked voice communications runs at 8kHz sample rate, which is fine for voice. However this does not work so well for aural cue applications; it is often preferable to run the aural cue at 16kHz or even 24kHz since the upper audio bandwidth for the system is limited to half the sampling rate for the system.

In order to split out the communications and aural cue to allow the system to run at different rates, each application must run in it's own DSP card. It is not possible to run two models on one DSP card at different sample rates. However most ASTi processing platforms allow at least 2 DSP cards to be installed. This allows one card to provide the processing for communications run at 8kHz, with a second card providing the aural cue capability and can run at 16 or 22kHz.