Audio Settings
Enable Input Monitoring
(ASIO Only) – When this checkbox is enabled (and ASIO is selected in the Driver Type combo) then RealBand will take the ASIO input signal from input port number 1 and send it to output 1 so that you will hear the input through the speakers. You can apply real time effects to the monitored input by selected "Input" in the top combo box of the DirectX/VST Real Time Effects dialog. You can then select up to 4 DirectX or VST effects.

If you don't have an ASIO sound card use http://www.asio4all.com/