Applies to: All interfaces with 5 PIN MIDI in and out ports
MIDI data itself does not emit any sound. Therefore if you have connected a stage piano for example that has a MIDI output to the MIDI input on your interface you will not hear any sound coming out of the interfaces audio output.
In order to hear sound you will need to create a VST instrument track within your DAW, making sure to set the MIDI input to your interface and setting the MIDI channels to receive on as ALL.
Once you have done this you should find that when you press a key on the instrument or MIDI controller that is connected to the interfaces MIDI input, you then hear the output through your interface, providing it has been set as the audio output device within the DAWs audio settings.