did you arm your tracks? if you didnt then its still possible to see the record button light up without any waveform being drawn or recorded on the track (hence no sound). kung merong waveform at wala paring tunog then it's possible you're monitoring through the wrong outputs.
Kit is right, inputs and outputs are determined by your soundcard/audio interface. at the left most portion of your screen you will see the details about the selected track, where the input is coming from, and where it is going. make sure you are hooked up to the correct channel. also, if you are using something like TotalMix (a mixer software that came along with your audio interface, make sure that you have chosen the correct outputs there, and that you have properly routed your signals).
ngapala, under devices go to VST CONNECTIONS, then click on "Add Bus" to configure you uotputs and inputs in case they weren't automatically configured.
Hope this helps.
hope this helps.