When your recording your voice over the instrumental track and microphone is registering in sequencer but you can't hear your voice to sing to the track. Where is the problem?
Using Reason6 with Windows7
You need to click on the monitor button. See Picture.
If you are getting signal once you have pressed the REC button and than you click the monitor button and you do not hear anything than it would seem to be either the track it Muted, the Level is down, something in the Rack, or something to do with your audio device. In preferences Automatic Monitoring is select be default.
The whole thing here is you are getting signal into Reason so it must be something with the out following signal.
Found the problem. When using ASIO4ALL driver, you have to go into the preferences, audio at the bottom of the list is Play In Background clicked it off and boom everything works.