A couple things you can try, in addition to Jackie's suggestion:
First, in NVDA, press NVDA+control+r three times quickly, which will reset your configuration to factory defaults.
If something did get screwed up with your configuration, just removing NVDA might not fix that.
Second, with NVDA and Narrator running:
Open the Sound Volume Mixer (windows+r, sndvol, enter).
Make sure that NVDA doesn't have its volume down there, and that it's not muted.
Before you try this, make sure NVDA isn't set to no-speech--have it on Espeak, preferably. I know you checked that already, but something could be going on with your configurations.
It may be worth trying this idea before resetting your configuration, in case you don't need to reset.