By now you are probably getting a bit annoyed with the constant voice in your ears. Thankfully, NVDA offers a very nice 'Speech viewer' in which you can read what it speaks.
You can find it under 'Tools' in the NVDA menu. Just right click the taskbar icon or press NVDA + N.
Now you can read what NVDA says, you can toggle the voice to off, beeps only, and back on with NVDA + S.