You will hear the audio normally while the transcript appears. When you have finished, set the output back to your speakers or headphones. To go back to your own microphone, just pick it again in the microphone menu.
You hear nothing? The output is set to Sight-Terp Audio rather than Sight-Terp Monitor. Sight-Terp Audio on its own swallows the sound.
Transcript stays empty? The input is still your microphone — change it in Sight-Terp's microphone menu.
Neither device appears? Restart the Mac and look again.
To remove it: run sudo "/Library/Application Support/Sight-Terp Audio/uninstall.sh"