The spaces between sentences become quieter after an effect, but the final consonant of a soft word has also vanished. That is a reason to inspect the processing, not simply celebrate the silence. A noise gate responds to signal level rather than understanding the meaning of speech.
Read the threshold as a decision boundary
The Audacity Noise Gate manual explains controls that reduce sound below a chosen threshold, with timing settings affecting how the gate opens and closes. It is not a tool that independently identifies every unwanted sound while preserving every desired one.
Choose a revealing test passage
Use a copy of a short passage containing ordinary speech, a quieter phrase and a pause. Compare the original and processed versions at a sensible listening level. Listen especially to word beginnings, trailing syllables and breaths that belong naturally to the delivery.
Do not publish a universal setting from this experiment. Microphone level, speaker, room and processing chain all affect what a threshold encounters. A value that suits one passage can cut into another.
Judge the transitions as well as the gaps
An abrupt change between a quiet gap and a noisy spoken section may attract more attention than the original steady background. If speech suffers, reduce the processing or leave the passage untreated while considering another approach. Silence is not the only measure of a clear edit.
For the next recording, revisit the room before the effect menu. A gate can serve a specific editing purpose, but it does not remove the need to capture usable speech or to listen critically after processing.