Confidence Monitoring means listening to the actual result
being recorded — critical to ensuring its quality.
[Analog reporters refer to this as "monitoring from tape."]
By definition, you will hear a very slightly "delayed echo" of what is being said
in the real-life sound environment.
If what you hear through your earphones is exactly in sync with the real-life
sound environment, you are merely "Monitoring from Source," listening
only to microphone activity — and in that mode
you CANNOT know for sure what is being actually recorded
on the disk or tape.
It is wise to occasionally switch between Confidence Monitoring
and Monitoring from Source (microphone-checking).
In either mode, occasionally listen to each channel
in turn, rather than muddled together in an all-source mix, which is
not very helpful when a single microphone or cable is having problems.