threshold vs sense impression

threshold and sense impression both are nouns.

Word	Noun	Adjective	Verb	Adverb
threshold	Yes	No	No	No
sense impression	Yes	No	No	No

As nouns, sense impression is a hypernym of threshold; that is, sense impression is a word with a broader meaning than threshold:

Other hypernyms of threshold include aesthesis, esthesis, sensation, sense datum, sense experience.

threshold (noun)	sense impression (noun)
the sill of a door; a horizontal piece of wood or stone that forms the bottom of a doorway and offers support when passing through a doorway	an unelaborated elementary awareness of stimulation
the entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close
the smallest detectable sensation
a region marking a boundary
the starting point for a new state or experience