masking vs sense impression

masking and sense impression both are nouns.

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

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

masking: the blocking of one sensation resulting from the presence of another sensation
sense impression: an unelaborated elementary awareness of stimulation

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

masking (noun)	sense impression (noun)
the act of concealing the existence of something by obstructing the view of it	an unelaborated elementary awareness of stimulation
scenery used to block the audience's view of parts of the stage that should not be seen
the blocking of one sensation resulting from the presence of another sensation