Silence is the opposite of Conservation. Conservation is related to Preserve. 
Whisper is a different concept from Loud. Loud is the opposite of Silence. Silence is related to Very. 
Silence <--Antonym--> Conservation <--RelatedTo--> Preserve 
Whisper <--DistinctFrom--> Loud <--Antonym--> Silence <--RelatedTo--> Very 