Whisper is the opposite of Call. Call is related to Tone. Tone is related to Note. Note is related to Letter. 
Other is similar to New. New is the opposite of Ancient. 
Whisper <--Antonym--> Call <--RelatedTo--> Tone <--RelatedTo--> Note <--RelatedTo--> Letter 
Other <--SimilarTo--> New <--Antonym--> Ancient 