Thought is a synonym of Opinion. Opinion is related to Emotional. Emotional is derived from Emotion. 
Hearing is a form of Hear. Hearing is related to Sound. Sound is related to Similar. 
Thought <--Synonym--> Opinion <--RelatedTo--> Emotional --DerivedFrom--> Emotion 
Hear <--FormOf-- Hearing <--RelatedTo--> Sound <--RelatedTo--> Similar 