you are likely to find Voice in/at/on Telephone. Voice is related to Pitch. Pitch is a synonym of Track. 
Southwest is a type of Direction. Northwest is a type of Direction. Northwest is a type of Location. 
Telephone <--AtLocation-- Voice <--RelatedTo--> Pitch <--Synonym--> Track 
Southwest --IsA--> Direction <--IsA-- Northwest --IsA--> Location 