Speech is related to Testimony. Testimony is related to Witness. Witness is a synonym of Find. 
Inquiry is a synonym of Research. Research is a synonym of Exploration. Exploration is related to Quest. Quest is related to Journey. 
Speech <--RelatedTo--> Testimony <--RelatedTo--> Witness <--Synonym--> Find 
Inquiry <--Synonym--> Research <--Synonym--> Exploration <--RelatedTo--> Quest <--RelatedTo--> Journey 