Mole vs Sound

Mole

name
  • A river in Devon, England, tributary to the Taw. 

  • A river in Surrey, England, tributary to the Thames. 

  • A surname. 

Sound

name
  • Synonym of Plymouth Sound, Devon, England. 

  • The strait that separates Zealand (an island of Denmark) from Scania (part of Sweden); also sometimes called by the Danish name, Øresund. 

How often have the words Mole and Sound occurred in a corpus of books? (source: Google Ngram Viewer )