spoken vs surd

spoken

adj
  • Produced by articulate sounds. 

  • Relating to speech 

  • Speaking in a specified way 

surd

adj
  • unvoiced; voiceless 

  • Involving surds, or irrational numbers; not capable of being expressed in rational numbers. 

noun
  • An irrational number, especially one expressed using the √ symbol. 

  • A voiceless consonant. 

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