ear to the ground vs observant

ear to the ground

noun
  • The practice or characteristic of carefully gathering information; a state or mindset of attentiveness. 

  • Pursuing the practice or having the characteristic of carefully gathering information; well-informed. 

observant

adj
  • Diligently attentive in observing a law, custom, duty or principle; regardful; mindful. 

  • Alert and paying close attention; watchful. 

How often have the words ear to the ground and observant occurred in a corpus of books? (source: Google Ngram Viewer )