habituation

/həˌbɪtʃuˈeɪʃən/
noun
  1. The process of becoming used to something, so that it no longer causes a strong reaction.
    • The psychologist studied habituation in infants when exposed to new sounds.
    • Habituation to loud city noises happens quickly for most people.
    • After years of living near the airport, habituation made the plane noise barely noticeable.