detect

verb
  1. To discover or identify the presence or existence of something, often something that is not immediately apparent or is hidden. verb
    The scientist used a special instrument to detect the presence of radiation.
    It can be difficult to detect subtle changes in someone's behavior.
  2. To perceive or discern something using the senses, particularly sight or hearing. verb
    The dog can detect sounds that are inaudible to humans.
    She detected a hint of sarcasm in his voice.