Many times in the bible it is stated about the blind and deaf ( this is the unconscious, those that can hear the words preached, but not have any sense of what those words mean)...all those with ears listen ( well everyone has ears right?) But its the person with consciousness in christ (born again) that can truly hear, see and interpet the bible and make sense of Jesus's parables, threw the gift of the holy spirit.
Matthew 13:15
For this people's heart has grown dull, and with their ears they can barely hear, and their eyes they have closed, lest they should see with their eyes and hear with their ears and understand with their heart and turn, and I would heal them.
Deuteronomy 29:4
But to this day the Lord has not given you a heart to understand or eyes to see or ears to hear.
( enlightened or made aware of or conscious of )
Hebrews 6:4-6
For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, and have tasted the goodness of the word of God and the powers of the age to come, and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt.