In Genesis 21:7, this signifies to implant truth from good, or something spiritual from a celestial origin. (Arcana Coelestia 2643)

In Psalm 8:2, this signifies that praise can come to the Lord only through innocence, for this alone effects all communication and all influx. (Arcana Coelestia 5236[4]) 'The nurse,' in Genesis 24:59, signifies a state of innocence. 'The nurse,' in Genesis 35, signifies hereditary evil. 'A nurse,' as she feeds and nurses an infant, properly signifies the introduction of innocence by the celestial spiritual. But when 'Deborah, the nurse of Rebecca died and was buried,' it signifies that hereditary evil which the Lord received from His mother, which was nourished from infancy just like with other people, was later totally expelled forever.

(Odkazy: Arcana Coelestia 3183)

“Hearing” in the Bible means more than just the collection of atmospheric vibrations: It represents receiving and understanding new ideas, particularly those from the Lord. On a deeper level it represents obedience, because we must understand to obey. This also is reflected in natural language, in which we often use “hear” to mean “obey.” There are many shades of meaning beyond that, depending on context -- who is hearing whom, and what the subject at hand is.