Genesis 3:8– And they heard the sound of the Lord God walking in the garden in the cool of the day, and the man and his wife hid themselves from the presenceof the Lord God among the trees of the garden.

One way I’ve tried to explain “hearing the voice of God” to my kids was for them to understand their conscience.  That whenever you inwardly sense something is wrong, God uses our “conscience” to convict us to do something, refrain from something, or confess to something we did or didn’t do… (Romans 2:14-15)
Here in Genesis we see the conviction of Adam and Eve’s conscience of sin.  That as soon as they heard “the sound of the Lord God” their sin caused them to hide themselves from God.  Since God is perfectly holy, their sin caused them to fear and hide from His perfection because He exposed their shame.(Genesis 3:7)
This is why understanding the gospel of Jesus Christ is important for us to abide in.  Because God created us all with a conscience, but sin without consistent confession and repentance will cause us to hide from God, hardening our hearts and conscience. (1 Timothy 1:19) 
So like Adam and Eve, we may “hear the sound of the Lord” but hide in fear, instead of coming to Him to be covered by the blood of Christ for forgiveness and cleansing.  The blessing of “being covered” by the Lord is a clear conscience before Him, not fearing the exposure of sin and shame that causes us to hide from God and people. (1 Timothy 1:5, 1 John 1:9-10, 1 John 3:21)
Paul commanded that we “workout our salvation with fear and trembling”, because ultimately we have to live with ourselves before God.  Like I told my children, having “good behavior” before your parents, while living with a tormented conscience is self-torture.  The goal is to not hide from conviction, but “own it” for the sake of your own soul of unhindered fellowship in Christ, and sincerity with others…(Philippians 2:12. 1 John 1:6-7)
Faith in Christ comes with the blessing of knowing He bore our sin and shame in His body, prayerfully embrace this promise-In His Love,Ld