This passage recalls Genesis 3:1-10, where Adam and Eve, after sinning against the Lord’s command, hear the voice of the Lord walking in the garden and hide themselves because they are afraid. The ESV translates the Hebrew word for “Voice” as “sound” in Genesis 3:8 and 10, this seems to smooth out the KJV’s rendering; however, I don’t see either translation of the term to be problematic, seeing as the “sound of the Lord God walking” and “the Voice of the Lord God walking” would both refer to Christ, pre-incarnate, walking alongside His creatures. From the context of Hebrews 4:11-13, however, I think it is more likely that “Voice” is the appropriate translation, seeing as the themes of (i.)God’s Word, (ii.)man’s guiltiness, (iii.)man’s spiritual nakedness, (iv.)man’s inability to hide himself from God, and (v.)the necessity of man giving an account to God for his sin, are all present in Genesis 3:1-10 and Hebrews 4:12-13.
I think that the Holy Spirit is here alluding to Genesis 3:1-10 in this short section of the chapter, and if that is the case then the illustration vividly depicts the concrete nature of God’s presence in His Voice/Word, that is to say – it illustrates very vividly that Christ is that Word who sees through our shameful fig leaf coverings, who cannot be deceived by our even our best outwardly righteous garments sewn together in anxiety and pride and rebellion and fear. Christ is that Word of God who knows the very intentions of our hearts in all that we say and do, and who calls to us “Where are you?” not because He doesn’t know where we are, but because He is calling all men to repent of their sin, to come out from the trees, in other words, and come clean.
What is beautiful is that just as the Voice of God called out to Adam and Eve in Genesis 3:1-10, exposing their sin and bringing judgment upon them, but then covered their nakedness with the skin of an animal slain in their place, so too we read in Hebrews 4:12-13 of the Word of God exposing our nakedness and vile wickedness, but then covering us with His righteousness and intercession as our High Priest before God. The correlation here is amazing, and it leads me to think that the KJV did not mistranslate Genesis 3:8 & 10, but that the more modern versions seem to have done so in an attempt to make a smoother narrative flow. It would be interesting to find sound theologians who write about the exegetical/theological reasons as to why the Hebrew word translated as “sound” in the ESV seems to be better translated as “Voice.”