Many a times God's voice is described as thunderous & powerful
All texts from NASB
Now when Moses went into the tent of meeting to speak with Him, he heard the voice speaking to him from above the mercy seat that was on the ark of the testimony, from between the two cherubim, so He spoke to him.
In the book of Psalms his voice is described as powerful & breaks the cedars of Lebanon
The voice of the Lord is powerful, The voice of the Lord is majestic. The voice of the Lord breaks the cedars; Yes, the Lord breaks in pieces the cedars of Lebanon.
Also in the book of Ezekiel it also described as being heard outside the courtyard
Moreover, the sound of the wings of the cherubim was heard as far as the outer court, like the voice of God Almighty when He speaks.
Did God whisper when he spoke to Moses in order for his voice not to project itself beyond the court yard?