Read Exodus 20
When I think of this I get the vision of Charlton Heston in Cecil B DeMille's film but that's not accurate.
According to what I read, Moses was still at the bottom of the mountain. Beginning at verse 18 the people address Moses right after God has stopped speaking. So I think there is evidence that when God gave the commandments everyone heard Him. Estimates place the number between 2 and 3 million people. Imagine the space they occupy and how the sound may carry. Was it a booming thunderous voice or perhaps everyone heard God as if He were standing close by. Either is possible but I think it important that God wanted to give His law to everyone. It wasn't some secret law that Moses came up with but God Himself spoke. It's not reserved for priests of prophets but for everyone. Also of note is the conviction and fear in the people from hearing God. That's what The Word should do to unrepentant sinners.
No workout today, rest and spend time with God.