I believe that when this happened in the OT it was rare. And significant events in the lives of Abraham or Moses, etc as they were part of redemption history and needed to be supernatural events to mark them as clearly God intervening in the lives of these men.
We have examples in the NT also. And they too are rare and mark significant events related to redemption history, declaring Jesus as the Son of God and to be heard over Moses and the prophets, and there is Pauls conversion which marks a significant vessel to write much of the New Testament.
What I see in these patterns is that there is absolutely no indication that God will not speak audibly to someone or a whole group of witnesses if he so chooses today. But I would expect that to be a significant event marking it as some kind of prophesy fulfilment in the history of redemption or something. Like maybe something like that would happen when something in Revelation is being fulfilled, or one of the details of an OT prophecy that has a further end time fulfilment.
I wouldn't say that God doesn't do it today. Only that nothing has required Him to do so. We are in that stage in the redemptive time line where we are to be winning souls in the power of the Holy Spirit and God is speaking through us in the prophets voice, (or at least those of us surrendered to him, and filled with the Holy Spirit).
We know that there will be the voice of the Archangel when the trumpet sounds.
Maybe there will be a few more audible voice events.
One of the last ones, and maybe the last unless you include Jesus talking to Paul, was when God said, "This is my beloved Son, Hear Him" and He said this when Peter wanted to make a tabernacle for Moses and Elijah and Jesus, thus signifying that the time of the Law and the Prophets had been eclipsed by Jesus ministry and we are to Hear Him.
If there is another audible voice event it will be a few rare instances at most before the world ends and that would be no different than in the past. A very rare event marking significant developments in the Redemptive plan of God and the plan he foreordained to redeem mankind and wrap all things up and usher in the eternal kingdom of perfection and everlasting dwelling in righteousness.