It is not impossible to hear the Voice of God, but you must listen.
Everyone has ears…
But not everyone has spiritual ears.
The Voice of God can only be heard with spiritual ears. Because God is spirit, His Voice is spiritual. John 4.24
It is necessary to be in spirit to listen to It.
The human voice is heard with physical ears. The Voice of God is spiritual and is heard with spiritual ears.
From the Spirit of God to the human spirit.
How can you be in a spiritual state to listen to the Voice of God? When your intellect meditates on the Word of God.
On a Sunday, the apostle John was in the spirit. Revelation 1.10
His thoughts traveled with the thoughts of God.
He meditated on the Words of Jesus and the facts that had to do with Him. His teachings, His promises, His glory… Then, behind him, he heard Great Voice.
Though it was loud like a trumpet, only he was able to hear it.
The same happens with those who are in spirit. Only they can hear the Voice of God.
They listen and obey.