When Jesus walked on this earth 2,000 years ago, he certainly taught his disciples through his words, but he also set an example for them to follow.
This was the case especially with regard to prayer.
Jesus was frequently found praying in silence, going away from the crowds to pray without vocalizing.
However, he also prayed out loud, using words that his disciples could hear.
The Catechism of the Catholic Church explains how Jesus taught his disciples the importance of vocal prayer:
Vocal prayer is an essential element of the Christian life. To his disciples, drawn by their Master's silent prayer, Jesus teaches a vocal prayer, the Our Father. He not only prayed aloud the liturgical prayers of the synagogue but, as the Gospels show, he raised his voice to express his personal prayer, from exultant blessing of the Father to the agony of Gesthemani.
If we want to imitate every aspect of Jesus' life, we need to make sure we participate in both silent and vocal prayer.
This could mean praying vocally by ourselves but even more importantly with others.
We are challenged to vocalize our prayers in front of other people and to share with them our interior life.