If anything has changed during the twentieth century, it is the perception of the phenomenon of music. The irruption of sound into our lives is accompanied by changes in the use, understanding and enjoyment of music. The liturgy employs music as a sensible element for celebrating the Word and singing the same Word in the sacraments, in the liturgy of the hours and in prayer. For centuries the music was a bridge for the transcendent, today this element is thoroughly affected by the influences of the omnipresence of sound and of the challenge of real sound, that is of authenticity. We will try to respond to the question of what is changing in our societies in the matter of listening, while the liturgy continues to use sound as an element of perceiving the Mystery of God. The attention to the theological weight of these questions will underline the importance of paying attention to the contemporary world of sound for a liturgical understanding.