As to these kinds of prayers that are called vocal, I judge that for thee that art religious and art bound by custom and thy rule to say thy Breviary it is most expedient to say it, and that as devoutly as thou canst, for in saying of them thou sayest also the Pater noster and other prayers likewise. And to stir thee up more to devotion there be ordained psalms and hymns, and such other which were made by the Holy Ghost, like as the Pater noster was. Therefore thou shalt not say them hastily nor carelessly, as if thou wert troubled or discontented for being bound to the recital of them; but thou shalt recollect thy thoughts to say them more seriously and more devoutly than any other prayers of voluntary devotion, deeming for truth that, seeing it is the prayer of holy Church, there is no vocal prayer so profitably to be used by thee as it is. Thus shalt thou put away all heaviness, and by God’s grace turn thy necessity into good will and thy Obligation into a great freedom, so that it shall be no hindrance to thy other spiritual exercises. (John Climacus)

Vocal prayer can prepare us for listening.

With prescribed prayers, psalms, and hymns we can "warm-up" for the real deal.

In this way we put away the heaviness of our self-concerns and loosen our mind, body, and spirit to run with God.