The Divine Office or Liturgy of the Hours is the Church's daily prayer. The praying of it is an obligation for priests, deacons and religious; and is highly recommended for the laity as well.
Today on the liturgical calendar is the Memorial of Saint Alphonsus Maria de Liguori. He had much to teach about the Liturgy of the Hours. He said that in praying this liturgical prayer of the Church "God is honored, the fury of the enemy is repelled, and the divine mercies are obtained for sinners." He lifts up our hearts with these words but warns us that these things are true only if prayed in a "proper manner - carefully and devoutly."
Keep in mind first and foremost that the Liturgy of the Hours is a public prayer of the Church; but even when prayed privately as it often is, it's worth considering the advice of Saint Alphonsus when he said that the Divine Office is to be prayed "by pronouncing the words distinctly, devoutly." Rushing through it will likely deter the intention of authentic devotion.
Saint Cyprian wasn't shy about this topic either. He wrote: "How can you expect that God will hear you when you do not hear yourself? Prayer made with attention is the odoriferous incense that is most agreeable to God, and obtains treasures of grace." These edifying words also come with a cautionary remark: "The devil labors strenuously to make us say [the Liturgy of the Hours] with distractions and defects."
If we are to raise our hearts and minds to God in the praying of the Liturgy of the Hours, Saint John Chrysostom tells us that "we must dismiss all thoughts of the world." It's a good idea to spend a few minutes in silence before praying any hour of the Divine Office, to help clear the mind of any unnecessary thoughts, and help create an environment of tranquility.
There was a time in the Church when the Liturgy of the Hours had to be recited; that is, it was necessary to verbally say the words, even privately. Today this is not so, although it is always commendable to do so. It is not necessary to "recite" or "sing" the words when privately praying this treasure of the Church; thus when words are used like "recite" or "say" certainly this is literally true in a public setting; in a private setting, however, the words of the Liturgy of the Hours can be recited, said, or sung with the lips of the heart - but always with great love.