Why is the Canon of the Mass silent?
According to the great mediæval English canonist Lyndwood, the answer is Ne impediatur populus orare, "Lest the people be hindered from praying".
(When at the Novus Ordo, I attend closely to the words of the Eucharistic Prayer - one wonders how many do - and even follow along in the Latin; but at the Traditional Mass, one has, surprise surprise, a greater freedom.)
Many times I read along while the priest offers up the Sacrifice, but, as I have grown to know the Canon and the gestures of the priest, I can lay aside my missal, and pray in general terms corresponding to the priest's liturgy*.
[* I call it that because there is an important, oft-forgotten principle: "every man in his liturgy", that is, following the teaching of Pope St Clement I in his Epistle to the Corinthians (chapters xl and xli), we ought each of us play our assigned part, not usurping others while neglecting our own.]
But twice recently, in Rome and in Melbourne, I followed another inspiration, and while the priest entered alone into the Canon in quietness, I read the psalms &c. of the Præparatio Missæ: Psalms 83, 84, 85, 115 and 129, plus their following versicles and orations. These prayers for use before Mass - first appearing in Western tradition about a thousand years ago, and still in the 1962 Missal for recitation pro opportunitate; indeed, a bishop being vested before pontificating was appointed to read them with his assisting canons - are, I find, also suitable to pray while the sacred mysteries are being consummated. The psalms are so many prophecies and foreshadowings of what God shall do, and now has done, in saving us by the Sacrifice of the Cross made present at Mass; and the subjoined prayers help prepare one for Communion, relying upon the aid of God the Holy Ghost.
All one must do, is keep an eye on the altar, and at the Consecration bow low, at the Elevations look up and worship...
I have previously blogged on praying the Canon: