I was reading some time ago an article in an American Orthodox periodical about whether the Eucharistic Prayer should be audible or silent. It is sometimes illuminating to see how our Western scene looks from the other side of the Eastern wall. Frankly ... I hate to interfere in the religion of others, but I feel strongly about this ... in my view, Byzantine Christians should stick to their traditions.
In the West, the EP has been audible in the C of E since 1559 and in most of the rest of the West since the 1970s. The Orthodox writer drew attention to listener fatigue; among RCs, he said, the audibility of the EP has led to an almost universal preference for the shortest EP (and it is indeed very short). In the C of E, he thought, the EP is commonly regarded by the laity as an irrelevant clerically-intruded piece of boredom which merely delays the all-important act of Communion.
I think he's absolutely right. And, looking at our Catholic Anglican tradition, I suspect that one reason for it is this: in our context it has seemed of crucial importance to avoid sacrilege by making our people understand that the Eucharistic elements truly are the Lord's Body and Blood. Especially since the restoration of mass communion, we have constantly (and probably rightly) postponed everything else to this agenda. But the centrality of Sacrifice, in the last resort, is more important than the worship or reception of the Sacramental Christ. I hesitate to blunder carelessly and over-simplistically around in so great a mystery; it is certainly true that both ....and is more important than either ... or. But, to be simple and crude, the Eucharist is firstly a sacrifice; only when we have said this do we go on to say that it is (we can't get away from the terminology of our Jewish roots here) a communion sacrifice. In the last resort, the Lord's Body and Blood are present substantialiter et realiter upon our altars primarily to be the propitiatory sacrifice which (since the first Holy Week) replaces the the Temple cult; secondarily, to be received so that Christ's Body and Blood can (Dr Pusey's banned sermon citing a great crop of Eastern Fathers is good on this:) be commingled with ours; thirdly, to be adored. Look at it diachronically: most Christians in most Chrisian centuries have attended Mass without communicating. S Pius X's great campaign for Frequent Communion does not need to be denigrated but it is not simpliciter the whole Christian tradition.
Back to the EP. If it is to be audible, its text should make very clear its sacrificial nature, and clergy-talk ('Today we are offering this Holy Sacrice especially for', for example) and sermons should frequently emphasise this. Or it can be done done silently; catechesis will have no trouble explaining that it is silent because it effects the great act of consecration and sacrifice; silent becuse it effects this without essentially needing lay participation or even understanding; silent because the priest is in the holiest possible commerce with God rather than saying something for the interest, diversion, or even edification of the people.
If it can't be said inaudibly, the next best thing is that it should be said very quietly. Yes, I know the OF rubrics specify an audible voice. But they do not say that the priest should bellow nor that there should be electronic amplification. If it is important that the people should hear the prayer, well, any schoolmaster knows that the best way of securing dead silence in a classroom is by speaking very quietly.