Prayers are addressed to God, but they are also for the benefit of the people. If they cannot be heard by the audience, they should not be uttered in their behalf. I have been in some assemblies where it was not possible to discern when certain prayers commenced, or when they ended. This is something that is not to be tolerated. We must target the whole congregation being able to say "Amen, at the giving of thanks."
Scripture addresses the matter of public prayer, providing insight into the mind of the Lord on the matter. "I exhort therefore, that, first of all, supplications, prayers, intercessions, and giving of thanks, be made for all men; for kings, and for all that are in authority; that we may lead a quiet and peaceable life in all godliness and honesty. For this is good and acceptable in the sight of God our Savior; Who will have all men to be saved, and to come unto the knowledge of the truth. I will therefore that men pray every where, lifting up holy hands, without wrath and doubting . . . In like manner also, that women adorn themselves in modest apparel, with shamefacedness and sobriety; not with braided hair, or gold, or pearls, or costly array; but (which becometh women professing godliness) with good works" (1 Timothy 2:1-4, 8-9).
First, public prayer is broad in perspective: "supplications, prayers, intercessions, and giving of thanks." While there is diversity here, there is also focus. Supplications are earnest pleas. They are attended with by the element of urgency. Prayers are expressions of reliance upon God, including articulations of worship and adoration. Intercessions involving standing in the gap for other individuals, exercising our role as "kings and priests" unto God. The "giving of thanks" is a broad category that ranges from insightful thanksgiving for salvation to expressions of gratefulness for contemporary deliverance and strength.
These require us to view life from the heavenly perspective. We perceive life as an arena in which God works in response to our prayers. We will have to exercise diligence to maintain this perspective, but it can be done.