The voice should not be languid, nor feeble, nor womanish in its tone — such a tone of voice as many are in the habit of using, under the idea of seeming important. It should preserve a certain quality, and rhythm, and a manly vigour. For all to do what is best suited to their character and sex, that is to attain to beauty of life. This is the best order for movements, this the employment fitted for every action. But as I cannot approve of a soft or weak tone of voice, or an effeminate gesture of the body, so also I cannot approve of what is boorish and rustic. Let us follow nature. The imitation of her provides us with a principle of training, and gives us a pattern of virtue....
Men of the world give many further rules about the way to speak, which I think we may pass over; as, for instance, the way jesting [joking] should be conducted. For though at times jests may be proper and pleasant, yet they are unsuited to the clerical life. For how can we adopt those things which we do not find in the holy Scriptures?
We must also take care that in relating stories we do not alter the earnest purpose of the harder rule we have set before us. "Woe unto you that laugh, for you shall weep", (Luke 6:25) says the Lord. Do we seek for something to laugh at, that laughing here we may weep hereafter? I think we ought to avoid not only broad jokes, but all kinds of jests, unless perchance it is not unfitting at the time for our conversation to be agreeable and pleasant.
In speaking of the voice, I certainly think it ought to be plain and clear. That it should be musical is a gift of nature, and is not to be won by exertion. Let it be distinct in its pronunciation and full of a manly vigour, but let it be free from a rough and rustic twang. See, too, that it does not assume a theatrical accent, but rather keeps true to the inner meaning of the words it utters.
On the Duties of the Clergy, Book 1