Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
In the first place he must correct all faults of pronunciation, and see that the utterance is distinct, and that each letter has its proper sound. There is an unfortunate tendency in the case of some letters to pronounce them either too thinly or too fully, while some we find too harsh and fail to pronounce sufficiently, substituting others whose sound is similar but somewhat duller.
For instance, lambda is substituted for rho, a letter which was always a stumbling-block to Demosthenes; our l and r have of course the same value. [*]( The mis-spelling of flagro as fraglo exemplifies the confusion to which Quintilian refers. A similar, though correct, substitution is found in lavacrum for lavaclum, etc. See Lindsay, Lat. Langu., pp. 92 ff. ) Similarly when c and g are not given their full value, they are softened into t and d.
Again our teacher must not tolerate the affected pronunciation of s [*]( Quintilian perhaps alludes to the habit of prefixing i to initial st, sp, sc found in inscriptions of the later Empire. See Lindsay, op. cit. p. 102. ) with which we are painfully familiar, nor suffer words to be uttered from the depths of the throat or
when the stops which produce the treble notes are closed, and a bass note is produced through the main aperture only.
He will also see that final syllables are not clipped, that the quality of speech is continuously maintained, that when the voice is raised, the strain falls upon the lungs and not the mouth, and that gesture and voice are mutually appropriate.
He will also insist that the speaker faces his audience, that the lips are not distorted nor the jaws parted to a grin, that the face is not thrown back, nor the eyes fixed on the ground, nor the neck slanted to left or right. For there are a variety of faults of facial expression. I have seen many, who raised their brows whenever the voice was called upon for an effort,
others who wore a perpetual frown, and yet others who could not keep their eyebrows level, but raised one towards the top of the head and depressed the other till it almost closed the eye.