There is a technique in acting preparation called "scoring a script": the actor marks up the script’s dialogue according to the actor’s considered way to say a line (or, for that matter, when to move one's body, or lift one's hand to the face). The actor chooses her "line readings" in advance of performance, designating on the dialogue page where the accented word or words in a sentence should be, and where the pauses will be between words and sentences, etc.
The actor next commits those "scored" line readings to memory in rehearsal, and then in performance
attempts to recapitulate them in creating the form the rhythm, the overall sound, of the delivered dialogue, all according to the precise predetermined in rehearsal ‘script scoring’. It is a very detailed, precise--and for the most part highly mechanical--procedure.
For the most part I would argue, it is a technique to be avoided, except by the most expert actor. Such over-wrought "scoring" can lead in lesser hands to mechanical, robotic performances, devoid of any living reality--and therefore any audience feeling involvement.
In such instances, I would advise an actor to leave the physical "scoring" of voice and face and prop-use to the natural unconscious emotional scoring that occurs in performance, let the variety of character emotions truly felt naturally and spontaneously produce the varied external expressions of voice and body; let inner emotional impulse create the way in which the "line" is said in performance, or the way the body reacts during the playing of the scene, or when the hand moves to the face.
* * * * * * * * * *
To be fair, however: in the hands of an experienced actor, who is not seeking to "set" line reading in advance of performance, but in "scoring: she is seeking a character's possible emotional content which underlays the dialogue and all other external expressions. With such a rehearsal approach, the expert actor's "scoring" a performance is a fine and time honored method of actor preparation.
When I was a young actor, acting in plays by George Bernard Shaw, I was instructed to simply follow the rhythmic, accented and tonal flow of Shaw’s (the character’s) dialogue and I would "find the character": that is, in the rhythmic and accented cadence of Shaw’s words I would discover the emotional essence of the character I was playing. Speak like a Frenchman, you will feel like a Frenchman. Speak like a gentleman, you will feel like a gentleman. Speak like a whore, you will feel like a whore. Speak like a Fascist, you will feel like a Fascist. Form follows function. Inner truth can be activated and revealed by the shape of outer form. They are coexistant and symbiotic, especially in the hands of an expert actor.
Working with Shavian dialogue in such a way was a sublime manifestation of an "external to internal" approach to acting preparation; following form to discover function. This formal "pre-scored" (by Shaw in this case, in his very precise use of language/dialogue), the actor's spoken release of his language would be used to uncover the emotional truth beneath it. To wit: when playing Shaw, all you had to do was ride the verbal horse; follow the rhythm and pitch and pace of Shaw’s dialogue and emotional truth, and the race would be run; you would find in his words the essential nature of the character you were playing. (Interestingly enough, Shaw was a great music critic before he became an accomplished dramatist. It was if, in his highly structured dialogue in all his plays, he was saying: sing my music and the the soul of my singer--the actor-as-character--will be revealed to you!)