Vocal variety is the loudness or softness of the voice; the tempo which is how fast or slowly the words are delivered; and the pitch which is whether the voice is low and solemn, or high and excited.
Vocal variety can be rehearsed at home or mentally visualized if on a train on the way to the venue. Vocal variety becomes natural and ‘second nature’ to a speaker after a certain amount of time and practice giving speeches. Emphasis in the voice mainly comes, however, from entering into the speech that you are giving, living the situation you are describing and being the character being portrayed.
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