Vocal variation, intensity, pacing and use of fillers are a part of which of the speaking competencies?

Vocal variation., intensity pacing and fillers are key elements for speaking competencies.
* vocal variations help the audience/ listener be engaged with the talk and be able to identify different moments within it for example feelings, or emphasis.
* intensity goes hand in hand with variations. It is also called voice intensity and it refers to the volume of the voice.
* Pace is the speed in which a person speaks. we need to be aware of the pace because if we speak very quickly, the listener will probably get lost. 
* fillers do not have a meaning but they are used for conversational purposes. Maybe to take a pause and think or to show comprehension or surprise. for example; um- ah- uh, etc.