The rationale behind fillers would be that we believe we ought to speak all the time whether giving a presentation or responding to questions. Silence, on the other hand, does not necessarily have to be uncomfortable. You'll notice that some experienced presenters take a little pause to gather their ideas and select the appropriate words if you pay attention. Indeed, a few secs of quiet allows you to organise your ideas more quickly than if you were still speaking, and it may even add weight to the presentation, and a presentation designer is aware of all this. Reach out to us to know more about presentation design services!