Whether it is true or not that we fear silence because of the dread of that final pause when we are six feet under, we should never replace ‘silence points’ with redundant sounds like ah, eh and uhm.
Pause for two or three seconds and audiences assume you’ve lost your place; five seconds they think the pause is intentional; after ten seconds even the people texting can’t help looking up. When you start speaking again the audience naturally assumes the pause was intentional… and that you’re a confident and accomplished speaker. A poor speaker abhors a vacuum; only confident speakers are secure with silence. Take one long pause to gather your thoughts and the audience will automatically give you speaker bonus points