People remember your point long after they forget your voice cracking on it.

During a presentation your attention is aimed at yourself, so a shake in your voice sounds enormous from in there. The room’s attention is aimed at what you are saying, and that is the part that gets stored. A week later someone will repeat your idea back with no memory of how it sounded coming out.

Write down the one sentence you want people to leave with and treat everything else as delivery. When your voice goes, keep going and say the sentence anyway. Afterwards, ask a friend what they actually remember.