A difference in speech pattern will change the intention behind your words.
Conversational speech is different to giving a presentation, speaking on the phone or recording a pitch to video
What things might you consider when speaking at a conference for instance?
Your intonation (your pitch pattern) will keep your audience engaged. There’s nothing worse than listening to someone speak in a quiet, monotonal voice about health and safety!!
Vary the pitch like in normal conversational speech, but still with the required intensity.
Projection and volume
You want to be heard, so projection and volume is key, especially if you're speaking to a room of 500 people.
Projection is created by finding the right resonance in the mask, and visualising a place to aim your voice at, where as volume is the loudness of your voice, which comes form the correct Diaphragmatic support plus resonance in the chest cavity. You'll need a certain amount of dynamics (changes in volume) and projection to communicate your message.