Mental permissions have a distinct impact on the vocal range you produce. The voice is a peculiar thing - our sense of identity is tied up in it. How do we expand our sense of what is possible? Releasing tension is a process of vocal training, often, but integration is a function of working with your mind.
Let's think about this: as a child, you could flatten a restaurant with one big howl. It took very little effort. As an adult, it takes BIG effort to project your voice so freely, and yet your muscles are technically stronger. What gets in the way of the voice being powerful and effortless as we age?
Speaking well should be a part of a business plan, as a part of supply chain for ideas. Speaking in a town hall is the essence of managing the water cooler conversations for the next two weeks.
The only reason people don't walk out on some speakers is the same reason that you eat pudding in a hospital. You eat pudding because it's the only thing in front of you. Given better options, that pudding would be in the garbage.