Resonation is your key to effective communication. If you say or sing something, what your listener "hears" is determined by the WAY you do it...
Let me explain:
If your throat is somewhat closed and/or your airstream (power) is not supported and controlled, your resulting sound will not be perceived as important or confident. Your message will be "I'm not sure about this", "Don't eat me for saying this" or "It's ok if you don't listen to this".
Here is an example:
I was listening to NPR this morning and there was a hilarious bit about the note "Bb". There was an experiment someone did (this person may need a life) near a pit of alligators. He played a Bb on a tuba, and the gators started roiling and splashing around because they thought they heard a big rival intruder coming. No note except a Bb did the trick. Follow this link http://www.npr.org/templates/story/story.php?storyId=5500502 for more of the story.
Now I'd like to see a further experiment. I bet if the guy played a Bb on a kazoo or flute, the gators would have ignored it. The resonation caused by the tuba communicated the message they "heard" that made them go nuts.
Conclusion: If you want your listener to "get your message", do it with an open throat. Your vocal cord buzz will then be able to reach all your resonation zones, and your sound will be rich and full. For help with resonation, check out my vocal training course at www.judyrodman.com
ALSO: if you're near a gator pit, don't voice a low "Bb". Do it in falsetto :)