Surprising as it is, there are a lot of models and actors in entertainment are rather quiet when off screen. These introverts can be successful in the industry, even if they aren't peppered throughout the tabloids for spouting off in public. Being heard is important, but more important still is being understood.
As an actor, the audience can't follow your character if they don't understand your speech (as well as movement and expression). For those who aren't naturally going to project their voices, learning how to be heard effectively can be as simple as a little practice.
Susan Berkley is not only a voice over artist (you know her as the voice of AT&T), but also the author Speak to Influence: How to Unlock the Hidden Power of your Voice and the president of The Great Voice Company. Her advice? Start by believing that you deserve to be heard. Insecure people often speak softly. Remind yourself that your ideas are as important as anyone else's.
Then start weight lifting with your lips! One very simple exercise Susan recommends is using tongue twisters to polish your clear vowel and consanant sounds. Try these several times a day for the next week and give your lips and tongue a good workout, too!
Green tea ice cream is a treat to eat
Mean men may cause harm
Go with the flow to stay in the know
Ed said get into bed
She lost her poise after hearing the noise
I knew the crew in a blue canoe
The next time you're in front of the camera, your lips will be primed and confident -- and everyone will know exactly what you are being hired to share (which will get you hired again soon)!