How does the intended audience influence the tone of speech?

The intended audience influences the tone a lot. For an example, what tone would you use for a children's book / A book reading to kids? You would use a playful, or funny tone to keep the children entertained. You wouldn't likely use a strong, professional tone with them. If you was talking to group of college kids, or writing a college text books, what tone would you use? You would most likely use a professional, and serious tone since they are in college. Another little example, what tone do you usually talk to your pet in? Even though they don't understand us, we usually talk to our furry little friends in a high-pitched voice. Why? Maybe Because we know that they have tiny minds.