* Projection: When you read aloud, you typically project your voice more than you do when you speak conversationally. This is because you want your voice to be heard by everyone in the room. However, when you speak conversationally, you only need to project your voice enough to be heard by the people you're talking to.
* Intonation: The intonation of your voice can also change when you read aloud. When you read, you tend to use a more monotone voice than you do when you speak conversationally. This is because you're focused on pronouncing the words correctly, and you don't want to distract from the meaning of the text.
* Pacing: The pacing of your speech can also change when you read aloud. When you read, you tend to speak more slowly and deliberately than you do when you speak conversationally. This is because you want to give your audience time to process the information you're reading.
* Accent: Your accent may also be more pronounced when you read aloud. This is because you're more focused on pronouncing the words correctly, and you don't want to distract from the meaning of the text.
The combination of all these factors can make your voice sound different when you read aloud than it does when you speak conversationally.