Presentations sometimes include q&a time. So I'd just use an AAC app with text to speech feature. You can make it speak a prepared script for you and you can also type a response to somebody's question and make it speak the response. There are already people who use AAC for their presentations. Here's an example [https://youtu.be/9w\_DCcxvxS8?t=585](https://youtu.be/9w_DCcxvxS8?t=585) The guy with phone is a disabled activist and he's giving a presentation using AAC at a conference about AAC. He can't speak. So he's communicating by AAC the whole time. You don't have to make the whole presentation be spoken by machine. You can choose to say some sentences by speaking and openly stuttering and other sentences by machine.