Audio PowerPoint should allow speed control.
Thanks for sharing your feedback with us Brazil, we have a quick question about your post. 1. Is this when you're in a Presentation? If yes, you can set the start time and speed of an animation effect by going to the "Animations" tab and the "Timing" group. Here's some more information here https://support.office.com/en-us/article/set-the-start-time-and-speed-of-an-animation-effect-bf8c1cb4-c827-48b6-b756-8c1a3e681a60