tempo changes not there

I selected 4 sections 1 at a time and applied the tempo change to each selection before going on to the next. When I replayed the audio the changes were not there. This is my first day using Audacity. I hope it is something simple to correct.

Did you check your work on One before you went on to Two.

Effect > Change Tempo has several different ways to tell it what to do. Which did you use and what were your correction values?


I started over. I defined 1 loop. I applied a tempo change of -.18. Then I used preview. It did not sound like the tempo changed. I hit OK and played the file. The loop section did not sound any different. Is defining a loop the way to make a selection for tempo changes?