Voice Speed Adjustment by Level
We've implemented voice speed adjustments based on user level. When you select Level 1 or 2, the speech will be a bit slower.
If you find the speech too fast and overwhelming, try choosing Level 1 or 2. (Note: The voice may sound slightly unnatural.)
However, if you can understand at least half of what is being said, Level 3 or above is generally more suitable. A difficulty where you miss about half of the speech is considered just right! 
You can change the level by tapping the flag button located at the top left corner of the first home tab.