Read a sentence aloud and your speech is scored phoneme by phoneme. You see which sounds are weak and how to place your mouth and tongue to fix them.
People tell me my accent is off but never what to fix.
That is why this does not stop at one score for the whole sentence. Broken down sound by sound, the place where the score drops is the place to work on.
Do I need a quiet room?
Background noise makes the scoring wobble. Hold the mic close and use a quiet spot if you can.