Ground floor · your voice
Say the line as one piece. Not fast — joined. If there is a silence in the middle it fails, and you will be shown exactly where it was.
I go on.
This browser cannot record. You can still hear the line and read how it works, but the check needs a browser with microphone recording.
Silences shorter than 120ms are ignored on purpose. Sounds like t, k, p and b are made by stopping the air, so they contain silence — counting those would fail you for pronouncing consonants.