During the listening exercise I couldn't even hear 'dem' being pronounced. I turned my computer up and slowed the speech down and heard a small soft 'em'. Is this just the TTS or is this (very quietly) how 'dem' is actually pronounced ?
I'll just make a formal comment so that the developers see this.
When the audio is being played I believe that the user can barely hear the 'dem' in this sentence.
I hope that a developer sees this and fixes the issue.