When Kristen is watching the YouTube video, her girls all wake up and start to talk about hearing something. The youngest one on the bottom bunk is shown waking up with the string of lights above her bed on. When the scene switches back to her a moment later, the lights are off.
In YouTube is not possible to hide a 17kHz voice, because the audio is capped at 16kHz.
At 12:57- Inhaling asbestos fibers causes asbestosis which is a chronic lung disease.