Audio problem: When Karen is in the house talking on the phone, she says "He won't come down," (referring to Toshio) but her lips don't move.
Audio problem: After the detective listens to the message that Susan leaves for her brother on the answering machine, the detective pushes the button to locate the missing phone. The detective as well as another officer begin to follow the sound of the ringing phone which is very loud and audible near them. As they begin walking down the hallway towards the door the ringing becomes muffled and when he opens the door it becomes loud again.
Answer: I don't think she actually went back into the past, I think it was just the house showing her what happened, or at least a type of visual echo of what happened. After all, some pretty strange stuff was happening in that house.
Mad Ade