You need a Microphone to beat this:
1: Wait a minute for the Clock to strike for Midnight.
2: Take ten steps and then stop for the first Babylaugh.
3: Plug in a Microphone, go near Lisa Haunting and make random Sounds into your Mic. That´s enought I was able to trigger the second Babylaugh with the Fan noise of my PC alone while standing near Lisa Haunting, doesn´t matter if she is in the Hallway, in the Mirror or outside the Window.
4: After the second Laugh your Flashlight will start to flicker: Don´t move!!! If you move you have to do everything all over again by just exiting the Loop. After a while you will hear the third and final Babylaugh.
5: The Phone will ring. Pick up the phone by zooming in on it. Than you are done here, just exit the Loop like usual.
Congratulations you have beaten this awesome P.T. Remake!!!