Barcode, all respect, but that sound... the repetition, nothing added, one word over and over - that's the sound of somebody in a very primal state of anguish and/or fear.
I have sadly had occasion to hear that sound in my life, and also to make it. It's the sound very small, very frightened, panicked children make. It's the sound I made when I came home to find my partner dead, almost the exact same sound in fact. It's the sound of a horrible trauma happening, and the mind of that person in its most primal instictive state, where words actually make very little sense and the repetition .. I don't know if I would say it's comforting? But it is NOT really a "voluntary" sound like normal speech, you're not thinking, you're purely reacting to something you cannot believe or control.
I hope that helps you gain another perspective on the sounds Warriena was making.
eta: And I wanted to add, she was only making that sound, over and over, while Tostee was audibly manhandling her out onto the balcony - and for the majority of the 70 seconds he was out there with her.
The moment he retreated toward the door, she started screaming "Let me go home". Ie, something happened to let her break free of that primal terror and form proper words, simple as they are. That event was Tostee leaving the balcony. I dunno what that says to anyone else, but I have a pretty clear picture of what that very very likely means.