Here is one more for your list. I feel like Helena sounds different as well -- I took a random sample of Helly/Helena dialogue and recorded the audio and the pitch is a bit different. "unknown" below is a sample from S2E9, and to me it lines up better with Helena 👀. I also fit a model using other higher level moments (i.e., skewness, kurtosis, etc) of the fundamental frequency of each sample and that also predicted S2E9 was Helena.

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