[idkfa]

Amazing, yes. But why does the Smithsonian feel it is necessary to edit the tape and sync the words Anne Sullivan is speaking with Helen’s mouth so it looks like she is speaking perfectly?

[PghBaldy]

It is poorly done. It makes it seem Helen's voice was not coming from her mouth. Very odd. Here is Helen, speaking some more, later, with Polly:

https://www.youtube.com/watch?v=8ch_H8pt9M8