About a month ago I witnessed something similar. I went to see the movie "Detroit", which involves some deeply intense scenarios. It was an afternoon showing, the theater was only a third full. During the height of the tension, someone in the theater could be overheard crying, and talking to themselves, then hollering at the characters in the scene to stop  what the actors were portraying and offering some moral alternative. Deep stuff.  I could not figure out if it was a man or women, the voice was too strained with emotion, nor at the end of the film was I able to pick out the person involved, sound absorbing walls can play tricks on direction of sound. First time I had ever witnessed that kind on intense reaction during a film. However, Detroit was a movie which created  an atmosphere of strong emotional reaction. Prove saying is true. " See a book, feel a movie."