Annie Sullivan comes to the Keller household from The Perkins' Institute for the Blind and is only partially sighted herself. In The Miracle Worker, the audience learns of the difference the institute has made to Annie who admits that she "crawled in here like a drowned rat" from a home for the destitute and orphans. She is haunted by thoughts of her brother Jimmie who died in the home and in Act I, the audience is introduced to Jimmie through Annie's thoughts. When Annie meets the Keller family and she learns of Helen's half-brother's name--James--the stage directions indicate that "the name stops her" and she mentions that her brother had the same name.
When Helen locks Annie in her room, Annie is haunted by voices as she remembers when she was in the home and her brother was still alive, although barely. The doctor in the home tells her that her brother is going to die but Annie blocks out the voice.
In Act II, after Annie's momentous struggle with Helen, trying to get her to behave and after, due to Annie's enormous capacity for patience, Helen folds her napkin, Annie is again haunted by voices. Her brother asks Annie if it "hurts to be dead" and the voices urge Annie never to tell anyone that she came from the home. When the family talk of the possibilities of putting Helen in an "asylum," Annie does not shield the Keller's from the reality of life in such a place. She tells the family how she and Jimmie used to play with rats because there were no toys and does not spare the Kellers any detail.
In Act III, Annie is still haunted by the remembrance of having promised to stay with her brother "forever and ever" but by the end, after Helen has learnt the secret of language and can begin to express herself, the voices disappear. Annie waits for them to come but she "hears only silence."