The Voices

In the Deaf West Version of the show, the Deaf and Hard of Hearing actors have an additional actor portraying their Voice. These performers dress in modern clothes and appear in the onstage band, as well. However, the Voice actors are not just musical accompaniment, as they interact with their Deaf/HoH counterpart, and—occasionally—other actors, while maintaining different personalities from their other half.

Voice of Wendla/Guitar: Voice of Wendla is always seen close to her other half. She has a very similar personality to her counterpart, but she is much more brave and mature, except when Melchior is involved. She is the only Voice to directly speak to another character: Melchior. When Wendla is taken away for her abortion, Voice of Wendla has to be dragged away by a doctor. The original actress to portray her, Katie Boeck, says that she sees the Voice of Wendla as an angel.

Voice of Moritz/Guitar: Voice of Moritz tends more to the original Broadway production than his Deaf counterpart, who is cool and collected for the majority of the show. Voice of Moritz is Moritz’s inner rockstar, and dresses the part. He’s wild, rambunctious, and could be considered an antagonist, as he is shown pulling Moritz away from Ilse when she tries to save him from killing himself. He has the distinction of being the only non-adult character to not sign “Heaven” in the opening number of the show. Like Voice of Wendla, he has a direct interaction with the protagonist Melchior. Before Moritz’s suicide, Voice of Moritz hands his counterpart a gun and nods, as if affirming that killing himself is the right decision, before walking away. He was originally played by Alex Boniello, who claimed to be Moritz’s inner thoughts.

Voice of Martha/Guitar: Voice of Martha is never seen alongside her other half. She often wanders around the top of the stage, disconnected from most of the action. This was done to show Martha’s disconnect from herself due to her abuse. Like Voice of Wendla, she portrays herself in a much more powerful and mature way than her deaf counterpart, and seems almost bitter. Her original actress, Kathryn Gallagher, has made no official statement on what Voice of Martha is to Martha.

Voice of Ernst/Piano: Voice of Ernst and Ernst have the closest relationship of any pair in the show. They are constantly holding hands and Ernst spends much of the show sitting on his Voice’s piano. Arguably the most innocent character in the show, he is initially uncomfortable and apprehensive about Hanschen’s advances on his counterpart, however, by the end of the second act, he appears to have fallen just as hard for the manipulative schoolboy. Despite this, his happiness is short-lived, as after Ernst and Hanschen kiss, Ernst abandons his Voice in favor of his new love, and willingly walks away from him with Hanschen, thus displaying the end of Ernst’s innocence. The original actor who portrayed Voice of Ernst, Daniel David Stewart, says that his character is both a manifestation of Ernst’s innocence, and his imaginary friend.

Voice of Otto/Bass: Voice of Otto, like Voice of Martha, is generally separated from his deaf counterpart. However, their separation is not great, and there is no underlying symbol of disconnect between the two. Most likely, it is due to the fact that Voice of Otto’s instrument for much of the show is a double bass, which makes mobility difficult. Voice of Otto is very cocky and headstrong—going so far as to jump into the audience and interact with theatergoers (usually young women) in a charismatic manner. His existence is acknowledged only by Hanschen, who refers to him as “Bobby Maler,” and is lusted over by him, as well. His original actor,Sean Grandillo, has made no comment on what Voice of Otto is to Otto.

From wikipedia. A million thanks to whoever wrote this!