Throughout Pericles, the play makes use of speechless pantomimes called dumbshows, usually in tandem with John Gower's intervention as a chorus. Dumbshows are a dramatic device in which characters act out action without speech. As such, they are usually accompanied by music or other sound effects. In Pericles, dumbshows are used to advance the plot without taking time out of the central performance. Despite their name, dumbshows can also be used to communicate poignant moments where speech might fail a particular character. When Pericles returns to Tarsus, for example, the revelation that Marina is dead (or so he thinks) is expressed through a dumbshow in which Pericles sees Marina's tomb and weeps.
By the time Shakespeare was writing the play, dumbshows were already a relic of an earlier dramatic age. In medieval drama, dumbshows were used most often in the English morality play, and they would feature personified versions of abstract virtues and vices that would spar with one another to emphasize the play's moral direction. While they were still somewhat in fashion by the sixteenth century, the seventeenth century saw the demise of the dumbshow, which tended to appear only in courtly masques.
In Pericles, the dumbshow is both a plot device and a nod toward Shakespeare's source material. It was, after all, a medieval text on which the play was based, and some critics interpret Pericles to be a mock-medieval drama. It is fitting, then, that the dumbshows usually appear during Gower's choric interludes, as he comes to represent the medieval era more generally.