Describe symbolism in WASP by Steve Martin

Near the end of the play, Martin portrays Dad in a somewhat less ridiculous and scathing light than previously in the play. In this final scene, Dad, like Mom and Son before him, tries to summon voices, but he finds that his voices have abandoned him. This symbolizes his thorough immersion in the way of life he has chosen for himself, in which he has long given up yearning for anything different.