Complex sentence: In addition, Kellerman has provided her voice to animated features and television shows since the late-1970's, initially as "the Seal" in the "The Mouse and His Child" (1977).
Split into simpler sentences: In addition, Kellerman has provided her voice to animated features and television shows since the late-1970's. Initially as "the Seal" in the animated feature film, "The Mouse and His Child" (1977).