(written from a Production point of view)
Marnie Mosiman (born 6 March 1951; age 65) is an actress who portrayed the Harmony in the Star Trek: The Next Generation second season episode "Loud As A Whisper" in 1988. Mosiman is married to Q-actor John de Lancie since 1984 and is the mother of Trek actors Keegan and Owen de Lancie. Mosiman also voiced the character of "Melony" in the opening and closing segments of the audiobook for I, Q, which was co-written by de Lancie and Peter David. De Lancie adapted the story for audio and read the majority of the audiobook. Together with her husband, Mosiman was interviewed on 27 August 1991 for the TNG Season 2 DVD special feature "Departmental Briefing Year Two: Memorable Missions" ("Loud As A Whisper").
Prior to her work on Star Trek, Mosiman appeared in episodes of Knot's Landing (1982, with J.D. Hall), Dallas (1983, with Susan Howard and John Beck), Hill Street Blues (1985, with James Sikking, Barbara Bosson, Brent Spiner, Barry Kivel, and Patti Tippo), and Remington Steele (1986, with Fran Bennett and Clyde Kusatsu).
Further work includes guest roles in episodes of ABC Afterschool Specials (1990, with Lycia Naff and Todd Bryant), The Bold and the Beautiful (1992-1993, with Schae Harrison), Beverly Hills, 90210 (1993), Picket Fences (1994, with Ray Walston, Leigh Taylor-Young, Bruce French, and Roy Brocksmith), Frasier (1996, with Kelsey Grammer and Vaughn Armstrong), Profiler (1999, with Cyril O'Reilly and Scott Lawrence), and the Ally McBeal episode "Seeing Green" in 1999 in which she portrayed Marcia Gallin, mother of her real life son Keegan de Lancie. This episode also features Renee Goldsberry and Holmes Osborne.
Mosiman's film work includes the drama Hero (1992, with Richard Riehle, Don Pugsley, Leslie Jordan, Peggy Roeder, and Jay Leggett), the television science fiction film Without Warning (1994, with Brian McNamara, Spencer Garrett, Gina Hecht, her husband, Marnie McPhail, John DeMita, Armand Schultz, and Jeff Coopwood), the television science fiction audio play The Lost World (1998, with Roxann Dawson, her husband, Armin Shimerman, Leonard Nimoy, Ethan Phillips, and Dwight Schultz), the comedy What Women Want (2000, with Kelly Cooper, Cristine Rose, Sierra Pecheur, and Drew Howerton), and the short comedy Burl's (2003, with Jerry Hardin, her husband, and her son Owen de Lancie).
Also trained as a voice actress, Mosiman can be heard in the English version of the Studio Ghibli animated film Princess Mononoke (1997, with Dwight Schultz, Pamela Adlon, and John Hostetter), the video game Titanic Explorer (1997, with Tony Jay, Alexander Siddig, Olivia d'Abo, Alan Shearman, and Michael Ensign), and the Spicy City episode "Love Is a Download (1997, with Michelle Phillips).