Frasier (Kelsey Grammer) fears Maris is having an affair with her Bavarian fencing instructor. Niles: David Hyde Pierce. Gunnar: Brian Cousins. Marta: Irene Olga Lopez. Voice of Gretchen: Glenne Headley. Martin: John Mahoney. Roz: Peri Gilpin. Daphne: Jane Leeves.