The Chofetz Chayim’s son wrote that whenever the Chofetz Chayim saw that someone was beginning to speak loshon hora at the Shabbos table, he would announce that it was time to sing zmiros (Shabbos songs) so as to interrupt them. ~ Michtevai Chofetz Chayim – Dugmah Midarkai Avi as quoted by R’ Zelig Pliskin