Jamieson, Fausset and Brown on Jeremiah 51:55

55. great voice--Where once was the great din of a mighty city, there shall be the silence of death [Vatablus]. Or, the "great voice" of the revellers (Jr 51:38, 39; Is 22:2). Or, the voice of mighty boasting [Calvin], (compare Jr 51:53).

her waves--"when" her calamities shall cause her to give forth a widely different "voice," even such a one as the waves give that lash the shores (Jr 51:42) [Grotius]. Or, "when" is connected thus: "the great voice" in her, when her "waves," &c. (compare Jr 51:13). Calvin translates, "their waves," that is, the Medes bursting on her as impetuous waves; so Jr 51:42. But the parallel, "a great voice," belongs to her, therefore the wave-like "roar" of "their voice" ought also belong to her (compare Jr 51:54). The "great voice" of commercial din, boasting, and feasting, is "destroyed"; but in its stead there is the wave-like roar of her voice in her "destruction" (Jr 51:54).