Abstract: The present application provides a muffler-heat exchanger (15) for an engine exhaust. The muffler-heat exchanger comprises a chamber (16) having an inlet (17) and an outlet (18) arranged such that during use exhaust gases flow through from the inlet to the outlet through the chamber. The muffler-heat exchanger also has at least one heat exchange baffle (25) disposed in the chamber to recover heat energy from the exhaust gases during use. The at least one heat exchange baffle is configured to reflect acoustic waves in the exhaust gases towards the inlet to generate destructive interference and impede incoming acoustic waves at the inlet. The present application also provides an exhaust system and an engine system.