A sound-attenuating heat exchanger, comprising: an aerodynamically shaped layer; a base; an intermediate layer extending at least partially between the aerodynamically shaped layer and the base; and a cooled fluid containment body; wherein: (i) the aerodynamically shaped layer defines an aerodynamically shaped surface, which is shaped to direct flow of a first fluid stream that includes a first fluid, an opposed intermediate layer-facing surface, which faces toward the intermediate layer, and a plurality of apertures; (ii) the intermediate layer defines a shaped layer-facing surface, which faces toward the aerodynamically shaped layer, and an opposed base-facing surface, which faces toward the base; (iii) the base defines a base surface, which faces toward the intermediate layer; (iv) the intermediate layer-facing surface of the aerodynamically shaped layer at least partially defines a sound-attenuating volume that is configured to be in fluid communication with the first fluid stream, via the plurality of apertures, and is configured to attenuate sound energy from the first fluid stream; (v) the base surface of the base at least partially defines an elongate cooling conduit that extends between a cooling conduit inlet and a cooling conduit outlet and is configured to receive a cooling stream, which includes the first fluid, in heat exchange relationship with the cooled fluid containment body; (vi) the sound-attenuating volume is distinct from the elongate cooling conduit and the intermediate layer at least partially fluidly isolates the sound-attenuating volume from the elongate cooling conduit; and (vii) the cooled fluid containment body at least partially defines a cooled fluid containment conduit that extends between a cooled fluid containment conduit inlet and a cooled fluid containment conduit outlet and is configured to receive a cooled stream that includes a second fluid. an aerodynamically shaped layer; a base; an intermediate layer extending at least partially between the aerodynamically shaped layer and the base; and a cooled fluid containment body; wherein: (i) the aerodynamically shaped layer defines an aerodynamically shaped surface, which is shaped to direct flow of a first fluid stream that includes a first fluid, an opposed intermediate layer-facing surface, which faces toward the intermediate layer, and a plurality of apertures; (ii) the intermediate layer defines a shaped layer-facing surface, which faces toward the aerodynamically shaped layer, and an opposed base-facing surface, which faces toward the base; (iii) the base defines a base surface, which faces toward the intermediate layer; (iv) the intermediate layer-facing surface of the aerodynamically shaped layer at least partially defines a sound-attenuating volume that is configured to be in fluid communication with the first fluid stream, via the plurality of apertures, and is configured to attenuate sound energy from the first fluid stream; (v) the base surface of the base at least partially defines an elongate cooling conduit that extends between a cooling conduit inlet and a cooling conduit outlet and is configured to receive a cooling stream, which includes the first fluid, in heat exchange relationship with the cooled fluid containment body; (vi) the sound-attenuating volume is distinct from the elongate cooling conduit and the intermediate layer at least partially fluidly isolates the sound-attenuating volume from the elongate cooling conduit; and (vii) the cooled fluid containment body at least partially defines a cooled fluid containment conduit that extends between a cooled fluid containment conduit inlet and a cooled fluid containment conduit outlet and is configured to receive a cooled stream that includes a second fluid. (i) the aerodynamically shaped layer defines an aerodynamically shaped surface, which is shaped to direct flow of a first fluid stream that includes a first fluid, an opposed intermediate layer-facing surface, which faces toward the intermediate layer, and a plurality of apertures; (ii) the intermediate layer defines a shaped layer-facing surface, which faces toward the aerodynamically shaped layer, and an opposed base-facing surface, which faces toward the base; (iii) the base defines a base surface, which faces toward the intermediate layer; (iv) the intermediate layer-facing surface of the aerodynamically shaped layer at least partially defines a sound-attenuating volume that is configured to be in fluid communication with the first fluid stream, via the plurality of apertures, and is configured to attenuate sound energy from the first fluid stream; (v) the base surface of the base at least partially defines an elongate cooling conduit that extends between a cooling conduit inlet and a cooling conduit outlet and is configured to receive a cooling stream, which includes the first fluid, in heat exchange relationship with the cooled fluid containment body; (vi) the sound-attenuating volume is distinct from the elongate cooling conduit and the intermediate layer at least partially fluidly isolates the sound-attenuating volume from the elongate cooling conduit; and (vii) the cooled fluid containment body at least partially defines a cooled fluid containment conduit that extends between a cooled fluid containment conduit inlet and a cooled fluid containment conduit outlet and is configured to receive a cooled stream that includes a second fluid.