A machine is provided having an engine system wherein at least one engine
system component with an acoustic reflective surface is surrounded by a
jacket configured to absorb sound from at least one sound producing
device of the engine system. The jacket includes a sound absorbing
material such as fibrous thermal insulation and an acoustic permeable
covering between the acoustic reflective surface and the engine
compartment of the machine. The acoustic permeable covering of the jacket
may comprise a micro-perforated skin, whereby acoustic energy from the at
least one sound producing device of the engine system can enter a volume
defined by the jacket wherein it is absorbed by the sound absorbing
material. A method of operating an engine system includes dissipating
engine sound within a jacket surrounding an engine system component, the
jacket including an acoustic permeable covering and a sound absorbing
material positioned within the covering. An exhaust aftertreatment
element may by thermally insulated with the jacket.