A mobile power generation system includes a trailer, a gas turbine housed inside the trailer, an electrical generator coupled to the gas turbine to generate electricity, an exhaust silencer system configured to receive exhaust has from the gas turbine, and a noise attenuation assembly coupled to and in fluid communication with the exhaust silencer system. The exhaust silencer system may be attached to a front end of the trailer and may include a diffuser system, a lower exhaust elbow silencer coupled to and in fluid communication with the diffuser system, and an upper exhaust elbow in fluid communication with the lower exhaust elbow silencer and comprising an outlet. The noise attenuation assembly includes an exhaust silencer unit mounted to a top end of the trailer. The exhaust silencer unit includes an inlet in fluid communication with the outlet of the upper exhaust elbow of the exhaust silencer system.