The gas turbine engine including, in serial flow communication, a compressor, a combustor, a turbine, and a fluid system fluidly connecting at least two components of the gas turbine engine, also includes a tunable resonator in fluid flow communication with the fluid system, the tunable resonator. The tunable resonator has a resonating volume that varies as a function of a volume of an inflatable member located inside the tunable resonator. The inflatable member having a means for varying the volume of the inflatable member, to thereby tune the resonating volume to a selected frequency of pressure fluctuations or acoustic waves within the fluid system.