The headgear comprises ear cups (100a, 100b, fig 1a) and an air outlet nozzle positioned in front of a wearer’s face (1300, fig 1). Each ear cup comprises a housing containing a filter assembly (1112, fig 3a) and a motor-driven impeller (1109, fig 3a) for creating an airflow through the filter assembly to an air outlet downstream from the filter assembly. The ear cup further comprises an acoustic driver (1105, fig 3a), an inner acoustic microphone or vibration sensor (1106, fig 3a) disposed within the housing and an outer acoustic microphone or vibration sensor (1108, fig 3a) sensor mounted to the housing. The ear cup includes active feedforward noise control circuitry that in a high speed motor state uses the signal provided by the inner sensor to operate the acoustic driver and in low speed motor state switches 419 to the signal provided by the outer feedforward sensor. A further microphone 1132 acts to provide a feedback error signal (fig 4a). Other microphone arrangements are described (figs 5 & 7).
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