As a general rule, ear cushions should be replaced every six months or every 350 hours of use. They may need to be replaced more often if:
The headset is worn over a full beard or heavy whiskers
The headset is subjected to severe temperature extremes—such as would occur if you park your aircraft outside in severe cold or heat
Excess strain is placed on the cushions because of improper storage
Indications that the ear cushions need replacing include:
Flaking of the outer covering
Cuts or tears
Flattening of the cushion, reducing the effectiveness of the seal
Grasp the ear cushion skirt where it folds into the slot on the earcup
Properly position the replacement ear cushion against the earcup
Tuck an edge of the ear cushion skirt into the slot cushion flange. Be careful not to fold the skirt over
Work the remainder of the skirt into the slot completely around the earcup
Grasp the ear cushion and adjust its position to remove folds in the skirt and wrinkles in the cushion
The headband cushion is designed to give the maximum level of comfort to your headset. Bose recommends that you replace the cushion after regular care and maintenance fails to restore the wool pile to its original size and shape.
Note: Removing and attaching the headband cushion may be easier if a second person holds the headset open.