Bose A20 Aviation 2015-present Owner's guide - Page 15

Using the Headset Wearing and adjusting the headset Proper fit on your head is important both for comfort and optimal noise reduction performance. Here are a few guidelines: • Use the left (L) and right (R) markings above the earcups to orient the headset properly. R L 160º • The microphone is intended to rotate no more than 160° as shown above. Do not force the microphone beyond the intended rotation. • As you put the headset on, lightly grasp each earcup and adjust it so its cushion is completely over your ear. You should feel an even, gentle pressure all around each ear. • Adjust the headband so it rests gently on top of your head. • Make your final adjustments with the headset powered on in a noisy environment. In very loud conditions, such as during takeoff, you may experience a brief reduction in Acoustic Noise Cancelling® as the headset compensates for a momentary pressure change. If the problem continues when the sound level returns to normal, see "Noise reduction" on page 30. If the problem persists, contact Bose Technical Support. Conditions related to fit A low rumbling sound or frequent, brief losses of Acoustic Noise Cancelling noise reduction may indicate an improper fit or blocked earcup ports. See "Headset earcup openings" on page 26 for instructions on removing blockages. During a long flight, you may feel a slight pressure point, which can be relieved by adjusting the headband position. Your experience with using the headset will help establish a sense of how it should sound and feel. English - 15