Plantronics Calisto User Manual page 66

DRAFT
Receiving calls using your headset
Press for 1 second
TIP: You can use the headset to answer a second incoming call; see
"Receiving a second incoming call" on page 18.
Adjusting call volume using your headset
TIP: For your comfort and health, always listen to calls at a moderate volume.
For complete safety information, see page 50.
Page 12
Press up or down to adjust call volume
when you are using your headset (do
not press inward).