HTC One Remix - Manual (Page 45)

Pick up to lower volume
In a business meeting or restaurant,
pick HTC One remix up when a call
comes in to lower the ring volume
automatically.
You can turn this feature on or off.
Go to Settings, tap Sound, and then
select or clear Quiet ring on pickup.
Increase ring volume automatically while phone is in your pocket
or bag
Pocket mode makes HTC One remix recognize
when your phone is in your bag or pocket and
raise the ring volume so that you can hear it in
noisy environments.
You can turn this feature on or off. Go to Settings,
tap Sound, and then select or clear Pocket mode.
Your first week with your new phone 45