When in the cold outdoors, the audio suddenly sounds lower, and the touch sensor control panel malfunctions.

If there is a sudden temperature change, such as when going from a warm indoor setting to the cold outdoors, the touch sensor control panel may malfunction. 
When the touch sensor control panel malfunctions the following symptoms may occur:

• The headset may switch to Quick Attention Mode and the audio may sound lower.
• The track switches by itself.
• Touch sensors stop working.
• Touch sensors operate by themselves.

In such a case, turn off the unit, wait until the temperature settles, then turn it on again.
If you have completed all the steps and the issue is not resolved, service may be required.