Sennheiser HD 4.40BT Handbuch Seite 18

Getting started
Disconnecting the headphones from your Bluetooth device
Deactivate Bluetooth on your smartphone.
X
The headphones are disconnected from the smartphone. The headphones
then search for other paired devices. If no device is found, you hear the voice
prompt "lost connection". The headphones go to idle mode.
Menu
Bluetooth on
Bluetooth off
› lost connection ‹
HD 4.40BT | 17