Sony MDR-1RBT - Manual (Page 71)

Tips
You cannot adjust the volume when not talking.
Volume for a call and listening to music can be adjusted independently. Even if
you change the volume while playing back the music, the volume of a call does
not change.
To end a call
Press the button on the headset.
After use
1. Disconnect the BLUETOOTH connection using the smartphone or mobile
phone.
2. Press and hold the POWER button on the headset for about 2 seconds.
The indicator (blue) goes off, and the headset turns off.
Copyright 2012 Sony Corporation
71