HMD XR21 user guide

If you have trouble hearing your phone ringing in noisy environments or calls are too loud, you can change the volume to your liking by using the volume keys on the side of your phone.

Do not connect to products that create an output signal, as this may damage the device. Do not connect any voltage source to the audio connector. If you connect an external device or headset, other than those approved for use with this device, to the audio connector, pay special attention to the volume levels.

You can increase the loudspeaker volume with the boost mode.

1. Press the volume up key until you reach the 100% volume level.
2. Press the volume up key again to switch on audio boost mode. You can only use audio boost mode with the loudspeaker.
3. To decrease the volume, press the volume down key.

1. Press a volume key to see the volume level bar.
2. Tap more_horiz.
3. Drag the slider on the volume level bars left or right.
4. Tap DONE.

1. Press a volume key.
2. Tap notifications_none.
3. Tap vibration to set your phone to vibrate only or tap notifications_off to set it to silent.