Nokia MD-8 Manual Del Usuario página 7

ENGLISH
To connect the speakers to a compatible Nokia device that has the
Nokia 2.5-mm AV Connector, connect the appropriate adapter
(if supplied) to the device and the audio plug to the adapter.
To switch on the speakers, slide the power key to the right.
The white indicator light turns on. To switch off, slide the
power key to the left. The indicator light turns off.
To listen to music when the speakers are connected to a
compatible device, start the music playback on the device.
To set the volume, use the volume controls on your device.
If the sound level of the speakers becomes too low, change
the speaker batteries.