When the sound quality mode is switched, the headset indicates the remaining battery charge by flashing the indicator in red first, and then in blue to indicate the sound quality mode. You can check the current sound quality mode by the number of flashes of the indicator (blue).

To check the current sound quality mode when the unit is turned on, hold the POWER button down and press the VOL+ or VOL- button within about 2 seconds (before the headset turns off). The current sound quality mode will be shown by the number of flashes of the indicator (blue).