Why are there two power switches?

The switch on your left earcup is the power switch, turning on the headphones and enabling a Bluetooth connection (remember - they have to be turned on in order for your personalisation profile to be applied!).

Meanwhile, the switch on your right earcup turns on the active noise cancelling only - giving you the choice to enjoy the Bluetooth connection and personalisation of your A-01s without needing to also use active noise cancelling.