How Do the Normal and Boost Modes of the Shift Work?

The difference between the volume modes is the volume interval they adjust with each click of the volume buttons. In Normal mode, each click of the volume buttons covers a larger volume interval than the default volume mode. Likewise, in Boost mode, each click of the volume button adjusts the volume more than in Normal mode. In essence, these different volume modes allow you to adjust the volume quicker, with less clicks required to reach minimum/maximum volume.

As a result, after adjusting the volume mode switch on the transmitter, there is no direct volume difference on the headphones. You need to adjust the volume on the headphone to hear the difference.