iPod Touch / Bluetooth Headphones - Battery Useage

Oblivion

I am intrigued about how my iPod Touch and Jabra Revo Bluetooth Headphones interact with regard to power usage.

The headphones don't seem to operate the volume control independently, despite having their own internal battery to drive them. If I increase the slider on the iPod the volume goes up in the headphones and when I use the headphone's own volume slider control, the slider goes up on the iPod screen. So it seems they are bound together volume-wise via the two-way Bluetooth signal.

Does this mean that at higher volume levels the iPod will be eating more battery even though it is not directly connected to the headphones? If they were a wired set of headphones driven directly by the iPod then the answer would obviously be yes. But in the case of Bluetooth, the headphones must surely be providing the driving force using its own battery, so does the iPod use the same amount of power simply to provide the Bluetooth signal irrespective of the volume setting, or will it use more power if the volume is increased? :huh:

AJXX

I think with the bluetooth output the iPod uses the same amount of power regardless of volume setting. However I assume bluetooth overall will drain the battery quicker than a wired headset.

Wired headphones built in to the iPod will likely go through an internal amp, thus having the volume louder uses more power - bluetooth devices don't need an amp as they have their own power supplies, thus this is bypassed.