aptX Bluetooth Headphones (B&O H8) Drop Sound - Yosemite
They are working perfect with OS X Yosemite 10.10.2. After upgrading to  10.10.3 (beta or final) the problem that you described appear. The headphones are working perfect first time after adding to bluetooth list, but is not a solution to delete and add again.
Bang &amp; Olufsen post this to their website:

Can I connect my BeoPlay H8 headphones with my MAC/PC using Bluetooth?
In most cases BeoPlay H8 is able to connect to a PC/MAC with Bluetooth 4.0 and a A2DP Bluetooth profile, provided that the hardware and drivers of the computer are also compatible. However, the computer protocols in the market are inconsistent and we cannot guarantee that BeoPlay H8 is able to connect using Bluetooth to all PC/MACs.