issue bluethoot os x 10.10.5

Hi,

Weird issue... I have a wireless headphone, samsung level over, which has been working fine with my macbook pro early 2011 for 2 years almost. Now, when I used it, it just works on one side: I just hear the right side of the headphone... It could be an issue with the headphone, but headphone still work fine with Iphone 5s...

Any idea how to resolve the issue?

Thanks!

Olivier