Stereo to mono for one sided earpiece.

[KevanAwes]

The issue:
When listening to music on my phone and using earphones, I use only one side for better hearing for my soroundings.
This causes some of my music sound very off as half of the instruments are on the other side and I only hear the bass instruments.

The request:
Is it possible to add an option to mix the channels/stereo into mono and play the mono on both side?