This issue was a prime consideration when creating this system.
The short answer: So long as you have some hearing ability in each ear, you will still be able to reap the benefits of the system.
Also, if your hearing is better in one ear than the other, you can always adjust the left/right stereo balance on your audio player to compensate by boosting the volume on one side or the other.
As part of our 3 Point Dynamic Entrainment Audio Process, we apply much more than just binaural brainwave entrainment methods to the program (which is the protocol which neccessitates stereo headphones). There are still two other entrainment methods that the brain picks up on, outside of the binaural signals. This means that even if your your left/right hearing is not even, there are still powerful entrainment layers that maintain the program's effectiveness.