In most cases, there are two reasons that may cause issues with properly hearing the sound of your bone conduction headphones:

1. First, maybe you should just try to increase the volume. Bone conduction needs the volume to be a lot harder compared to classic headphones because the sound needs to pass along the jaw bones directly to your inner ear.
2. Secondly, it could be that the placement of the headphone ears is not correct. Try to move your bone conduction headphones bit by bit to find the optimal placement. In general, the headphone ears must be placed a few centimeters before the opening of your outer ear.

If you have any problems, we recommend that you consult the instructions or contact your manufacturer.