Belkin 3.5 audio / lightning plug adapter issue.

Whenever I plug in the Belkin 3.5 audio / lightning adapter to my phone and use the 3.5 input for earphones, I receive a constant pulsing / tap like sound about every second. This happens regardless if I am plugged in to the additional lightning charge port on the adapter, or not. Is the adapter defective? Or can this be fixed? Or is this an unfortunate unresolvable issue? Looking forward to a response from support and/or other users. Thank you.