I have a friend who is a sound engineer. He told me that the noise canceling does not completely reduce the sound pressure the ear experiences. In fact, the sound pressure can increase while the audible sound is decreased. This can be your problem.

I suggest you try the yellow foam cylinders. Twist them tight and insert them to where you just barely can grab them. They will expand to fill the space and eliminate or reduce the ambient sounds nicely. You will still be able to hear near voices.

I have never heard of a surgery for PCS hearing sensitivities. The problem is not the ear. It is the filtering system in the brain that sorts out the important stimuli from the ambient stimuli. In PCS, this filter is easily damaged and over-whelmed. Preventing this over-stimulation will improve your recovery.