Buck52 has some good advice saying "take another test from the VA and maybe go take a state license Audiologist private test that use the VA Guidelines/Criteria...ask the audiologist to compare the results of the two test."
In addition, the VA is likely to call for a C&P exam whether or not you submit the results of a privately administered exam with your claim. To my knowledge, the 'Maryland CNC exam' are the only test results the VA accepts for hearing.
Many hearing aid dealers offer 'free test' promotions throughout the year - go for it but let the VA give the first test. Then, (with your audiologist's opinion) you can offer your test results to counter the VA's.
The VA can deny or issue a '0' percentage but cannot call for a third opinion. That would considered "Developing to Deny" and it holds true with all private exams.