Careful preoperative selection of patients is one of the most important aspects to avoid complications. First, accurate audiology is essential. Audiological studies can contain inaccuracies as a result of machine, human, or calibration error. The otolaryngologist can use tuning forks judiciously to efficiently check results of the audiology. The 256, 512, and 1024 tuning forks, used in conjunction, can determine the degree of conductive hearing loss. In this way, otolaryngologists can operate on patients who have conductive hearing loss, not nerve hearing loss, which naturally leads to better results.
The 256 tuning fork gives a negative result (positive is normal) if the air-bone gap is greater than 15 dB. The 512 tuning fork gives a negative result if the air-bone gap is greater than 25 dB. The 1024 tuning fork is negative if the air-bone gap is greater than 30 to 35 dB. Ideally, all three forks are used in conjunction. However, if only one of the forks can be used, it should be the 512 fork. The 256 fork can be less accurate because it tests low frequencies, which are the same as the ambient noise in an office. More importantly, the 256 fork gives a negative result if the air-bone gap is greater than only 15 dB. A 15 dB air-bone gap should never be an indication for a surgical procedure to improve hearing. Stapedectomy should be performed when the airbone gap is greater than 25 dB; therefore the 256 test alone indicates surgery more often than is optimal.
Published on: May 14, 2015 Pages: 1-9