Implementation of objective audiometery among Suez Canal Authority workers

Mostafa K Madi, Mohammed Shabana, Lobna Hamed, Noha A Hosny, Hedayat El Fouly

Advanced Arab Academy of Audio-Vestibulogy Journal 2016 3(2):43-50

Background Verification of the hearing level in the malinger workers is a long-standing problem. Otolaryngologists and audiologists are often called upon to evaluate the auditory thresholds of workers who file claims for compensation as a result of noise-induced hearing loss. Although objective diagnostic methods tend to dominate modern medical science, behavioral pure-tone audiometry (PTA) remains the golden standard for identifying hearing threshold levels. A number of auditory-evoked potential techniques have been implemented for this purpose over the past three decades. The most widely used of these techniques has been the auditory brainstem response (ABR) and more recently another auditory-evoked potential, the auditory steady-state response (ASSR). We also used old techniques such as postauricular myogenic potential and late cortical-evoked potential P100 as an alternative technique for objective audiometry. Rationale Integration of different objective hearing tests is deficient in the literature on high-risk adult population. Objectives To implement an objective protocol for assessing hearing in adult patients and for those difficult to test by routine PTA in Suez Canal Authority. Materials and methods This study was designed as a case–control study to collect and analyze data from September 2012 to be finished on June 2014. Sixty adult patients divided into two groups: those suffering from normal hearing and those suffering from sensorineural hearing loss. All patients in this research were submitted to the following: full history taking and otologic examination; basic audiological evaluations (PTA, speech audiometry and immittacemetry); tone burst ABR recorded using 500, 1000, 2000, and 4000 Hz stimulus; and ASSR stimulus using carrier frequencies 500, 1000, 2000, and 4000 Hz; postauricular myogenic potential response using 1000 and 4000 Hz; and late cortical-evoked potential P100 using 1000, 2000, and 4000 Hz. Results In the normal hearing group, ASSR and ABR thresholds are closer to PTA thresholds than posterior auricular muscle (PAM) thresholds, the difference decrease with increasing frequency being closer at 4000 Hz than 500 Hz results. In the study group ASSR and ABR thresholds are approximated to PTA thresholds but still the ASSR thresholds are closer to PTA thresholds than ABR thresholds and PAM threshold but much higher in the case of P100. In the study group, ABR and ASSR thresholds show the best level of prediction of PTA thresholds. We found that the mean difference between all test and pure-tone thresholds had a tendency to be smaller with increasing frequency in both groups. However, the mean difference in the study group was statistically significantly lower than the control group. There are statistically significant positive correlation between PTA threshold and both ABR and ASSR threshold at all frequencies. A statistically significant correlation was found only at 1000 Hz in PAM test and a statistically significant correlation was found only at 1000 and 2000 Hz in P100 test. Conclusion ASSR is more accurate at higher frequencies, making ASSR more suitable in accessing auditory thresholds in patients with noise-induced hearing loss.

from #Audiology via ola Kala on Inoreader http://ift.tt/2nhibEw
via IFTTT