Wideband acoustic absorbance and resonance frequency measurements in Ménière’s disease – case series
Authors: Leszczyński Michał , Lachowska Magdalena , Jasińska-Nowacka Agnieszka , Niemczyk Kazimierz 
Published: February 2024

<b><br>Introduction:</b> Ménière’s disease (MD) is characterized by vertigo episodes accompanied by hearing loss, tinnitus and aural fulness. The diagnostic criteria remain based on the clinical presentation. Still, new diagnostic possibilities provide novel information regarding the pathogenesis of the disease and processes occurring in the inner ear.</br> <b><br>Aim:</b> The study presents preliminary results of changes in wideband acoustic absorbance and resonance frequency measurements concerning the degree of endolymphatic hydrops in magnetic resonance imaging (MR) in patients with defined Ménière’s disease (MD).</br> <b><br>Material and methods:</b> The wideband acoustic absorbance and resonance frequency results were subjected to detailed analysis. The analysis also included the results of classical tympanometry, pure-tone audiometry, speech audiometry, and contrast-enhanced MR imaging in the protocol for diagnosing endolymphatic hydrops. The results of measurements taken in the clinically symptomatic ears and the asymptomatic contralateral ears of the same patients were analyzed. The results of the conducted tests were evaluated concerning the degree of cochlear hydrops in the MR examination.</br> <b><br>Results:</b> In all patients, MR confirmed the presence of endolymphatic hydrops. Differences were observed in the results of wideband acoustic absorbance between the symptomatic ears and the clinically unaffected contralateral ears. An additional notch in the low-frequency range was visualized on the wideband acoustic absorbance graphs of ears with Ménière’s disease. In some patients, the contralateral side also had a similar notch with different parameters. Furthermore, differences were observed in the wideband acoustic absorbance curves between patients with I and II degrees of endolymphatic hydrops evaluated in the MR imaging. Paradoxically, however, in the group of patients with II degrees of cochlear hydrops, the differences between ears in the results of wideband acoustic absorbance were less pronounced than in the group of patients with stage I hydrops. A decrease in resonance frequency was observed in the ear with Ménière’s disease only in one out of four patients, while this value was higher in the symptomatic ear in the remaining three patients.</br> <b><br>Conclusions:</b> Despite the small group of presented patients, differences were observed in wideband acoustic absorbance and resonance frequency measurements between the ear with Ménière’s disease and the asymptomatic ear. These differences mainly concern absorbance values in the low-frequency range. Moreover, an interesting observation is that a decrease in resonance frequency is described in the literature for ears with definite Ménière’s disease, which is a characteristic of conditions that decrease the stiffness of the sound-transmitting apparatus. However, these observations are not confirmed by the results presented in our study. Due to the small number of patients, it is impossible to draw far-reaching conclusions from this observation. Further research is necessary to apply wideband acoustic absorbance and resonance frequency in diagnosing Ménière’s disease in a larger group of patients. Understanding the correlation between the results of modern audiological methods and the advancement of endolymphatic hydrops observed in MR adds to the knowledge of the pathophysiology of Ménière’s disease. The preliminary results seem very interesting in assessing the utility of wideband acoustic absorbance and resonance frequency measurements as additional tests that could assist in determining the severity of endolymphatic hydrops.</br>