Comparison of Ear-Canal Reflectance and Umbo Velocity in Patients With Conductive Hearing Loss: A Preliminary Study

Abstract

Objective The goal of the present study was to investigate the clinical utility of measurements of ear-canal reflectance (ECR) in a population of patients with conductive hearing loss in the presence of an intact, healthy tympanic membrane (TM) and an aerated middle ear. We also sought to compare the diagnostic accuracy of umbo velocity (VU) measurements and measurements of ECR in the same group of patients. Design This prospective study comprised 31 adult patients with conductive hearing loss, of which 14 had surgically-confirmed stapes fixation due to otosclerosis, 6 had surgically-confirmed ossicular discontinuity, and 11 had CT- and VEMP-confirmed superior semicircular canal dehiscence (SCD). Measurements on all 31 ears included pure-tone audiometry for 0.25 – 8 kHz, ECR for 0.2 – 6 kHz using the Mimosa Acoustics HearID system, and VU for 0.3 – 6 kHz using the HLV-1000 laser Doppler vibrometer (Polytec Inc). We analyzed power reflectance |ECR|2 as well as the absorbance level = 10×log10(1−|ECR|2). All measurements were made prior to any surgical intervention. The VU and ECR data were plotted against normative data obtained in a companion study of 58 strictly defined normal ears (Rosowski et al. 2011). Results Small increases in |ECR|2 at low-to-mid frequencies (400–1000 Hz) were observed in cases with stapes fixation, while narrow-band decreases were seen for both SCD and ossicular discontinuity. The SCD and ossicular discontinuity differed in that the SCD had smaller decreases at mid-frequency (~1000 Hz), while ossicular discontinuity had larger decreases at lower frequencies (500–800 Hz). SCD tended to have less air-bone gap at high frequencies (1–4 kHz) compared to stapes fixation and ossicular discontinuity. The |ECR|2 measurements, in conjunction with audiometry, could successfully separate 28 of the 31 cases into the three pathologies. By comparison, VU measurements, in conjunction with audiometry, could successfully separate various pathologies in 29 of 31 cases. Conclusions The combination of |ECR|2 with audiometry showed clinical utility in the differential diagnosis of conductive hearing loss in the presence of an intact TM and an aerated middle ear, and appears to be of similar sensitivity and specificity to measurements of VU plus audiometry. Additional research is needed to expand upon these promising preliminary results.

Investigation of middle ear anatomy and function with combined video otoscopy-phase sensitive OCT

“…Using the tympanometry, the audiologists can diagnose some middle ear diseases including otitis media, perforation of the TM and problems with the Eustachian tube [7,8]. However, tympanometry has limited sensitivity in detecting various middle ear diseases (i.e., many patients with middle ear diseases have normal tympanogram) [9,10].…”

Reflectance measurement validation using acoustic horns

“…Although the variability observed in normative data is smaller than the differences observed between these data and data from ears with middle-ear pathologies (e.g., Voss et al, 2012;Nakajima et al, 2012), the variability affects the diagnostic value of WAI, especially considering that the diagnosis of middle pathologies using absorbance, for example, is based on comparison of the shape of the absorbance functions in patient ears to a normative reference absorbance function. It is important to limit the contribution to this variability that is due to the measurement system.…”

“…Reflectance has been observed to be sensitive to abnormal middle-ear states such as (1) positive and negative pressure in the middle-ear cavity, (2) a fluid-filled middle ear, (3) malleus or stapes fixation, (4) incudostapedial-joint disarticulation, (5) tympanic-membrane perforations, and (6) superior semicircular canal dehiscence. Because of its sensitivity to these pathological conditions, reflectance has been suggested for clinical diagnosis of various middle-ear disorders (e.g., Voss et al, 2012;Nakajima et al, 2012;Rosowski et al, 2012;Merchant, 2014;Merchant et al, 2015). However, reflectance measurements made with different measurement systems and made in different research laboratories can be variable.…”

Comparison of Ear-Canal Reflectance and Umbo Velocity in Patients with Conductive Hearing Loss

“…Results [1,2] showed that small increases in |ECR| 2 at low-to-mid frequencies (400-1000 Hz) were found in patients with stapes fixation, and distinct narrow-band decreases were seen for patients with both SCD (notch around 1000 Hz) and ossicular discontinuity (larger notch at 600-800 Hz). SCD patients tended to have smaller air-bone gaps at high frequencies compared to patients with stapes fixation and ossicular discontinuity.…”

“…Thirtyone of these patients were confirmed to have CHL due to stapes fixation, ossicular discontinuity, or superior semicircular canal dehiscence (SCD). Confirmation of the etiology responsible for the CHL was made surgically for both ossicular pathologies, and using a combination of high-resolution computed tomography imaging and vestibular evoked myogenic potential for SCD.Results [1,2] showed that small increases in |ECR| 2 at low-to-mid frequencies (400-1000 Hz) were found in patients with stapes fixation, and distinct narrow-band decreases were seen for patients with both SCD (notch around 1000 Hz) and ossicular discontinuity (larger notch at 600-800 Hz). SCD patients tended to have smaller air-bone gaps at high frequencies compared to patients with stapes fixation and ossicular discontinuity.…”