The usefulness of wideband absorbance in the diagnosis of otosclerosis

Predictive accuracy of wideband absorbance in children with large vestibular aqueduct syndrome: A single-center retrospective study

Objectives

This study aimed to assess the clinical significance of Wideband Absorbance (WBA) in children with Large Vestibular Aqueduct Syndrome (LVAS), which could potentially serve as diagnostic and predictive markers for LVAS in children.

Design

This was a single-center retrospective case-control study. Audiological measurements and Wideband Acoustic Immittance (WAI) were performed. Propensity score matching (PSM) was considered to treat group imbalance. The Receiver Operating Characteristic (ROC) curves and area under the ROC curve (AUC) were used to evaluate the sensitivity and specificity of WBA.

Study sample

Participants included 42 children with LVAS and 163 normal children aged 6 months -11 years recruited from clinical audiology settings between 2019 and 2021.

Results

The WBA at Tympanometric Peak Pressure (WBATPP) and Ambient Pressure (WBAA) in the LVAS group were significantly lower than those of the control group at 1259-2000 Hz but higher at 4000-6349 Hz (p < 0.05, power >0.8). The WBAA (1587 Hz) AUC value was 0.805, identifying a score ≤0.565 as indicative of a LVAS risk.

Conclusions

WBA holds promise in distinguishing LVAS from the normal condition and warrants further exploration as a tool to examine the influence of inner ear pressure on acoustic energy transmission in the middle ear.

Study on characteristics of wideband acoustic immittance in patients with Inner Ear Malformations

OBJECTIVE

To compare the differences in wideband absorbance and the resonance frequency (RF) between patients with inner ear malformations and normal control, and to explore the auditory diagnostic value of wideband acoustic immittance (WAI).

METHODS

A total of 38 patients (59 ears) with enlarged vestibular aqueduct (EVA), 13 patients (14 ears) with incomplete partition type I (IP-I) and 13 patients (26 ears) with incomplete partition type II (IP-II) were included. 50 normal control (100 ears). All subjects underwent WAI tests to compare the absorbance configuration and resonance frequency.

RESULTS

All the group showed lower absorbance at ambient pressure than at peak pressure in certain frequencies under 2000Hz. Under 1000Hz, the absorbance of EVA was higher than that of other groups. The average absorbance and highest absorbance of IP-I were the lowest(P＜0.05). However, IP-II and normal group had similarity on some characteristics. The three IEM groups mainly different at low and high frequencies, but not at medium frequencies. The highest absorbance of all the groups were appeared around 3000Hz. The RF of all the groups from low to high were EVA＜IP-II＜normal control＜IP-I, and the lowest was EVA(P＜0.05).

CONCLUSION

Inner ear malformations can affect energy absorbance and RF. WAI is sensitive and non-invasive to provide useful information about inner ear status and facilitate detection of ear pathology.

Implementation of Wideband Acoustic Immittance in Clinical Practice: Relationships among Audiologic and Otologic Findings

A number of studies have produced normative and developmental data and examples of wideband acoustic immittance (WAI) obtained in ears with pathologies and or dysfunction. However, incorporation of this tool into clinical audiology and otolaryngology practice has been slower than expected, potentially due to challenges with interpretation, integration into existing test batteries, and confidence in practical application. This article presents information aimed at helping clinicians increase their confidence in using this new tool by becoming more familiar and making connections with the ways that WAI outcomes both align with and add to standard immittance, audiometric and otologic diagnostic test outcomes. This article presents several case studies to demonstrate the use of WAI in realistic clinical settings. Each case presents a brief background, case history, audiologic/otologic findings, and initial recommendations, followed by a discussion on how the inclusion of WAI test outcomes aids in diagnostic decisions. The overall aim of this work is to identify the relationships among different diagnostic test outcomes, to demonstrate basic WAI interpretation principles, and encourage the reader to engage with this diagnostic tool in clinical practice.

Wideband Acoustic Absorbance in Otosclerosis: Does Stapedotomy Restore Normal Tympanic Cavity Function?*

Introduction Otosclerosis is characterized by the fixation of the stapes to the oval window, thereby impairing acoustic signal absorbance. A commonly used surgical technique for improving hearing in cases of otosclerosis is stapedotomy. However, it is unclear whether this surgery restores all the physical characteristics of the tympano-ossicular system.

Objective To evaluate the tympano-ossicular system in individuals with fenestral otosclerosis pre and poststapedotomy using wideband tympanometry.

Method A total of 47 individuals and 71 ears were assessed. The subjects were divided into three groups: presurgery otosclerosis; postsurgery; and a control group of normal-hearing adults. A handheld tympanometer with a wideband module (226–8,000 Hz) was used to take measurements at ambient pressure and under pressurized conditions. The level of statistical significance adopted was p ≤ 0.05.

Results Acoustic absorbance at 226 Hz was low for all groups. At frequencies in the range 630 to 5,040 Hz, each group had a characteristic absorbance curve, allowing them to be distinguished from one another. In the presurgery group, absorbance values were below normal levels, with energy absorbance below 10%. Low energy absorbance was most evident at 1,000 Hz in the presurgery group, but this was not observed in the postsurgery group. Although there was an improvement in hearing, the surgery failed to restore the tympano-ossicular system to normal.

Conclusion Wideband acoustic absorbance proved able to differentiate normal ears and otosclerotic ears pre and postsurgery, under both ambient pressure and pressurized conditions.