Using wideband reflectance to measure the impedance of the middle ear

Withnell, Robert H.; Parent, Pierre; Jeng, Patricia S.; Allen, Jont B.

doi:10.1097/01.hj.0000361848.81466.97

Cited by 6 publications

(3 citation statements)

References 3 publications

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“…Recently, measurements of umbo velocity using laser-Doppler vibrometry (LDV) and wideband acoustic immittance ( WAI ) measured in ear canals over a wide frequency range have been shown to aid in the non-invasive diagnosis of conductive disorders with aerated middle ears, including ossicular fixation, disarticulation, and SCD (e.g. Rosowski et al, 2003; Whittemore et al, 2004; Feeney et al, 2003; Allen et al, 2005; Rosowski et al, 2008; Feeney et al, 2009; Shahnaz et al, 2009a; Shahnaz et al, 2009b; Withnell et al, 2009; Voss et al, 2012; Nakajima et al, 2012; Nakajima et al, 2013; Prieve et al, 2013; Merchant et al, 2015). Collectively, these studies demonstrate that broadband measurements of middle-ear mobility, including WAI, can aid in the non-invasive differential diagnosis of conductive pathologies.…”

Section: Introductionmentioning

confidence: 99%

Controlled exploration of the effects of conductive hearing loss on wideband acoustic immittance in human cadaveric preparations

Merchant

Rosowski

et al. 2016

Hearing Research

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Current clinical practice cannot distinguish, with any degree of certainty, the multiple pathologies that produce conductive hearing loss in patients with an intact tympanic membrane and a well-aerated middle ear without exploratory surgery. The lack of an effective non-surgical diagnostic procedure leads to unnecessary surgery and limits the accuracy of information available during pre-surgical consultations with the patient. A non-invasive measurement to determine the pathology responsible for a conductive hearing loss prior to surgery would be of great value. This work investigates the utility of wideband acoustic immittance (WAI), a non-invasive measure of middle-ear mobility, in the differential diagnosis of pathologies responsible for conductive hearing loss. We focus on determining whether power reflectance (PR), a derivative of WAI, is a possible solution to this problem. PR is a measure of the fraction of sound power reflected from the middle ear when a sound stimulus is presented to the ear canal. PR and other metrics of middle-ear performance (such as ossicular motion via laser Doppler vibrometry) were measured in well-controlled human temporal bone preparations with simulated pathologies. We report measurements before and after simulation of stapes fixation (n=8), malleus fixation (n=10), ossicular disarticulation (n=10), and superior canal dehiscence (n=8). Our results are consistent with the small set of previously published reflectance measurements made in temporal bones and patients. In this present study, these temporal bone experiments with different middle- and inner-ear pathologies were compared to the initial normal state by analyzing both WAI and ossicular motion, demonstrating that WAI can be a valuable tool in the diagnosis of conductive hearing loss.

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Section: Introductionmentioning

confidence: 99%

Controlled exploration of the effects of conductive hearing loss on wideband acoustic immittance in human cadaveric preparations

Merchant

Rosowski

et al. 2016

Hearing Research

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“…A qualitative assessment of abnormal WBA patterns allows for inferences about pathological changes to be made in relationship with the acoustic mechanics of the middle ear, for example, pathological changes in mass, stiffness, and frequency of resonance. Such qualitative assessment paradigms are presented in details in Withnell et al 29 and AlMakadma, Kei et al in this issue. For example, a pathology or dysfunction which introduces stiffness (e.g., negative middle ear pressure) would hypothetically result in decreased absorbance for low frequencies.…”

Section: Wideband Acoustic Immittance Measures and Clinical Assessmentsmentioning

confidence: 99%

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

et al. 2023

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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.

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“…24 Modeling of the middle ear as physical spring-mass-resistance mechanical system provides a theoretical basis for qualitative assessment and interpretation of absorbance pattern across frequencies. 3,25 According to such models, pathology-related changes in mass and/or stiffness are expected to result in differential changes in absorbance across frequencies and affect the frequency at which the main absorbance peak occurs. Consider a middle ear condition where mass is abnormally increased.…”

Section: Assessment Of Abnormal Sound Conduction In Pathologies Of Mi...mentioning

confidence: 99%

Fundamental Concepts for Assessment and Interpretation of Wideband Acoustic Immittance Measurements

et al. 2023

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Assessment of middle ear impedance using noninvasive electroacoustic measurements has undergone successive developments since its first clinical application in the 1940s, and gained widespread adoption since the 1970s in the form of 226-Hz tympanometry, and applications in multifrequency tympanometry. More recently, wideband acoustic immittance (WAI) is allowing unprecedented assessments of the middle ear acoustic mechanics thanks to the ability to record responses over a wide range of frequencies. The purpose of this article is to present fundamental concepts for the assessment and interpretation of wideband measures, including a review of acoustic impedance and its relation to the mass, stiffness, and resistance components of the middle ear. Additionally, an understanding of the middle ear transfer function reveals the relationship between impedance and middle-ear gain as a function of frequency. Wideband power absorbance, a WAI measure, quantifies the efficiency of sound conduction through the middle ear over a wide range of frequencies, and can serve as an analogous clinical measure to the transfer function. The interpretation of absorbance measures in ears with or without a conductive condition using absorbance measured at ambient pressure and pressurized conditions (wideband tympanometry) is described using clinical case examples. This article serves as an introduction to the fundamental principles of WAI measurements.

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Using wideband reflectance to measure the impedance of the middle ear

Cited by 6 publications

References 3 publications

Controlled exploration of the effects of conductive hearing loss on wideband acoustic immittance in human cadaveric preparations

Controlled exploration of the effects of conductive hearing loss on wideband acoustic immittance in human cadaveric preparations

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

Fundamental Concepts for Assessment and Interpretation of Wideband Acoustic Immittance Measurements

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