Wideband acoustic transfer functions predict middle‐ear effusion

Abstract

Objectives/Hypothesis Compare the accuracy of wideband acoustic transfer functions (WATFs) measured in the ear canal at ambient pressure to methods currently recommended by clinical guidelines for predicting middle-ear effusion (MEE). Study Design Cross-sectional validating diagnostic study among young children with and without MEE to investigate the ability of WATFs to predict MEE. Methods WATF measures were obtained in a MEE group of 44 children (53 ears, mean age 1.9 years) scheduled for middle-ear ventilation tube placement and a normal age-matched control group of 44 children (59 ears, mean age 1.8 years) with normal pneumatic otoscopic findings and no history of ear disease or middle-ear surgery. An otolaryngologist judged whether MEE was present or absent and rated tympanic-membrane (TM) mobility via pneumatic otoscopy. A likelihood-ratio classifier reduced WATF data (absorbance, admittance magnitude and phase) from 0.25 to 8 kHz to a single predictor of MEE status. Absorbance was compared to pneumatic otoscopy classifications of tympanic membrane (TM) mobility. Results Absorbance was reduced in ears with MEE compared to ears from the control group. Absorbance and admittance magnitude were the best single WATF predictors of MEE, but a predictor combining absorbance, admittance magnitude and phase was the most accurate. Absorbance varied systematically with TM mobility based on data from pneumatic otoscopy. Conclusions Results showed that absorbance is sensitive to middle-ear stiffness and MEE, and WATF predictions of MEE in young children are as accurate as that reported for methods recommended by the clinical guidelines.

Predictions of middle-ear and passive cochlear mechanics using a finite element model of the pediatric ear

“…The normal group in the Ellison et al (2012) study included 59 ears of 44 children with normal pneumatic otoscopic findings, and no history of ear disease or middle-ear surgery.…”

“…In Keefe et al (2012), one such group included 35 ears of 24 patients with a conductive hearing loss who were medically classified as having otitis media with effusion. In Ellison et al (2012), the other such group included 53 ears of 44 patients who were scheduled for myringotomy and tube placement, such that the EA test was performed within one hour of their surgery. Data were included in this group only if the physician conducting the surgery confirmed the presence of MEE at operation.…”

“…Except where noted below, the viscoelastic parameters of the middle-ear soft tissues in the normal ear were determined by the cross-calibration process (Sun et al, 2002) based on the EA measurements in young children with normal hearing Ellison et al, 2012). These soft tissues are listed in the left column of After the viscoelastic parameters of the normal ear were determined, the behavior of the FE model in MEE ear was further validated against measurement data from two clinical otitis media groups reported by Ellison et al (2012) and Keefe et al (2012).…”

“…These measures are used in research and clinical audiology with both adults and young children to differentiate between normal ears and ears with specific middle-ear disorders (Keefe et al, 1993;Feeney et al, 2003;Allen et al, 2005;Beers et al, 2010;Ellison et al, 2012;Hunter et al, 2013). EA is the fraction of incident energy absorbed by the ear at a probe inserted in a mid-canal location.…”

Assessment of Conductive Dysfunction: Wideband Acoustic Immittance

“…Energy reflectance measure has been shown to provide superior performance in prediction of conductive hearing loss [4] and help improve newborn hearing screening outcomes [5]. The measure could be useful in the diagnosis of middle ear pathologies, e.g., otitis media with effusion [6], otosclerosis [7], and negative middle ear pressure [8]. The energy reflectance or absorbance measurement can also be performed with air pressure varied in the ear canal, known as wideband tympanometry [9,10].…”