Wideband Reflectance in Normal Caucasian and Chinese School-Aged Children and in Children with Otitis Media with Effusion

Wideband Tympanometry and Pressurized Otoacoustic Emissions in Children with Surgical Excision of Palatine and/or Pharyngeal Tonsils

Palatine and pharyngeal tonsil hypertrophy may lead to dysfunction of the auditory tube due to a propensity for infection, potentially giving rise to otitis media. This is a quantitative and longitudinal study, developed from 2019 to 2021, at the State University of Campinas (UNICAMP). The studied sample comprised 15 participants aged 5 to 12 years (mean 7.9 years), 12 male and 3 female, arranged into two groups: children diagnosed with pharyngeal and/or palatine tonsil hypertrophy who were candidates for surgery (G1), and children who were later evaluated after surgery (G2). As part of the test, an otoscopy and measurements of logoaudiometry, pure-tone threshold audiometry, wideband tympanometry (ambient and peak pressure), and otoacoustic emissions (TEOAEs and DPOAEs, both at ambient and peak pressure) were all performed. There were statistically significant differences between phases in pure-tone audiometry, in terms of 226 Hz tympanometry, wideband tympanometry in peak pressure conditions, in the amplitude measurement TEOAEs in both pressure conditions, in DPOAEs in ambient pressure conditions, and in the signal/noise measurement in both pressures in DPOAEs. Overall, it was found that hearing tests were different for subjects with palatine and pharyngeal tonsil hypertrophy compared to the post-surgical group.

Differential effects of mass-loading the eardrum and stiffening the middle ear on wideband absorbance

The current work investigated the effects of mass-loading the eardrum on wideband absorbance in humans. A non-invasive approach to mass-loading the eardrum was utilized in which water was placed on the eardrum via ear canal access. The mass-loaded absorbance was compared to absorbance measured for two alternative middle ear states: normal and stiffened. To stiffen the ear, subjects pressurized the middle ear through either exsufflation or insufflation concurrent with Eustachian tube opening. Mass-loading the eardrum was hypothesized to reduce high-frequency absorbance, whereas pressurizing the middle ear was hypothesized to reduce low- to mid-frequency absorbance. Discriminant linear analysis classification was performed to evaluate the utility of absorbance in differentiating between conditions. Water on the eardrum reduced absorbance over the 0.7- to 6-kHz frequency range and increased absorbance at frequencies below approximately 0.5 kHz; these changes approximated the pattern of changes reported in both hearing thresholds and stapes motion upon mass-loading the eardrum. Pressurizing the middle ear reduced the absorbance over the 0.125- to 4-kHz frequency range. Several classification models based on the absorbance in two- or three-frequency bands had accuracy exceeding 88%.

Wideband Absorbance Predicts the Severity of Conductive Hearing Loss in Children With Otitis Media With Effusion

OBJECTIVES

The objectives of the present study were to investigate the relationship between wideband absorbance (WBA) and air-bone gap (ABG) in children with a conductive hearing loss (CHL) due to otitis media with effusion (OME) and determine the accuracy of WBA to predict the magnitude of ABGs.

DESIGN

This was a prospective, cross-sectional study involving a control group of 170 healthy ears from 130 children (mean age 7.7 years) and a CHL cohort of 181 ears from 176 children (mean age 5.9 years) with OME. The CHL cohort was divided into three groups: CHL1, CHL2, and CHL3 defined by mean ABG (averaged across 0.5 to 4 kHz) of 16 to 25 dB, 26 to 35 dB, and 36 to 45 dB, respectively. WBA was measured at frequencies from 0.25 to 8 kHz at ambient pressure.

RESULTS

WBA was significantly reduced between 0.25 and 5 kHz for all CHL groups. The difference in WBA at 1 to 4 kHz between the control and CHL groups increased with increasing ABG. The predictive accuracy, as indicated by area under the receiver operating characteristic curve (AUROC) of WBA, increased with increasing ABG. The AUROC for WBA at 1.5 kHz was 0.86 for the CHL1, 0.91 for the CHL2, and 0.93 for the CHL3 group. The AUROCs for WBA averaged across 0.5 to 4 kHz were 0.88, 0.93, and 0.94 for the CHL1, CHL2, and CHL3 groups, respectively. Linear regression analyses showed significant negative correlations between WBA 0.5-4 k and ABG 0.5-4 k . The regression model (ABG 0.5-4 k = 31.83 - 24.08 × WBA 0.5-4 k ) showed that WBA 0.5-4 k predicted ABG 0.5-4 k with high accuracy. Comparison of predicted and actual WBA on a different group of subjects revealed that at an individual level, the model predicted ABG between 16 and 35 with greater precision.

CONCLUSIONS

There were significant strong correlations between WBA and ABG such that WBA decreased with increasing ABG. WBA demonstrated good discrimination accuracy with AUROC exceeding 0.88 for the 0.5 to 4 kHz and 1 to 4 kHz frequency bands. The WBA test holds promise for determining the severity of CHL in children with OME.

Development and Application of a Reference Interval Approach to Wideband Absorbance Norms Using U.S. Population Data for Ages 6 to 80+ Years

PURPOSE

U.S. national wideband absorbance (WBA) data for 17,446 ears included in the National Health and Nutrition Examination Surveys for 2015-2016 and 2017-2020 were analyzed to develop and apply normative reference intervals (RIs).

METHOD

Analyses used distribution-free medians and cumulative distribution functions (CDFs). Notable differences between medians were defined as those with non-overlapping 95% confidence intervals, and differences between CDFs were evaluated using Cohen's h effect size. Strict inclusion criteria identified "healthy ears" with 1,240 ears meeting all the inclusion criteria for the reference group. RIs, WBA values corresponding to the 2.5th and 97.5th percentiles for the reference group, were established. The established RIs were then applied to the full unscreened data set to determine the prevalence of WBA values outside the RIs.

RESULTS

WBA RIs were established for all 6- to 19-year-olds and for 20- to 69-year-olds separated into three groups: females, males, and non-Hispanic Asians. The differences among the CDFs underlying these RIs corresponded to small effect sizes. When a single RI, 0.40 < average WBA < 0.75, was applied to the full data set, about 6%-13% of ears fell outside the derived RIs. Logistic regression analyses found abnormal tympanometric results to be responsible for the extreme WBA values among the general population. Abnormal tympanometric results increased the odds of having WBA values outside the RI by ≥ 300%.

CONCLUSIONS

U.S. population data for healthy ears were used to establish RIs for WBA of about 0.40-0.75. About 6%-13% of Americans, 6-80+ years of age, had WBA values outside these RI limits.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24185745.

Use of Wideband Acoustic Immittance in Neonates and Infants

With widespread agreement on the importance of early identification of hearing loss, universal newborn hearing screening (UNHS) has become the standard of care in several countries. Despite advancements in screening technology, UNHS and early hearing detection and intervention programs continue to be burdened by high referral rates of false-positive cases due to temporary obstruction of sound in the outer/middle ear at birth. A sensitive adjunct test of middle ear at the time of screening would aid in the interpretation of screening outcomes, minimize unnecessary rescreens, and prioritize referral to diagnostic assessment for infants with permanent congenital hearing loss. Determination of middle ear status is also an important aspect of diagnostic assessment in infants. Standard single-frequency tympanometry used to determine middle ear status in infants is neither efficient nor accurate in newborns and young infants. A growing body of research has demonstrated the utility of wideband acoustic immittance (WAI) testing in both screening and diagnostic settings. Wideband power absorbance (WBA), a WAI measure, has been shown to be more sensitive than tympanometry in the assessment of outer/middle ear function in newborns. Furthermore, age-graded norms also support successful application of WBA in young infants. Despite its merits, uptake of this technology is low among pediatric audiologists and hearing screening health workers. This report describes normative data, methods for assessment and interpretation of WBA, test-retest variations, and other factors pertinent to clinical use of WAI in newborns and infants. Clinical cases illustrate the use of WAI testing in newborn and infant hearing assessment.

Wideband Acoustic Immittance in Children

As wideband absorbance (WBA) gains popularity, it is essential to understand the impact of different middle ear pathologies on the absorbance patterns as a function of frequency in children with various middle ear pathologies. More recently, the use of wideband tympanometry has enabled clinicians to conduct WBA at ambient pressure (WBA _amb ) as well as the pressurized mode (WBA _TPP ). This article reviews evidence for the ability of WBA measurements to accurately characterize the normal middle ear function across a wide range of frequencies and to aid in differential diagnosis of common middle ear disorders in children. Absorbance results in cases of otitis media with effusion, negative middle ear pressure, Eustachian tube malfunction, middle ear tumors, and pressure equalization tubes will be compared to age-appropriate normative data. Where applicable, WBA _amb as well as WBA _TPP will be reviewed in these conditions. The main objectives of this article are to identify, assess, and interpret WBA _amb and WBA _TPP outcomes from various middle ear conditions in children between the ages of 3 and 12 years.

Evaluation of age-related changes in middle-ear structures by wideband tympanometry

BACKGROUND

Presbycusis is bilateral sensorineural hearing loss associated with the progressive degeneration of cochlear and central auditory pathways with aging.

AIMS/OBJECTIVES

We aimed to reveal age-related changes in middle ear function by using wideband tympanometry (WBT).

MATERIALS AND METHODS

Fifty-eight patients diagnosed with presbycusis were compared to 52 audiologically healthy participants. WBT measurement was performed on both ears via wideband click stimulus with a tympanometer device using probe tone frequencies of 226-8000 Hz.

RESULTS

There were no statistically significant differences detected among the resonance frequencies or maximum absorbance ratios measured in both ears between groups (p > .05). The mean absorbance of the right and left ears at 4000 and 8000 Hz was statistically higher in the patient group than in the healthy controls (r = 0.038, 0.030; l = 0.015, 0.012). Moreover, mean compliance values were found to be significantly lower in the patient group than in the control group (r = 0.030 and l = 0.040).

CONCLUSION

The significant differences detected in compliance and absorbance values for high frequencies in presbycusis patients were remarkable. Thus, it has been shown that WBT yields an advantage compared to traditional tympanometry in the diagnosis and treatment of middle ear diseases.

Can Wideband Tympanometry Predict the Prognosis of Otitis Media With Effusion?

Background and Objectives

This study aims to evaluate the capacity of wideband tympanometry (WBT) in predicting the prognosis of otitis media with effusion (OME).

Subjects and Methods

Sixty-one ears with effusion and 30 healthy ears of children were enrolled. The patients were followed up monthly using WBT. After the completion of measurements, the ears were separated into four groups according to the duration of recovery; Group 1: Good prognosis (≤1-month, n=18), Group 2: Worse prognosis (>1-month, n=29), Group 3: Surgical (no recovery, n=14), and Group 4: Control (healthy ears, n=30). Tympanometric peak pressure (TPP), resonance frequency (RF), and absorbance levels were compared within and between the groups.

Results

The TPP and RF values of the study group were lower than those of the controls (p<0.001). The ears with OME had lower absorbance measures than the controls at all frequencies; the differences were significant at 250, 500, and 1,000 Hz (p<0.001). However, at 2,000 Hz, the absorbance levels of the ears with OME were similar with those of the control group only in the good prognosis group (p>0.05). The receiver-operating characteristic analysis revealed that absorbance measures over 0.237 and 0.311 at 1,000 Hz and 2,000 Hz, respectively, have sensitivities and specificities over 70% for prediction of good prognosis, and the calculated odd ratio for these measures were 6 (p<0.05).

Conclusions

WBT measurement is promising in predicting the recovery of OME in children.

Normative wideband acoustic immittance patterns for middle ear evaluation in dogs

The objective of this study was to investigate the clinical use of wideband acoustic immittance (WAI) reflectance for middle ear assessment in dogs. Otoscopy and brainstem auditory evoked response testing was performed on all dogs prior to the WAI assessment. Following calibration, dogs were comfortably restrained while the probe was placed into the ear canal to obtain recordings. Testing was repeated for replicability. Repeatable WAI reflectance patterns were observed in 24 dogs, characterized by low-reflectance resonant peaks at approximately 1500-1800 Hz and 3000-4000 Hz. Observed patterns suggest WAI may be a practical means of assessing middle ear function in dogs.

A deep learning approach for detecting otitis media from wideband tympanometry measurements

OBJECTIVE

In this study, we propose an automatic diagnostic algorithm for detecting otitis media based on wideband tympanometry measurements.

METHODS

We develop a convolutional neural network for classification of otitis media based on the analysis of the wideband tympanogram. Saliency maps are computed to gain insight into the decision process of the convolutional neural network. Finally, we attempt to distinguish between otitis media with effusion and acute otitis media, a clinical subclassification important for the choice of treatment.

RESULTS

The approach shows high performance on the overall otitis media detection with an accuracy of 92.6%. However, the approach is not able to distinguish between specific types of otitis media.

CONCLUSION

Out approach can detect otitis media with high accuracy and the wideband tympanogram holds more diagnostic information than the commonly used techniques wideband absorbance measurements and simple tympanograms.

SIGNIFICANCE

This study shows how advanced deep learning methods enable automatic diagnosis of otitis media based on wideband tympanometry measurements, which could become a valuable diagnostic tool.

Preserving Wideband Tympanometry Information With Artifact Mitigation

OBJECTIVE

Absorbance measured using wideband tympanometry (WBT) has been shown to be sensitive to changes in middle and inner ear mechanics, with potential to diagnose various mechanical ear pathologies. However, artifacts in absorbance due to measurement noise can obscure information related to pathologies and increase intermeasurement variability. Published reports frequently present absorbance that has undergone smoothing to minimize artifact; however, smoothing changes the true absorbance and can destroy important narrow-band characteristics such as peaks and notches at different frequencies. Because these characteristics can be unique to specific pathologies, preserving them is important for diagnostic purposes. Here, we identify the cause of artifacts in absorbance and develop a technique to mitigate artifacts while preserving the underlying WBT information.

DESIGN

A newly developed Research Platform for the Interacoustics Titan device allowed us to study raw microphone recordings and corresponding absorbances obtained by WBT measurements. We investigated WBT measurements from normal hearing ears and ears with middle and inner ear pathologies for the presence of artifact and noise. Furthermore, it was used to develop an artifact mitigation procedure and to evaluate its effectiveness in mitigating artifacts without distorting the true WBT information.

RESULTS

We observed various types of noise that can plague WBT measurements and that contribute to artifacts in computed absorbances, particularly intermittent low-frequency noise. We developed an artifact mitigation procedure that incorporates a high-pass filter and a Tukey window. This artifact mitigation resolved the artifacts from low-frequency noise while preserving characteristics in absorbance in both normal hearing ears and ears with pathology. Furthermore, the artifact mitigation reduced intermeasurement variability.

CONCLUSIONS

Unlike smoothing algorithms used in the past, our artifact mitigation specifically removes artifacts caused by noise. It does not change frequency response characteristics, such as narrow-band peaks and notches in absorbance at different frequencies that can be important for diagnosis. Also, by reducing intermeasurement variability, the artifact mitigation can improve the test-retest reliability of these measurements.

Wideband Tympanometry Findings in School-aged Children: Effects of Age, Gender, Ear Laterality, and Ethnicity

OBJECTIVES

Wideband tympanometry (WBT) measures middle-ear function across a range of frequencies (250 to 8000 Hz) while the ear-canal pressure is varied from +200 to -300 daPa. WBT is a suitable test to evaluate middle-ear function in children, but there is a lack of age-, ear-, gender-, or ethnicity-specific data throughout the literature. The purpose of this study was to investigate the effects of age, ear laterality, gender, and ethnicity on the WBT data retrieved from children aged 4 to 13 years determined to have normal middle-ear function.

DESIGN

Data were collected cross-sectionally from 924 children aged 4 to 13 years who passed a test battery consisting of 226-Hz tympanometry, ipsilateral acoustic stapedial reflexes, and pure-tone screening, and without significant history of middle-ear dysfunction. Participants were grouped according to their age: 4 to 6 years, 7 to 9 years, 10 to 13 years. Wideband absorbance values were extracted at 0 daPa (WBA0) and tympanometric peak pressure (WBATPP).

RESULTS

The effects of age, frequency, and pressure (WBA0 versus WBATPP) were statistically significant. There were significant differences between WBA0 and WBATPP for all age groups such that WBA0 had lower absorbance at low frequencies (250 to 1600 Hz) and greater absorbance at mid to high frequencies (2500 to 8000 Hz). Statistically significant effects of age were present for WBA0 and WBATPP such that absorbance generally increased with age from 250 to 1250 Hz and decreased with age from 2000 to 5000 Hz. There were no significant main effects of gender, ear, or ethnicity.

CONCLUSIONS

Gender-, ear-, and ethnicity-specific clinical WBA0 and WBATPP norms are not required for diagnostic purposes; however, age-specific norms may be necessary. Age-related changes in middle-ear function were observed across WBA0 and WBATPP. The data presented in this study are a suitable clinical reference for evaluating the outer- and middle-ear function of school-aged children.

The sensitivity and specificity of wideband absorbance measure in identifying pathologic middle ears in adults living with HIV

BACKGROUND

Limited research exists on the sensitivity and specificity of wideband acoustic immittance (WAI) in adults living with human immunodeficiency virus (HIV). This study forms part of the bigger study titled 'wideband acoustic immittance in adults living with HIV'.

OBJECTIVES

To determine the sensitivity and specificity of the wideband absorbance measure at tympanic peak pressure (TPP), as a screening tool for detecting middle ear pathologies in adults living with HIV.

METHOD

A prospective nonexperimental study comprising 99 adults living with HIV was performed. All participants underwent a basic audiological test battery which included case history, video otoscopy, tympanometry, wideband absorbance at TPP and pure tone audiometry. Middle ear pathologies were established by two otorhinolaryngologists using asynchronous video otoscopic images analysis. The outcomes of the otorhinolaryngologists served as the gold standard against which the wideband absorbance at TPP and tympanometry were measured. The receiver operating characteristics (ROC) curve was calculated.

RESULTS

ROC revealed the sensitivity of wideband absorbance at TPP to be higher in low to mid frequencies, but significantly lower in frequencies above 971.53 Hz. The sensitivity of tympanometry was lower. However, there was no difference between the specificity of wideband absorbance at TPP and tympanometry, indicating that when there are no pathologies, tympanometry is equally accurate.

CONCLUSION

The current findings reveal that wideband absorbance at TPP can distinguish middle ear pathologies better than the tympanometry. Incorporating wideband absorbance at TPP in clinical practice may improve early identification and intervention of middle ear pathologies.

The influence of otitis media with effusion on middle-ear impedance estimated from wideband acoustic immittance measurements

The goal of this work was to estimate the middle-ear input impedance ( Z_me) from wideband acoustic immittance (WAI) measures and determine whether Z_me improves the clinical utility of WAI. The data used in this study were from a previously reported set of WAI measurements in ears with otitis media with effusion [OME; Merchant, Al-Salim, Tempero, Fitzpatrick, and Neely (2021). Ear Hear., published online]. Ears with OME were grouped based on effusion volume, which was confirmed during tube surgery. Z_me was estimated from the measured ear-canal impedance. An electrical-analog model of ear-canal acoustics and middle-ear mechanics was used to model the ear canal and Z_me. The model results fit the measured responses well for all conditions. A regression approach was used to classify the responses of different variable types to effusion volume groups and determine the specificity and sensitivity of the binary classifications. The Z_me magnitude increased with increasing effusion volume. The area under the receiver operating characteristic curve (AUC) was compared for binary decisions of the OME categories. The Z_me estimate resulted in a clinically meaningful improvement in the AUC for distinguishing healthy ears from ears with OME. Overall, these results suggest that Z_me estimation may provide useful information of potential clinical value to improve the diagnostic utility of WAI measurements for OME.

Clustering upper airway physicals, otitis media with effusion and auditory functions in children

OBJECTIVE

Adenoid hypertrophy (AH) has been identified as a cause of otitis media with effusion (OME), which is the most common cause of childhood hearing loss. Indeed, there may be other upper airway-related predisposing factors such as, location of the adenoid, accompanying tonsillar hypertrophy (TH) and nasal septal deviation (NSD) for the development of OME. In this study, we aimed to evaluate the associations between the upper airway physicals and OME with auditory functions.

METHODS

Eighty-six ears of 43 children, aged 3-11 years were included in this prospective clinical study. Findings of otolaryngologic examinations were noted. Data of pure tone audiometry (PTA), traditional tympanometry (TT) and wideband tympanometry (WBT) parameters were collected. Cluster analysis was performed to the following variables: age, sex; the adenoid choana percentage (ACP), the presences of adenoid around torus tubarius (AATT), TH, NSD and OME; peak pressure (PP) values on TT, resonance frequencies (RF) on WBT, ambient pressure absorbance ratios (APAR) and PTA hearing thresholds.

RESULTS

Two groups of ears revealed by clustering; cluster-1 (n = 46) and cluster-2 (n = 40), at the similarity level of 0.662. The presences of AH, AATT, OME and the medians of ACP, PP, RF, WBT APARs at all frequencies except 5656 Hz and 8000 Hz, all PTA thresholds were significantly different between two clusters (p < 0.05). The lower WBT APARs and higher PTA thresholds were associated with higher levels of ACP and higher frequencies of the presence of AATT and OME in cluster-1.

CONCLUSION

There are associations between AH, AATT and OME together with decline in hearing and SEA. Whereas, TH and NSD are not related to the formation of clusters and they are insignificant factors.

Effect of Cochlear Implantation on Vestibular Evoked Myogenic Potentials and Wideband Acoustic Immittance

OBJECTIVES

The objective of this study was to determine if absent air conduction stimuli vestibular evoked myogenic potential (VEMP) responses found in ears after cochlear implantation can be the result of alterations in peripheral auditory mechanics rather than vestibular loss. Peripheral mechanical changes were investigated by comparing the response rates of air and bone conduction VEMPs as well as by measuring and evaluating wideband acoustic immittance (WAI) responses in ears with cochlear implants and normal-hearing control ears. The hypothesis was that the presence of a cochlear implant can lead to an air-bone gap, causing absent air conduction stimuli VEMP responses, but present bone conduction vibration VEMP responses (indicating normal vestibular function), with changes in WAI as compared with ears with normal hearing. Further hypotheses were that subsets of ears with cochlear implants would (a) have present VEMP responses to both stimuli, indicating normal vestibular function and either normal or near-normal WAI, or (b) have absent VEMP responses to both stimuli, regardless of WAI, due to true vestibular loss.

DESIGN

Twenty-seven ears with cochlear implants (age range 7 to 31) and 10 ears with normal hearing (age range 7 to 31) were included in the study. All ears completed otoscopy, audiometric testing, 226 Hz tympanometry, WAI measures (absorbance), air conduction stimuli cervical and ocular VEMP testing through insert earphones, and bone conduction vibration cervical and ocular VEMP testing with a mini-shaker. Comparisons of VEMP responses to air and bone conduction stimuli, as well as absorbance responses between ears with normal hearing and ears with cochlear implants, were completed.

RESULTS

All ears with normal hearing demonstrated 100% present VEMP response rates for both stimuli. Ears with cochlear implants had higher response rates to bone conduction vibration compared with air conduction stimuli for both cervical and ocular VEMPs; however, this was only significant for ocular VEMPs. Ears with cochlear implants demonstrated reduced low-frequency absorbance (500 to 1200 Hz) as compared with ears with normal hearing. To further analyze absorbance, ears with cochlear implants were placed into subgroups based on their cervical and ocular VEMP response patterns. These groups were (1) present air conduction stimuli response, present bone conduction vibration response, (2) absent air conduction stimuli response, present bone conduction vibration response, and (3) absent air conduction stimuli response, absent bone conduction vibration response. For both cervical and ocular VEMPs, the group with absent air conduction stimuli responses and present bone conduction vibration responses demonstrated the largest decrease in low-frequency absorbance as compared with the ears with normal hearing.

CONCLUSIONS

Bone conduction VEMP response rates were increased compared with air-conduction VEMP response rates in ears with cochlear implants. Ears with cochlear implants also demonstrate changes in low-frequency absorbance consistent with a stiffer system. This effect was largest for ears that had absent air conduction but present bone conduction VEMPs. These findings suggest that this group, in particular, has a mechanical change that could lead to an air-bone gap, thus, abolishing the air conduction VEMP response due to an alteration in mechanics and not a true vestibular loss. Clinical considerations include using bone conduction vibration VEMPs and WAI for preoperative and postoperative testing in patients undergoing cochlear implantation.

Wideband Acoustic Immittance in Cochlear Implant Recipients: Reflectance and Stapedial Reflexes

OBJECTIVES

to characterize differences in wideband power reflectance for ears with and without cochlear implants (CIs), to describe electrically evoked stapedial reflex (eSR)-induced changes in reflectance, and to evaluate the benefit of a broadband probe for reflex threshold determination for CI recipients. It was hypothesized that reflectance patterns in ears with CIs would be consistent with increased middle ear stiffness and that reflex thresholds measured with a broadband probe would be lower compared with thresholds obtained with a single-frequency probe.

DESIGN

Eleven CI recipients participated in both wideband reflectance and eSR testing. Ipsilateral reflexes were measured with three probes: a broadband chirp (swept from 200 to 8000 Hz), a 226 Hz tone, and a 678 Hz tone. Wideband reflectance measures acquired from 28 adults without CIs and with normal middle ear function served as a normative data set for comparison.

RESULTS

Considering the group data, average reflectance was significantly greater for ears with CIs across 250 to 891 Hz and 4238 to 4490 Hz compared with the normative data set, although individual reflectance curves were variable. Some CI recipients also had low 226 Hz admittance, which contributed to the group finding, considering the control group had clinically normal 226 Hz admittance by design. Electrically evoked stapedial reflexes were measurable in nine of 14 ears (64.3%) and in 24 of 46 electrodes (52.5%) tested. Reflex-induced changes in reflectance patterns were unique to the participant/ear, but similar across activators (electrodes) within a given ear. In addition, reflectance values at or above 1000 Hz were affected most by activating the stapedial reflex, even in ears with clinically normal 226 Hz admittance. This is a higher-frequency range than has been reported for acoustically evoked reflex-induced reflectance changes and is consistent with increased middle ear stiffness at rest. Electrically evoked reflexes could be measured more often with the 678 Hz or the broadband probe compared with the 226 Hz probe tone. Although reflex thresholds were lower with the broadband probe compared with the 678 Hz probe in 16 of 24 conditions, this was not a statistically significant finding (Wilcoxon signed-rank test; p = 0.072).

CONCLUSIONS

The applications of wideband acoustic immittance measurements (reflectance and reflexes) should also be considered for ears with CIs. Further work is needed to describe changes across time in ears with CIs to more fully understand the reflectance pattern indicating increased middle ear stiffness and to optimize measuring eSRs with a broadband probe.

Assessing the Effect of Middle Ear Effusions on Wideband Acoustic Immittance Using Optical Coherence Tomography

Wideband acoustic immittance (WAI) noninvasively assesses middle ear function by measuring the sound conduction over a range of audible frequencies. Although several studies have shown the potential of WAI for detecting the presence of middle ear effusions (MEEs), determining the effects of MEE type and amount on WAI in vivo has been challenging due to the anatomical location of middle ear cavity. The purpose of this study is to correlate WAI measurements with physical characteristics of the middle ear and MEEs determined by optical coherence tomography (OCT), a noninvasive optical imaging technique.

Analysing wideband absorbance immittance in normal and ears with otitis media with effusion using machine learning

Wideband Absorbance Immittance (WAI) has been available for more than a decade, however its clinical use still faces the challenges of limited understanding and poor interpretation of WAI results. This study aimed to develop Machine Learning (ML) tools to identify the WAI absorbance characteristics across different frequency-pressure regions in the normal middle ear and ears with otitis media with effusion (OME) to enable diagnosis of middle ear conditions automatically. Data analysis included pre-processing of the WAI data, statistical analysis and classification model development, and key regions extraction from the 2D frequency-pressure WAI images. The experimental results show that ML tools appear to hold great potential for the automated diagnosis of middle ear diseases from WAI data. The identified key regions in the WAI provide guidance to practitioners to better understand and interpret WAI data and offer the prospect of quick and accurate diagnostic decisions.

Improving the Differential Diagnosis of Otitis Media With Effusion Using Wideband Acoustic Immittance

OBJECTIVES

The objective of this work is to determine whether there is a systematic effect of middle ear effusion volume on wideband acoustic immittance in children with surgically confirmed otitis media with effusion.

DESIGN

Wideband acoustic immittance was measured in 49 ears from children (9 months to 11 years) who had a diagnosis of otitis media with effusion and compared to 14 ears from children (10 months to 10 years) without a recent history of otitis media. For children with otitis media with effusion, wideband acoustic immittance testing took place in the child's preoperative waiting room before surgical placement of tympanostomy tubes. Testing was completed in a pressurized condition (wideband tympanometry) for all ears as well as in an ambient condition in a subset of ears. Intraoperative findings regarding effusion volume were reported by the surgeons immediately before tube placement and confirmed following myringotomy. This classified the volume of effusion as compared to middle ear volume categorically as either full, partial, or clear of effusion. The type of wideband acoustic immittance explored in this work was absorbance. Absorbance responses were grouped based on effusion volume into one of four groups: full effusions, partial effusions, ears clear of effusion at the time of surgery, and normal control ears. Standard tympanometry was also completed on all ears.

RESULTS

Absorbance is systematically reduced as the volume of the middle ear effusion increases. This reduction is present at most frequencies but is greatest in the frequency range from 1 to 5 kHz. A multivariate logistic regression approach was utilized to classify ears based on effusion volume. The regression approach classified ears as effusion present (full and partial ears) or absent (clear ears and normal control ears) with 100% accuracy, ears with effusion present as either partial or full with 100% accuracy, and ears without effusion as either normal control ears or ears clear of effusion with 75% accuracy. Regression performance was also explored when the dataset was split into a training set (70% of the data) and a validation test set (30% of the data) to simulate how this approach would perform on unseen data in a clinical setting. Accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve are reported. Overall, this approach demonstrates high sensitivity and specificity for classifying ears as effusion being present or absent and as present effusions being full or partial with areas under the curve ranging from 1 to 0.944. Despite the lack of effusion present in both clear ears and normal control ears, this approach was able to distinguish between these ears, but with a more moderate sensitivity and specificity. No systematic effect of effusion volume was found on standard tympanometry.

CONCLUSIONS

Wideband acoustic immittance, and more specifically, absorbance, is a strong and sensitive indicator of the volume of a middle ear effusion in children with otitis media with effusion.

Wideband Absorbance in Ears with Retraction Pockets and Cholesteatomas: A Preliminary Study

OBJECTIVES

The objective of this study was to describe wideband absorbance (WBA) findings in patients with cholesteatomas and retraction pockets (RPs).

DESIGN

In this prospective study, tympanometry, audiometry, and wideband tympanometry (WBT) were performed on 27 ears with an RP (eight with epitympanic RP and 19 ears with mesotympanic RP), 39 ears with a cholesteatoma (23 ears with epitympanic and 16 ears with mesotympanic cholesteatomas [MCs]), and 49 healthy ears serving as controls.

RESULTS

Mean WBA at ambient pressure (WBA_amb) of both experimental groups was reduced significantly between 0.8 and 5 kHz relative to the control group. The difference between mean WBA_amb and mean WBA at tympanometric peak pressure (WBA_TPP) was greater for the RP (0.12-0.16 between 0.5 and 1.5 kHz) than for the cholesteatoma group (0.03-0.11 between 0.6 and 3 kHz). Mean WBA_amb of both epitympanic RP (ERP) and epitympanic cholesteatoma (EC) subgroups was significantly lower than that of the control group. Mean WBA_TPP of the ERP subgroup attained normal levels as per the control group, while mean WBA_TPP of EC subgroup was significantly lower than that of the control group at 0.8 to 1.5 kHz and 4 to 5 kHz. In contrast, both mesotympanic RP and MC subgroups demonstrated similar mean WBA_amb and WBA_TPP values. No significant differences in WBA_amb and WBA_TPP results between the RP and cholesteatomas groups were observed. Receiver operating characteristic (ROC) analyses indicated that the area under the ROC curve for distinguishing between the RP and cholesteatomas groups ranged from 0.44 to 0.60, indicating low accuracy in separating the two groups.

CONCLUSION

While it is not possible to distinguish between the RP and cholesteatomas groups based on the WBA_amb and WBA_TPP results, it is potentially feasible to differentiate between the EC and ERP conditions. Further study using a large clinical sample is recommended to determine the sensitivity and specificity of the WBA test to identify the EC and ERP conditions.

Characteristics of the wideband absorbance of acoustic energy in children (3-7 years old) with otitis media with effusion

OBJECTIVE

This study aimed to investigate the characteristics of the wideband absorbance (WBA) of acoustic energy in children (3-7 years old) with otitis media with effusion (OME) under environmental ear-canal air pressure and tympanometric peak pressure and to determine the diagnostic value of the acoustic energy absorption rate (AR) in OME at different frequencies.

METHODS

A total of 178 children aged 3-7 years were enrolled in the study between April and October 2018. They were separated into two groups: those with middle ear effusion were placed in the OME group (n = 80; 136 ears), while those without OME (n = 98; 182 ears) were placed in the control group. A WBA test was performed on the children in both groups under environmental ear-canal pressure and tympanometric peak pressure to analyze the changing characteristics of the AR value within the 0.226-8 kHz range.

RESULTS

Under ambient ear-canal air pressure, the AR of the OME group in each frequency band was significantly lower than that of the control group (P < 0.01). Under tympanometric peak pressure, the AR of the OME group in most frequencies was also significantly lower than those of the control group (P < 0.01) except in the 2-2.5 kHz range. The area under the receiver operating characteristic curve (AUROC) was highest at 0.47-1.03 kHz: 0.96 and 0.94 at ambient ear-canal pressure and tympanometric peak pressure, respectively. Of the single frequency points, those at 0.65, 0.67, 0.69, 0.71, and 0.73 kHz had a higher AUROC value (0.96-0.97) under both ambient ear-canal air pressure and tympanometric peak pressure. The difference in the AUROC values of the two pressure conditions was not statistically significant (P < 0.01).

CONCLUSION

Overall, WBA is an effective method of diagnosing OME in children. The frequency band with the most predictive value of AR for OME is 0.47-1.03 kHz. Middle ear effusion can be quickly identified by observing AR values in this frequency range, which provides a diagnostic basis for OME.

Assessment of Pediatric Middle Ear Effusions With Wideband Tympanometry

OBJECTIVE

To determine if wideband tympanometry (WBT) can differentiate types of middle ear effusion (MEE): serous, mucoid, and purulent.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary care children's hospital.

METHODS

Children who met American Academy of Otolaryngology-Head and Neck Surgery's guidelines for ventilation tube insertion had WBT after anesthesia induction but before tympanotomy. MEE was categorized into 1 of 4 comparison groups: serous effusion, mucoid effusion, purulent effusion, or no effusion. WBT measurements were averaged to 16 one-third octave frequency bands, and comparison of the absorbance patterns for each MEE type was performed through a linear mixed effects model.

RESULTS

A total of 118 children (211 ears) were included: 47 females (39.8%) and 71 males (60.2%). The mean age was 2.73 years (95% CI, 2.25-3.22); mean weight, 14.35 kg (95% CI, 12.85-15.85); and mean Z score, 1.13 (95% CI, -0.64 to 2.33). Effusions included 61 mucoid (28.9%), 30 purulent (14.2%), and 14 serous (6.6%), with 106 (50.2%) having no effusion. No significant differences were found for sex, race, age, weight, or Z score among the 4 types of effusion (P < .05). WBT showed a significant difference in median absorption among the effusion groups (P < .001), with a medium effect size of 0.35.

CONCLUSIONS

WBT has potential use to differentiate types of MEE and should be studied further as a tool for investigating how the natural history and management of serous and mucoid effusions may differ.

Study on wideband tympanometry and absorbance within a Danish cohort of normal hearing adults

PURPOSE

The objectives of this study was to present wideband tympanometry (WBT) data and absorbance with normal hearing and normal middle ear status.

METHODS

Data were collected in 99 adult Caucasians with normal hearing and middle ear status. Energy absorbance was measured with an Interacoustics^© Titan^® using clicks for 1/24-octave frequency-intervals (0.226-8 kHz) with the ear canal air pressure alternated using a descending pressure sweep from + 250 to - 350 daPa.

RESULTS

From the wideband energy absorbance tympanograms, the mean energy absorbance tympanogram, wideband averaged tympanogram and parameters such as ear canal volume, middle ear pressure and resonance frequency were determined.

CONCLUSIONS

This study established a dataset containing descriptive analysis of wideband tympanograms and its derived parameters in Caucasian adults with normal hearing and normal middle ear conditions. The data presented in this study may serve as a future reference for WBT studies with Caucasian adults.

Inner ear pressure evaluation using wideband tympanometry in children with Large Vestibular Aqueduct Syndrome (LVAS): A pilot study

OBJECTIVE

To investigate middle ear function in children with Large Vestibular Aqueduct Syndrome (LVAS) to explore the feasibility of measuring inner ear pressure using Wideband tympanometry (WBT).

METHODS

13 young children with LVAS were recruited. WBT and other audiological measurements i.e., Auditory Steady State Response (ASSR), Auditory Brain Stem Response (ABR), and Distorted Product Otoacoustic Emissions (DPOAE) were performed. Absorbance under ambient and peak pressure were compared with normative data, and analyzed using a one sample t-test.

RESULTS

Average absorbance in children with LVAS was significantly lower than normative data under ambient pressure at 1000, 1189, 1296, 2000 Hz and 4000 Hz. Absorbance under peak pressure was also significantly lower at 707, 794, 917, 1000, 1189, 1297, 1498 and 2000 Hz. However, absorbance was higher than standard values above 4000 Hz under ambient and peak pressure. It was also higher under ambient pressure at frequencies below 500 Hz.

CONCLUSION

The special characteristics of middle ear function found in children with Large Vestibular Aqueduct Syndrome (LVAS) indicate that WBT offers a sensitive and non-invasive method to evaluate inner ear pressure indirectly.

Effect of Negative Middle Ear Pressure and Compensated Pressure on Wideband Absorbance and Otoacoustic Emissions in Children

Objective This study investigated pressurized transient evoked otoacoustic emission (TEOAE) responses and wideband absorbance (WBA) in healthy ears and ears with negative middle ear pressure (NMEP). Method In this cross-sectional study, TEOAE amplitude, signal-to-noise ratio, and WBA were measured at ambient and tympanometric peak pressure (TPP) in 36 ears from 25 subjects with healthy ears (age range: 3.1-13.0 years) and 88 ears from 76 patients with NMEP (age range: 2.0-13.1 years), divided into 3 groups based on NMEP (Group 1 with TPP between -101 and -200 daPa, Group 2 with TPP between -201 and -300 daPa, and Group 3 with TPP between -301 and -400 daPa). Results Mean TEOAE amplitude, signal-to-noise ratio, and WBA were increased at TPP relative to that measured at ambient pressure between 0.8 and 1.5 kHz. Further decrease in TPP beyond -300 daPa did not result in further increases in the mean TEOAE or WBA at TPP. The correlation between TEOAE and WBA was dependent on the frequency, pressure conditions, and subject group. There was no difference in pass rates between the 2 pressure conditions for the control group, while the 3 NMEP groups demonstrated an improvement in pass rates at TPP. With pressurization, the false alarm rate for TEOAE due to NMEP was reduced by 17.8% for NMEP Group 1, 29.2% for NMEP Group 2, and 15.8% for NMEP Group 3. Conclusion Results demonstrated the feasibility and clinical benefits of measuring TEOAE and WBA under pressurized conditions. Pressurized TEOAE and WBA should be used for assessment of ears with NMEP in hearing screening programs to reduce false alarm rates.

Diagnosing Conductive Dysfunction in Infants Using Wideband Acoustic Immittance: Validation and Development of Predictive Models

Purpose The aims of this study were (a) to validate the wideband acoustic immittance (WAI) model developed by Myers et al. (2018a) in a new sample of neonates and (b) to develop a prediction model for diagnosing middle ear dysfunction in infants aged 6-18 months using wideband absorbance, controlling for the effect of age. Method Tympanometry, distortion product otoacoustic emissions, and WAI were measured in 124 neonates and longitudinally in 357 infants at 6, 12, and 18 months of age. Results of tympanometry and distortion product otoacoustic emissions were used to assess middle ear function of each infant. For the first study, results from the neonates were applied to the diagnostic WAI model developed by Myers et al. (2018a). For the second study, a prediction model was developed using results from the 6- to 18-month-old infants. Results from 1 ear of infants in each age group (6, 12, and 18 months) were used to develop the model. The amount of bias (overfitting) was estimated with bootstrap resampling and by applying the model to the opposite ears (the test sample). Performance was assessed using measures of discrimination (c-index) and calibration (calibration curves). Results For the validation study, the Myers et al. (2018a) model was well calibrated and had a c-index of 0.837 when applied to a new sample of neonates. Although this was lower than the apparent performance c-index of 0.876 reported by Myers et al., it was close to the bias-corrected estimate of 0.845. The model developed for 6- to 18-month-old infants had satisfactory calibration and apparent, bias-corrected, and test sample c-index of 0.884, 0.867, and 0.887, respectively. Conclusions The validated and developed models may be clinically useful, and further research validating, updating, and assessing the clinical impact of the models is warranted.

Wideband tympanometry findings in inner ear malformations

OBJECTIVE

The deficits in the cochlea which is at the one end of the ear sound transfer system, may effect middle ear functions. Wideband typanometry (WBT) is frequently used to evaluate these transfer functions which play a crucial role in setting the impedance matching between the external ear and the cochlea. To this end, the aim of this study was to investigate the ear transfer functions in inner ear malformations via WBT, and to question whether these functions change depending on the types of inner ear malformation.

METHODS

This prospective case-control study was conducted in a university hospital. One hundered-fifty-seven ears (aged 3-37 years) under the groups of cochlear hypoplasia, incomplete partition I, incomplete partition II, cochlear aplasia and complete labyrinthine aplasia were evaluated. In the control group, 30 ears with normal hearing were enrolled and WBT was carried out. Tympanometric peak pressure, equivalent middle ear volume, static admittance, tympanogram width, resonance frequency, average wideband tympanometry and absorbance measurements were analyzed.

RESULTS

The inner ear malformation groups demonstrated statistically significant differences than the control group and from each other in terms of traditional tympanometric parameters and WBT test parameters (p<0.05). The most remarkable difference was between the group of complete labyrinthine aplasia and the control group, most probably because of complete labyrinthine aplasia's structural effects. However, on some parameters, incomplete partition II and the control group showed similarities. In absorbance measurements, there was significant difference between all patient groups and the control group, especially at high frequencies (p<0.05). The largest difference was between the control group and the group of complete labyrinthine aplasia which has revealed the lowest absorbance values (p<0.05). In averaged-wideband tympanogram analysis, all patient groups obtained a lower amplitude peak than the control group; complete labyrinthine aplasia group had the flattest peaked amplitude, while the incomplete partition II group had a near-normal curve.

CONCLUSION

The results of the study revealed the distinctive effects of inner ear malformations in middle ear transfer functions. It is concluded that the absence of inner ear structures causes negative effects on energy absorbance and the other transfer functions of the middle ear. WBT may provide additional information on diagnosis of patients with inner ear malformations.

Diagnosing Middle Ear Dysfunction in 10- to 16-Month-Old Infants Using Wideband Absorbance: An Ordinal Prediction Model

Purpose The aim of this study was to develop an ordinal prediction model for diagnosing middle ear dysfunction in 10- to 16-month-old infants using wideband absorbance. Method Wideband absorbance, tympanometry, and distortion product otoacoustic emissions were measured in 358 ears of 186 infants aged 10-16 months (M _age = 12 months). An ordinal reference standard (normal, mild, and severe middle ear dysfunction) was created from the tympanometry and distortion product otoacoustic emission results. Absorbance from 1000 to 5657 Hz was used to model the probability of middle ear dysfunction with ordinal logistic regression. Model performance was evaluated using measures of discrimination (c-index) and calibration (calibration curves). Performance measures were adjusted for overfitting (bias) using bootstrap resampling. Probabilistic and simplified methods for interpreting the model are presented. The probabilistic method displays the probability of ≥ mild and ≥ severe middle ear dysfunction, and the simplified method presents the condition with the highest probability as the most likely diagnosis (normal, mild, or severe middle ear dysfunction). Results The c-index of the fitted model was 0.919 (0.914 after correction for bias), and calibration was satisfactory for both the mild and severe middle ear conditions. The model performed well for the probabilistic method of interpretation, and the simplified (most likely diagnosis) method was accurate for normal and severe cases but diagnosed some cases with mild middle ear dysfunction as normal. Conclusions The model may be clinically useful, and either the probabilistic or simplified paradigm of interpretation could be applied, depending on the context. In situations where the main goal is to identify severe middle ear dysfunction and ease of interpretation is highly valued, the simplified interpretation may be preferable (e.g., in a screening clinic that may not be concerned about missing some mild cases). In a diagnostic clinical environment, however, it may be beneficial to use the probabilistic method of interpretation.

A Study of Wideband Energy Reflectance in Patients with Otosclerosis: Data from a Chinese Population

Objective(s)

The purpose of this study was to explore the effectiveness of wideband acoustic immittance (WAI) in the diagnosis of otosclerosis by comparing the differences in the energy reflectance (ER) of WAI between patients with otosclerosis and age- and gender-matched normal hearing controls in the Chinese population.

Methods

Twenty surgically confirmed otosclerotic ears were included in the otosclerotic group. The ER of WAI at ambient and peak pressures, resonance frequency, and 226-Hz tympanogram were collected prior to surgery using a Titan hearing test platform (Interacoustics A/S, Middelfart, Denmark). All diagnoses of otosclerosis in the tested ear were confirmed by surgery after the measurements. Thirteen normal adults (26 ears) who were age- and gender-matched with the otosclerotic patients were included as the control group.

Results

At peak pressure, the ERs of otosclerotic patients were higher than those of the control group for frequencies less than 4,000Hz and were lower for frequencies greater than 4,000Hz. In addition, within the analyzed frequencies, the differences observed at 2,520Hz was statistically significant (p<0.05/16=0.003, Bonferroni corrected). At ambient pressure, the differences observed at 1,260 and 6,350Hz were statistically significant (p<0.05/16=0.003, Bonferroni corrected). Although the differences between the otosclerotic and control groups exhibited similar trends to those in studies implemented in Caucasian populations, the norms in the present study in the control group were different from those in the Caucasian populations, suggesting racial differences in WAI test results. Regarding the middle ear resonance frequency, no significant difference was observed between the two groups (P>0.05).

Conclusion

WAI can provide valuable information for the diagnosis of otosclerosis in the Chinese population. Norms and diagnostic criteria corresponding to the patient's racial group are necessary to improve the efficiency of WAI in the diagnosis of otosclerosis.

Longitudinal Development of Wideband Absorbance and Admittance Through Infancy

Purpose The aim of this article was to study the normal longitudinal development of wideband absorbance and admittance measures through infancy. Method Two hundred one infants who passed the newborn hearing screen (automated auditory brainstem response) were tested at birth and then followed up at approximately 6, 12, and 18 months of age. Most infants were of either White (86%) or Asian (11%) descent. At each test session, infants passed tympanometry and distortion product otoacoustic emission tests. High-frequency (1000-Hz) tympanometry was used at birth and 6 months of age, and low-frequency (226-Hz) tympanometry was used at 12 and 18 months of age. Wideband pressure reflectance was also measured at each session and analyzed in terms of absorbance, admittance at the probe tip, and admittance normalized for differences in ear canal area. Multilevel hierarchical models were fitted to the absorbance and admittance data to investigate for effects of age, ear side, gender, ethnicity, and frequency. Results There were considerable age effects on wideband absorbance and admittance measurements over the first 18 months of life. The most dramatic changes occurred between birth and 6 months of age, and there were significant differences between all age groups in the 3000- to 4000-Hz region. There were significant ethnicity effects that were substantial for certain combinations of ethnicity, age, and frequency (e.g., absorbance at 6000 Hz at 12 months of age). Conclusion There are large developmental effects on wideband absorbance and admittance measures through infancy. For absorbance, we recommend separate reference data be used at birth, 6 months of age, and 12-18 months of age. For admittance (both normalized and at the probe tip), we advise using separate normative regions for each age group (neonates and 6, 12, and 18 months).

Normative Wideband Acoustic Immittance Measurements in Caucasian and Aboriginal Children

Purpose The aims of this study were to develop normative data for wideband acoustic immittance (WAI) measures in Caucasian and Australian Aboriginal children and compare absorbance measured at 0 daPa (WBA₀) and tympanometric peak pressure (TPP; WBA_TPP) between the 2 groups of children. Additional WAI measures included resonance frequency, equivalent ear canal volume, TPP, admittance magnitude (YM), and phase angle (YA). Method A total of 171 ears from 171 Caucasian children and 87 ears from 87 Aboriginal children who passed a test battery consisting of 226-Hz tympanometry, transient evoked otoacoustic emissions, and pure tone audiometry were included in the study. WAI measures were obtained under pressurized conditions using wideband tympanometry. Data for WBA₀, WBA_TPP, YM, and YA were averaged in one-third octave frequencies from 0.25 to 8 kHz. Results There was no significant ear effect on all of the 7 measures for both groups of children. Similarly, there was no significant gender effect on all measures except for WBA_TPP in Aboriginal children. Aboriginal boys had significantly higher WBA_TPP than girls at 1.5 and 2 kHz. A significant effect of ethnicity was also noted for WBA_TPP at 3, 4, and 8 kHz, with Caucasian children demonstrating higher WBA_TPP than Aboriginal children. However, the effect size and observed power of the analyses were small for both effects. Conclusion This study developed normative data for 7 WAI measures, namely, WBA₀, WBA_TPP, TPP, Veq, RF, YM, and YA, for Caucasian and Aboriginal children. In view of the high similarity of the normative data between Caucasian and Aboriginal children, it was concluded that separate ethnic-specific norms are not required for diagnostic purposes.

A Longitudinal Analysis of Pressurized Wideband Absorbance Measures in Healthy Young Infants

OBJECTIVES

Wideband absorbance (WBA) is an emerging technology to evaluate the conductive pathway (outer and middle ear) in young infants. While a wealth of research has been devoted to measuring WBA at ambient pressure, few studies have investigated the use of pressurized WBA with this population. The purpose of this study was to investigate the effect of age on WBA measured under pressurized conditions in healthy infants from 0 to 6 months of age.

DESIGN

Forty-four full-term healthy neonates (17 males and 27 females) participated in a longitudinal study. The neonates were assessed at 1-month intervals from 0 to 6 months of age using high-frequency tympanometry, acoustic stapedial reflex, distortion product otoacoustic emissions, and pressurized WBA. The values of WBA at tympanometric peak pressure (TPP) and 0 daPa across the frequencies from 0.25 to 8 kHz were analyzed as a function of age.

RESULTS

A linear mixed model analysis, applied to the data, revealed significantly different WBA patterns among the age groups. In general, WBA measured at TPP and 0 daPa decreased at low frequencies (<0.4 kHz) and increased at high frequencies (2 to 5and 8 kHz) with age. Specifically, WBA measured at TPP and 0 daPa in 3- to 6-month-olds was significantly different from that of 0- to 2-month-olds at low (0.25 to 0.31 kHz) and high (2 to 5 and 8 kHz) frequencies. However, there were no significant differences between WBA measured at TPP and 0 daPa for infants from 3 to 6 months of age.

CONCLUSIONS

The present study provided clear evidence of maturation of the outer and middle ear system in healthy infants from birth to 6 months. Therefore, age-specific normative data of pressurized WBA are warranted.

Normative wideband absorbance measures in healthy neonates in Korea: A preliminary study

INTRODUCTION

The usefulness of wideband absorbance (WBA) in newborns is well-demonstrated. However, it is still not clear whether there might be a difference according to ethnicity with respect to ambient WBA; therefore, further investigation is necessary to evaluate ethnic-specific normative WBA values in newborns.

METHODS

Twenty-one newborns (41 ears) were recruited from the well-baby nursery at a tertiary referral center. All newborn infants who were born at 38 weeks' to 41 weeks' gestation with a normal birth weight (range: 2.5-4.5 kg) and who passed a newborn hearing screening test with distortion product otoacoustic emissions were enrolled. Ambient absorbance values were measured on frequencies ranging from 226 Hz to 6300 Hz (i.e., 250 Hz, 315 Hz, 400 Hz, 500 Hz, 620 Hz, 800 Hz, 1000 Hz, 1250 Hz, 1600 Hz, 2000 Hz, 2500 Hz, 3150 Hz, 4000 Hz, 5000 Hz, and 6300 Hz). The results of median absorbance were compared with the WBA values of Caucasian infants and Korean adults.

RESULTS

The gestational age of the study group was 38 weeks ± 6.67 days. In a gender comparison, absorbance of female neonate was significantly higher at 3150 Hz, 4000 Hz, and 5000 Hz than in male. Based on the test frequencies, the medians of the Korean infant WBA values and Caucasian infants are significantly different from one another, except at 1600 Hz, 3150 Hz, and 4000 Hz. The results of a median absorbance comparison between Korean infant and adults WBA values showed that the medians of the two studies were significantly different except at 1250 Hz.

CONCLUSION

We analyzed the normative WBA values measured at ambient pressures in Korean newborns. The comparative analysis between the normative values of two different ethnic groups may infer a possible difference in the normative WBA values. The absorbance from Korean infant ears is substantially different from that from adult's ears. A large-scale study is required to establish normative WBA values to be used for the screening of outer and middle ear status in newborns.

Diagnosing Middle Ear Pathology in 6- to 9-Month-Old Infants Using Wideband Absorbance: A Risk Prediction Model

PURPOSE

The aim of this study was to develop a risk prediction model for detecting middle ear pathology in 6- to 9-month-old infants using wideband absorbance measures.

METHOD

Two hundred forty-nine infants aged 23-39 weeks (Mdn = 28 weeks) participated in the study. Distortion product otoacoustic emissions and high-frequency tympanometry were tested in both ears of each infant to assess middle ear function. Wideband absorbance was measured at ambient pressure in each participant from 226 to 8000 Hz. Absorbance results from 1 ear of each infant were used to predict middle ear dysfunction, using logistic regression. To develop a model likely to generalize to new infants, the number of variables was reduced using principal component analysis, and a penalty was applied when fitting the model. The model was validated using the opposite ears and with bootstrap resampling. Model performance was evaluated through measures of discrimination and calibration. Discrimination was assessed with the area under the receiver operating characteristic curve (AUC); and calibration, with calibration curves, which plotted actual against predicted probabilities.

RESULTS

AUC of the fitted model was 0.887. The model validated adequately when applied to the opposite ears (AUC = 0.852) and with bootstrap resampling (AUC = 0.874). Calibration was satisfactory, with high agreement between predictions and observed results.

CONCLUSIONS

The risk prediction model had accurate discrimination and satisfactory calibration. Validation results indicate that it may generalize well to new infants. The model could potentially be used in diagnostic and screening settings. In the context of screening, probabilities provide an intuitive and flexible mechanism for setting the referral threshold that is sensitive to the costs associated with true and false-positive outcomes. In a diagnostic setting, predictions could be used to supplement visual inspection of absorbance for individualized diagnoses. Further research assessing the performance and impact of the model in these contexts is warranted.

Differentiating among conductive hearing loss conditions with wideband tympanometry

OBJECTIVE

This study was aimed to investigate whether wideband tympanometry (WBT) can distinguish among various kinds of conductive hearing loss and provide additional information.

METHODS

We recruited normal subjects and patients with conductive hearing loss due to the following reasons: tympanic membrane perforation only, ossicular chain problem only, and one or other of those conditions combined with mastoid problems. Wideband absorbance at ambient pressure, peak pressure, resonance frequency, and averaged tympanogram data were measured by WBT and compared between the normal, tympanic membrane perforation only, ossicular chain problem only, and combined with mastoid problems groups.

RESULTS

The normal subjects showed an average peak pressure of -19.51daPa and an average resonance frequency of 965.94Hz. Tympanic membrane perforation only patients showed a very low peak pressure (-124.93daPa) and resonance frequency (73.12Hz). When patients have ossicular chain problems, they showed slightly low peak pressures (43.08daPa) without changes in the resonance frequency (1024.8Hz). Mastoid problem subjects showed slightly decreased resonance frequencies (787.71Hz). Tympanic membrane perforation subjects showed decreased absorbance at low frequencies and ossicular chain problem subjects showed decreases at high frequencies. When comparing the perforation only and ossicular chain subjects by absorbance at 707Hz, the area under the ROC curve was 0.719 (P<0.022). Mastoid problems subjects showed decreased absorbance at all frequencies.

CONCLUSION

WBT can help to distinguish tympanic membrane perforation only and ossicular chain problem patients. WBT may provide additional information on "combined with mastoid problems" patients.

The Effect of Ethnicity on Wideband Absorbance of Neonates with Healthy Middle Ear Functions in Malaysia: A Preliminary Study

BACKGROUND AND OBJECTIVES

Although ethnicity effect on wideband absorbance (WBA) findings was evident for adults, its effect on neonates has not been established yet. This study aimed to investigate the influence of ethnicity on WBA measured at 0 daPa from neonates with healthy middle ear functions.

SUBJECTS AND METHODS

Participants were 99 normal, healthy, full-term newborn babies with chronological age between 11 and 128 hours of age (mean=46.73, standard deviation=26.36). A cross-sectional study design was used to measure WBA at 16 one-third octave frequency points from 99 neonates comprising of three ethnic groups: Malays (n=58), Chinese (n=13) and Indians (n=28). A total of 165 ears (83.3%) that passed a battery of tests involving distortion product otoacoustic emissions, 1 kHz tympanometry and acoustic stapedial reflex were further tested using WBA. Moreover, body size measurements were recorded from each participant.

RESULTS

The Malays and Indians neonates showed almost identical WBA response across the frequency range while the Chinese babies showed lower absorbance values between 1.25 kHz and 5 kHz. However, the differences observed in WBA between the three ethnic groups were not statistically significant (p=0.23). Additionally, there were no statistically significant difference in birth weight, height and head circumference among the three ethnic groups.

CONCLUSIONS

This study showed that Malays, Chinese and Indians neonates were not significantly different in their WBA responses. In conclusion, to apply for the ethnic-specific norms is not warranted when testing neonates from population constitute of these three ethnicities.

Normative Study of Wideband Acoustic Immittance Measures in Newborn Infants

OBJECTIVE

The purpose of this study was to describe normative aspects of wideband acoustic immittance (WAI) measures obtained from healthy White neonates.

METHOD

In this cross-sectional study, wideband absorbance (WBA), admittance magnitude, and admittance phase were measured under ambient pressure condition in 326 ears from 203 neonates (M age = 45.9 hr) who passed a battery of tests, including automated auditory brainstem response, high-frequency tympanometry, and distortion product otoacoustic emissions.

RESULTS

Normative WBA data were in agreement with most previous studies. Normative data for both WBA and admittance magnitude revealed double-peaked patterns with the 1st peak at 1.25-2 kHz and the 2nd peak at 5-8 kHz, while normative admittance phase data showed 2 peaks at 0.8 and 4 kHz. There were no significant differences between ears or gender for the 3 WAI measures. Standard deviations for all 3 measures were highest at frequencies above 4 kHz.

CONCLUSIONS

The 3 WAI measures between 1 kHz and 4 kHz may provide the most stable response of the outer and middle ear. WAI measures at frequencies above 4 kHz were more variable. The normative data established in the present study may serve as a reference for evaluating outer and middle ear function in neonates.

Wideband acoustic immittance in children with Down syndrome: prediction of middle-ear dysfunction, conductive hearing loss and patent PE tubes

OBJECTIVE

The purpose of this study was to evaluate pressurised wideband acoustic immittance (WAI) tests in children with Down syndrome (DS) and in typically developing children (TD) for prediction of conductive hearing loss (CHL) and patency of pressure equalising tubes (PETs).

DESIGN

Audiologic diagnosis was determined by audiometry in combination with distortion-product otoacoustic emissions, 0.226 kHz tympanometry and otoscopy. WAI results were compared for ears within diagnostic categories (Normal, CHL and PET) and between groups (TD and DS).

STUDY SAMPLE

Children with DS (n = 40; mean age 6.4 years), and TD children (n = 48; mean age 5.1 years) were included.

RESULTS

Wideband absorbance was significantly lower at 1-4 kHz in ears with CHL compared to NH for both TD and DS groups. In ears with patent PETs, wideband absorbance and group delay (GD) were larger than in ears without PETs between 0.25 and 1.5 kHz. Wideband absorbance tests were performed similarly for prediction of CHL and patent PETs in TD and DS groups.

CONCLUSIONS

Wideband absorbance and GD revealed specific patterns in both TD children and those with DS that can assist in detection of the presence of significant CHL, assess the patency of PETs, and provide frequency-specific information in the audiometric range.

Factors affecting sound energy absorbance in acute otitis media model of chinchilla

Acute otitis media (AOM) is a rapid-onset infection of the middle ear which results in middle ear pressure (MEP), middle ear effusion (MEE), and structural changes in middle ear tissues. Previous studies from our laboratory have identified that MEP, MEE, and middle ear structural changes are three factors affecting tympanic membrane (TM) mobility and hearing levels (Guan et al., 2014, 2013). Sound energy reflectance or absorbance (EA) is a diagnostic tool increasingly used in clinical settings for the identification of middle ear diseases. However, it is unclear whether EA can differentiate these three factors in an AOM ear. Here we report wideband EA measurements in the AOM model of chinchilla at three experimental stages: unopened, pressure released, and effusion removed. These correspond to the combined and individual effects of the three factors on sound energy transmission. AOM was produced by transbullar injection of Haemophilus influenzae in two treatment groups: 4 days (4D) and 8 days (8D) post inoculation. These time points represent the relatively early and later phase of AOM. In each group of chinchillas, EA at 250-8000 Hz was measured using a wideband tympanometer at three experimental stages. Results show that the effects of MEP, MEE, and tissue structural changes over the frequency range varied with the disease time course. MEP was the primary contributor to reduction of EA in 4D AOM ears and had a smaller effect in 8D ears. MEE reduced the EA at 6-8 kHz in 4D ears and 2-8 kHz in 8D ears and was responsible for the EA peak in both 4D and 8D ears. The residual EA loss due to structural changes was observed over the frequency range in 8D ears and only at high frequencies in 4D ears. The EA measurements were also compared with the published TM mobility loss in chinchilla AOM ears.

Maturation of middle ear transmission in children

The goal of the current study was to characterize the normative features of wideband acoustic immittance in children for describing the functional maturation of the middle ear in 5 to 12-year-old children. Absorbance and group delay were measured in adults and three groups of children, 5-6, 7-9 and 10-12-year-olds, in a cross-sectional design. Absorbance showed significant effects of the age group in four out of ten center frequencies of one-half-octave bins from 211 to 6000 Hz, while there was no significant effect for group delay at any frequency. Older children (10-12 years) showed absorbance similar to adults. Test-retest reliability was high for absorbance for all age groups. However, group delay was modestly reliable only for adults. We conclude that the middle ear transmission follows a protracted period of maturation for high frequencies and reaches adult-like feature by 10-12 years of age.

[Detection of the Presence of Middle-ear Effusion with Wideband Absorbance Tympanometry]

This study evaluated the ability of wideband absorbance (AB) to predict the presence of middle-ear effusion (MEE) in ears with a flat (type B) 226 Hz tympanogram (TG). AB measures were obtained in a no MEE group of 8 ears with a flat TG and a MEE group of 19 ears also with a flat TG. AB was significantly small at frequencies 2 and 4 kHz in the MEE group than in the no MEE group. Based on our results, it appeared that AB could detect MEE with higher specificity than conventional tympanometry. The presence or absence of MEE could be distinguished based on the average AB using 1, 2, and 4 kHz, with 40% as the cutoff point.

Wideband acoustic immittance measurements in assessing crimping status following stapedotomy: A temporal bone study

OBJECTIVE

To ascertain if wideband acoustic immitance (WAI) measurements are useful in assessing crimping status following stapedotomy.

DESIGN

WAI measurements were obtained using the Mimosa Acoustics HearID system. Wideband chirp sound stimuli and a set of tone stimuli for nine frequencies between 0.2 and 6 kHz were used at 60 dB SPL. Five sets of measurements were performed on each temporal bone: mobile stapes, stapes fixation and stapedotomy followed by insertion of a tightly crimped, a loosely crimped and an uncrimped prosthesis.

STUDY SAMPLE

Eight fresh-frozen temporal bones were harvested from human cadaveric donors.

RESULTS

At lower frequencies, up to 1 kHz, stapes fixation decreased absorbance. Compared to the baseline absorbance, absorbance with stapes fixation dropped by 6 to 17% in absolute terms from the baseline value (p = 0.027). Absorbance was not affected in higher frequencies (p = 0.725). Stapedotomy changed the absorbance curve significantly compared to the normal condition with an increase of absolute absorbance values by 6 to 36% around 0.25-1 kHz (p-value <0.01). The crimping conditions did not differ from one another (p = 0.555).

CONCLUSION

WAI is not useful in distinguishing between tightly crimped, loosely crimped and uncrimped stapes prostheses following stapedotomy.

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

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.

Wideband reflectance in Down syndrome

OBJECTIVE

Children with Down syndrome (DS) have a high incidence of middle ear disorders and congenital abnormalities of the external, middle and inner ear. Energy reflectance (ER), a wideband acoustic immittance (WAI) measurement parameter, can measure the sound energy reflected or absorbed in the ear canal over a wider range of frequencies more efficiently and faster than conventional single-tone 226 Hz tympanometry. The aim of the present study was to compare the WAI measurements of children with DS with those of typically developing, normal-hearing children according to their tympanometric findings.

METHODS

Four groups of children with Down syndrome (age range: 2 years and 4 months to 16 years and 3 months; mean age: 8.5 yr) with normal tympanograms (19 ears), flat tympanograms (13 ears), mild negative pressure tympanograms (6 ears between -100 and -199 daPa at the admittance peak) and severe negative pressure tympanograms (4 ears at -200 daPa or lower at the admittance peak) were assessed. All findings were compared with data obtained from 21 ears of a healthy control group (age range: 3 years and 1 month to 13 years and 11 months; mean age: 7.9 yr). The subjects underwent tympanometry with a 226-Hz probe tone frequency and ER measurements along the 200-6,000 Hz range with a chirp stimulus using the Middle-Ear Power Analyzer (MEPA3 - HearID) by Mimosa Acoustics (Champaign, IL), software, version 3.3 [38].

RESULTS

Statistically significant differences were observed in the ER curves for some comparisons between the studied groups. There was also a negative correlation between the static acoustic admittance at the tympanic membrane level and ER measured with a chirp stimulus at 500 and 1,000 Hz. The discriminant analysis technique, which used a chirp stimulus at 1,000 and 1,600 Hz to classify the participants' data based on ER values, achieved a correct classification rate of 59.52% for participants with DS.

CONCLUSION

While groups with abnormal middle ear status, as indicated by tympanometry, showed higher ER values compared to the DS tymp A group and the control group, similar reflectance curves were observed between control group and the DS tymp A group. WAI shows promise as a clinical diagnostic tool in investigating the impact of middle ear disorders in DS group. However, further research is required to investigate this issue in narrower age range group and a larger sample size.

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

A finite element (FE) model was developed based on histological sections of a temporal bone of a 4-year-old child to simulate middle-ear and cochlear function in ears with normal hearing and otitis media. This pediatric model of the normal ear, consisting of an ear canal, middle ear, and spiral cochlea, was first validated with published energy absorbance (EA) measurements in young children with normal ears. The model was used to simulate EA in an ear with middle-ear effusion, whose results were compared to clinical EA measurements. The spiral cochlea component of the model was constructed under the assumption that the mechanics were passive. The FE model predicted middle-ear transfer functions between the ear canal and cochlea. Effects of ear structure and mechanical properties of soft tissues were compared in model predictions for the pediatric and adult ears. EA responses are predicted to differ between adult and pediatric ears due to differences in the stiffness and damping of soft tissues within the ear, and any residual geometrical differences between the adult ear and pediatric ear at age 4 years. The results have significance for predicting effects of otitis media in children.