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

Stochastic modeling of the human middle ear dynamics under pathological conditions

BACKGROUND

Although the dynamics of the middle ear (ME) have been modeled since the mid-twentieth century, only recently stochastic approaches started to be applied. In this study, a stochastic model of the ME was utilized to predict the ME dynamics under both healthy and pathological conditions.

METHODS

The deterministic ME model is based on a lumped-parameter representation, while the stochastic model was developed using a probabilistic non-parametric approach that randomizes the deterministic model. Subsequently, the ME model was modified to represent the ME under pathological conditions. Furthermore, the simulated data was used to develop a classifier model of the ME condition based on a machine learning algorithm.

RESULTS

The ME model under healthy conditions exhibited good agreement with statistical experimental results. The ranges of probabilities from models under pathological conditions were qualitatively compared to individual experimental data, revealing similarities. Moreover, the classifier model presented promising results.

DISCUSSION

The results aimed to elucidate how the ME dynamics, under different conditions, can overlap across various frequency ranges. Despite the promising results, improvements in the stochastic and classifier models are necessary. Nevertheless, this study serves as a starting point that can yield valuable tools for researchers and clinicians.

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

Objectives

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

Design

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

Study sample

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

Results

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

Conclusions

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

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.

Measuring resonance frequency of the middle ear in school-aged children: potential applications for detecting middle ear dysfunction

OBJECTIVE

This study established a normative range of resonance frequency (RF) values as estimated using Wideband Tympanometry (WBT) and determined the ability of WBT-estimated RF to predict the presence of middle ear dysfunction in school-aged children.

DESIGN

Cross-sectional data were collected using a hearing screening test battery consisting of WBT, Pure Tone Screening (PTS), 226- kHz tympanometry, and ipsilateral Acoustic Stapedial Reflexes (ASR).

STUDY SAMPLE

About 1590 children aged 4-13 years.

RESULTS

RF significantly decreased from 4 to 13 years of age (4-6 years, 928.95  kHz; 7-9 years, 872.80  kHz; 10-13 years, 863.68  kHz). RF had area under the receiver operating characteristic curve (AROC) values between 0.589 and 0.626 to predict ears that failed PTS or 226- kHz tympanometry. RF below 627  kHz accurately predicted the presence of a Type B tympanogram (AROC 0.945). RF had high test-retest reliability with Intra-Class Coefficient value of 0.817 and good agreement according to Bland-Altman plot analysis.

CONCLUSIONS

WBT-estimated RF had fair diagnostic accuracy for predicting PTS and tympanometry results, but had excellent accuracy for predicting the presence of middle ear dysfunction, indicated by a Type B tympanogram. WBT-estimated RF does not require age-, gender-, ear- or ethnicity-specific normative data for clinical use with children.

Comparison of wideband acoustic immittance in Chinese infants under three months of age with normal and abnormal middle ear function

OBJECTIVES

This study aims to compare the characteristics of Wideband Acoustic Immittance (WAI) in Chinese infants under three months of age, with either normal or abnormal middle ear function.

METHODS

We recruited 98 infants with either normal or abnormal middle ear function, and subsequently divided them into four groups based on their middle ear function and chronological age. The absorbances at tympanometric peak pressure (TPP) were collected across 1/3rd octave frequencies ranging from 226 to 8000 Hz.

RESULTS

Among infants with normal middle ear function, no significant differences were observed concerning ear laterality. However, significant differences were noted at 3364 Hz and 4000 Hz with respect to age. For infants with either normal or abnormal middle ear function, we found significant differences at the majority of frequencies. Additionally, the receiver operating characteristic (ROC) curves and maxima Youden index indicated that absorbances at 1682 Hz and 1297 Hz could be employed to evaluate the middle ear function of infants at 1 and 2 months of age.

CONCLUSION

This study demonstrates that WAI holds promise as a valuable tool for assessing the middle ear condition of infants at 1 and 2 months of age. Infants aged 1 and 2 years, having absorbance values equal to or greater than 0.7470 at 1682 Hz and 0.6775 at 1297 Hz respectively, may indicate normal middle ear function. Furthermore, it underscores the necessity of establishing ethnicity- and age-specific norms for WAI in infants under 3 months of age.

Absorbance Measurements From Normal-hearing Ears in the National Health and Nutrition Examination Survey, 2015-2016 and 2017-2020

OBJECTIVE

To summarize absorbance and impedance angles from normal-hearing ears within the 2015-2016 and 2017-2020 US National Health and Nutrition Examination Surveys (NHANES).

DESIGN

Two publicly available NHANES datasets were analyzed. Ears meeting criteria for normal hearing and valid absorbance and impedance angle measurements were identified. Measurements were summarized via descriptive statistics within categories of age cohort, race/ethnicity cohort, sex (male, female), and ear (left, right).

RESULTS

A total of 7029 ears from 4150 subjects, ages 6 to 80 years, met inclusion criteria. Differences between subgroups within all categories (age, race/ethnicity, sex, and ear) were fractions of the sample SDs. The largest differences occurred between age cohorts younger than 20 years.

CONCLUSIONS

The NHANES absorbance and impedance angle measurements are consistent with published literature. These results demonstrate that trained professionals, using the Titan instrument in a community setting inclusive of all demographics, produce comparable measurements to those in laboratory settings.

Characteristics of large vestibular aqueduct syndrome in wideband acoustic immittance

Objective

To describe the characteristics of large vestibular aqueduct syndrome (LVAS) in wideband acoustic immittance (WAI) and to explore whether inner ear deformity has an impact on WAI results.

Methods

Subjects with typical LVAS (LVAS group) and control subjects with a normal anatomical structure of the inner ear (control group) were screened from pediatric patients with cochlear implants using thin-slice computed tomography (CT) images of the temporal bone. With inflammation of the auditory canal and middle ear excluded by routine ear examination and 226 Hz acoustic immittance, WAI data were acquired. Then, the maximum absorbance as the major observation indicator on the mean tympanogram was compared between the LVAS group and control group, and a descriptive comparison of the mean tympanogram and frequency-absorbance curve at peak pressure was performed between the two groups.

Results

The LVAS group included 21 cases (38 ears), and the control group included 27 cases (45 ears). All LVAS subjects met the Valvassori criteria, and the VA at the horizontal semicircular canal displayed flared expansion. On the mean tympanogram, the maximum absorbance in the LVAS group (0.542 ± 0.087) was significantly higher than that in the control group (0.455 ± 0.087) (p < 0.001). The tympanogram in the LVAS group showed an overall elevation, and the absorbance at all pressure sampling points was significantly higher than that in the control group (p < 0.001). The frequency-absorbance curve at peak pressure first increased and then decreased in both groups, and the LVAS group showed higher absorbance than the control group in the frequency range below 2,828 Hz. The absorbance at 343-1,124 Hz was significantly different between the two groups (p < 0.001), and 343-1,124 Hz was the major frequency range at which the maximum absorbance on the mean tympanogram increased in the LVAS group.

Conclusion

Large vestibular aqueduct syndrome (LVAS) shows increased absorbance in low and medium frequency ranges in WAI. The maximum absorbance on the mean tympanogram can serve as a reliable evaluation indicator. Inner ear factors must be considered when middle ear lesions are analyzed by WAI.