[Wideband acoustic immittance characteristics and machine learning-based diagnostic model for children with large vestibular aqueduct syndrome]

Objective:This study was to investigate the wideband acoustic immittance（WAI） characteristics of children with large vestibular aqueduct syndrome（LVAS） and to construct a diagnostic model for LVAS based on WAI and machine learning（ML） techniques. Methods:We performed a retrospective analysis of the data from 38 children（76 ears） with LVAS and 44 children（88 ears） with normal hearing. The data included conventional audiological examination, temporal bone CT scan and WAI test. We performed statistical analysis and developed multivariate diagnostic models based on different ML techniques. Results:The two groups were balanced in terms of ear, gender, and age（P>0.05）. The wideband absorbance（WBA） of the LVAS group was significantly lower than that of the control group at 1 000-2 519 Hz, while the WBA of the LVAS group was significantly higher than that of the control group at 4 000-6 349 Hz（P<0.05）. WBA at 5 039 Hz under ambient pressure had a certain diagnostic value（AUC=0.767）. The multivariate diagnostic model had a high diagnostic value（AUC>0.8）, among which the KNN model performed the best（AUC=0.961）. Conclusion:The WAI characteristics of children with LVAS are significantly different from those of normal children. The diagnostic model based on WAI and ML techniques has high accuracy and reliability, and provides new ideas and methods for intelligent diagnosis of LVAS.

Improvement of vertigo symptoms and acoustic power absorbance in cases with endolymphatic hydrops

Objective

The pathophysiology and symptoms underlying Meniere's disease (MD) manifest as endolymphatic hydrops (EH), potentially impacting acoustic power absorbance in vestibular EH. The longitudinal effects of middle ear pressure therapy (MEPT) and conservative therapies for EH by magnetic resonance imaging (MRI) and on acoustic power absorbance on wideband acoustic immittance (WAI) were evaluated, and their changes were compared with clinical symptoms.

Methods

Eleven patients with definite MD or delayed endolymphatic hydrops (DEH), resistant to conservative therapies and who continued MEPT for 1 year, were included. Vertigo scores, hearing levels, acoustic power absorbance on WAI, and degrees of EH on 3-T MRI were evaluated and compared before and after the treatments.

Results

One year after the start of MEPT, all cases showed symptomatic improvement in vertigo score; however, the degrees of EH showed no improvements except in one case. In the affected ears with EH, their absorbances on WAI improved, particularly at 1580-1905 or 2400-2953 Hz (p < .05).

Conclusion

Alleviation of vestibular symptoms with the therapy of MD was not necessarily associated with improved EH. Vestibular symptoms could be related to the change in the impedance of inner ear pressure, which was proven by the normalization of acoustic power absorbance. Assessments of acoustic power absorbance may provide useful information for physiological conditions and causative factors of vertigo in ears with EH.

Level of evidence

4.

[Analysis of wideband acoustic immittance measurements in patients with unilateral Ménière's disease]

Objective:To investigate the characteristics of wideband acoustic immittance（WAI） measurements in patients with unilateral Ménière's disease（MD） and evaluate the clinical value of WAI in diagnosis of MD. Methods:WAI was performed in 30 patients with unilateral MD（30 ears for symptomatic and 30 ears for asymptomatic） and in 26 healthy individuals（52 ears）（control group）. The WAI measurements, including the frequency first appearing two peaks in energy absorbance（EA） tympanogram, resonance frequency（RF）, the peak value of absorbance（PVA）, the integral area of absorbance（IAA）, EA curve at peak pressure, were analyzed. Results:①The occurrence of two peaks in EA tympanogram in both the MD symptomatic and asymptomatic ear was observed in 27 ears（84.4%）, and 38 ears（70.4%） in the control group, with no significant difference in the frequency of first appearing in two peaks onset between the groups（all P>0.05）. ②The RF of the MD symptomatic ears was significantly lower than that of the asymptomatic ears（t=-3.544, P=0.001） and that of the control subjects（t=2.084, P=0.041）; there was no difference of RF between the MD asymptomatic ears and the control group（P>0.05）. ③The PVA were significantly lower in both MD symptomatic（t=4.240, P<0.01） and asymptomatic ears（t=4.202, P=0.001） than in controls. ④The IAA in MD symptomatic（t=3.295, P=0.001） and asymptomatic ears（t=3.193, P=0.003） was significantly lower than in the control group. ⑤Comparison of the EA curve at peak pressure of the three groups: the EAs of MD symptomatic ears were lower than those of the control group at the range of 1 059-2 911 Hz（all P<0.05）; the EAs of MD symptomatic ears were lower than those of MD asymptomatic ears within 1 000 Hz and 1 834-2 119 Hz（all P<0.05）; the EAs of MD asymptomatic ears were lower than those of the control group at the range of 515-2 748 Hz（all P<0.05）. Conclusion:Symptomatic ears in unilateral MD patients show alterations in some WAI measurements compared to asymptomatic ears and/or controls, suggesting that middle ear mechanical fuction of the affected side may be modified due to the endolymphatic hydrops. The clinical significance of WAI needs to be further explored in the context of evaluating MD.

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.

[A preliminary study on wideband acoustic immittance of infants with normal bilateral middle ear function at the age of 1-5 months]

Objective:To explore preliminary characteristics of wideband acoustic immittance of 1- to 5-month-old infants who have bilateral normal middle ear function, so as to contribute to the clinical application of WAI test in the evaluation of middle ear function in infants. Methods:1- to 5-month-old infants were included. After the normal function of bilateral middle ear was determined by otoacoustic emission and high frequency acoustic immittance test, WAI test was performed and the relevant data were collected and analyzed. Results:There was no statistical difference in absorbance at the same frequency between the left ear and right ear of each group（P>0.05）. Absorbance of 4000 Hz increased at first and then decreased with the growth of physiological age, and the sound energy absorption rate of other frequencies decreased except 2670 Hz and 3364 Hz. Conclusion:The outcome of this study shows that it is necessary to establish the national normal value of WAI in 1- to 5-month-old infants who have bilateral normal middle ear function. The purpose of the development of middle ear system is to ensure that sounds in the speech frequency range can be transmitted and heard more effectively.

Wideband Acoustic Reflex Measurement

Acoustic reflex thresholds (ART) obtained using pure-tone probe stimuli as part of a traditional immittance test battery can be used to evaluate site of lesion and provide a cross-check with behavioral results. ARTs obtained as part of a wideband acoustic immittance (WAI) test battery using a click as the probe stimulus can be used in the same way with the added benefit that they may provide lower ARTs than those obtained using a pure-tone probe. Another benefit of the WAI ART test is that it can be completed without requiring a hermetic seal or pressurizing the ear canal. A new adaptive method of obtaining ARTs using WAI techniques may cut test time in half, thus making this an attractive option for future clinical use. More advanced uses of WAI ART tests include the measurement of AR growth functions. These may be used to investigate the possible effects of synaptopathy related to high levels of noise exposure and possible auditory deficits related to ototoxicity.

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.

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

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

The Rise and Fall of Aural Acoustic Immittance Assessment Tools

Clinical assessment of middle ear function has undergone multiple transformations and developments since the first acoustic impedance measurements were made in human ears nearly a century ago. The decades following the development of the first acoustic impedance bridge by Metz in 1946 witnessed a series of technological advancements leading to the widespread use of single-frequency admittance tympanometry in the 1960s. In the 1970s, multi-frequency and multi-component tympanometry (MFT) emerged for clinical use, allowing for a better understanding of the middle ear acoustic-mechanical response at frequencies between 200 and 2,000 Hz. MFT has not gained widespread clinical adoption despite its advantages over single-frequency tympanometry. More recent technological developments enabled assessment for frequencies greater than 2,000 Hz, leading to the advent of wideband acoustic immittance measures with capabilities for comprehensive assessment of middle ear acoustic mechanics, and a great potential for use of acoustic immittance testing in various diagnostic practices. This article reviews important historical markers in the development and operation of middle ear assessment tools and analysis methods. Technical and clinical factors underlying the emergence and adoption of different acoustic immittance tests as a standard of clinical practice are described. In addition, we discuss the likelihood for widespread adoption of wideband acoustic immittance and wideband tympanometry in future clinical practice.

Fundamental Concepts for Assessment and Interpretation of Wideband Acoustic Immittance Measurements

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

Effects of earlens lens placement on sound field thresholds, tympanometric measurements and wideband acoustic immittance

OBJECTIVE

The Earlens is a direct-drive hearing device consisting of a lens which physically displaces the umbo to achieve appropriate gain. The objective is to determine the clinical acceptability of clinical immittance measurements in Earlens wearers.

DESIGN

Controlled before-after within-subjects repeated measures study.

STUDY SAMPLE

Data is reported for measurements obtained on 15 subjects (average age of 72.2 years) with data from 30 ears.

RESULTS

There was a small effect of lens placement on sound field thresholds in most subjects. The largest damping effect of 4 dB was observed at 1000 Hz. An average reduction of 0.17 mL was identified in compliance following lens placement (p < 0.05). An effect of the lens on power absorbance obtained at ambient and peak pressure was found. The lens resulted in an increase in power absorbance at low frequencies (below 500 Hz) and a decrease in the mid to high-frequency range of approximately 500-3500 Hz (p < 0.05).

CONCLUSIONS

Lens wear had a small effect on audiometric thresholds and tympanometry for most patients. Clinicians who use compliance and power absorbance should take into consideration lens effects on these measurements. Additional work is required to develop clinical normative ranges of these measures for wearers of the Earlens.

[Characteristics and differential diagnosis of middle ear cholesteatoma and chronic suppurative otitis media with wideband acoustic immittance]

Objective:Through analysis of the sound energy absorbance of wideband acoustic immittance to provide a basis for differential diagnosis of adult acquired secondary cholesteatoma of the middle ear and patients with chronic suppurative otitis media（CSOM）. Methods:38 cases of cholesteatoma and 40 cases of CSOM admitted to the Department of Otolaryngology, Affiliated Hospital of Xuzhou Medical University from September 2020 to December 2021 were selected as the research group, and 30 cases （60 ears） of normal adults were selected as the control group. A total of 16 frequency points were selected, and the energy absorbance of wideband acoustic immittance was taken as the research parameter. The characteristics of energy absorbance under ambient pressure among the three are compared. Then the ROC in the cholesteatoma group was drawn, and by calculating the AUC, the Cut-off values and the corresponding sensitivity and specificity were found. Results:The energy absorbance in CSOM group at 1100-5700 Hz and the cholesteatoma group at 560-5700 Hz was lower than that in the control group, and the difference in some frequency bands was statistically significant. The energy absorbance in the cholesteatoma group at 226-7100 Hz was lower than that in the CSOM group, and the difference between the two groups in many frequency points was statistically significant. The ROC in the research group was drawn and it was found that the AUC in the 560, 710, 890, and 4500 bands was > 0.5, and in the other bands was > 0.7（P<0.05）. The AUC in the 2800 Hz was the largest （0.78）, the Cut-off value was 0.31, the corresponding sensitivity was 78.38%, specificity was 73.33%. Conclusion:Wideband acoustic immittance can be used as an auxiliary method for the differential diagnosis of adult-acquired secondary cholesteatoma of the middle ear and chronic suppurative otitis media in adults.

[Eigenvalue analysis of wideband acoustic immittance in secretory otitis media in children of different ages]

Objective:The characteristic values of broadband acoustic immittance of children of different ages during secretory otitis media were collected resonance frequency and absorption rate of middle ear in children of different ages were compared. Methods:Eighty-two children with secretory otitis media were selected for the broadband acoustic immittance test, including 62 cases （83 ears） in the young effusion group（[3.5±0.7]months）, and 20 cases （40 ears） in the older effusion group（[4.0±0.6]years old）. 82 normal children were selected for broadband acoustic immittance test in the same environment, including 62 cases （124 ears） in the younger normal group and 20 cases （40 ears） in the older normal group. The resonance frequency and absorptivity of different age groups under broadband peak pressure were compared, and the frequency absorptivity curve was drawn for analysis. Results:The resonance frequencies of older normal group and younger normal group, older effusion group and older normal group, younger effusion group and younger normal group, older effusion group and younger effusion group were statistically significant（P<0.001）. Analysis of sound energy absorption rate at different ages. There was significant difference in sound energy absorption rate between older normal group and younger normal group at 226-1155 / 4757-8000 Hz（P<0.001）. The difference of full frequency sound energy absorption rate between the older effusion group and the older normal group was statistically significant（P<0.001）, among which the difference of 866-1542 / 2520-4362 Hz absorption rate was the largest. The difference of full frequency sound energy absorption rate between young effusion group and young normal group was statistically significant（P<0.001）, and the difference of 1091-2245 / 3776-5494 Hz absorption rate was the largest. Conclusion:Middle ear effusion in children of different ages has different performance under broadband acoustic immittance peak pressure, and has its own characteristic acoustic energy absorption frequency band. This study provides a reference basis for the analysis of the characteristics of middle ear sound transmission in children with secretory otitis media in the future.

[A preliminary study on characteristics of wideband acoustic immittance in patients with Meniere's disease]

Objective:To explore the wideband absorbance characteristics of patients with Meniere's disease（MD）. Methods:Wideband acoustic immittance was performed in 52 patients with unilateral Meniere's disease（UMD） and 30 control subjects with normal hearing. All UMD patients underwent pure tone audiometry, 226 Hz acoustic immittance, wideband acoustic immittance, and gadolinium contrast MRI. Sixteen frequency points were chosen to analyze the wideband absorbance at ambient and peak pressure, and the subjects were grouped as UMD group vs. control group and asymptomatic group. The student's t-test was used to compare the absorbance difference between them. Results:Both at peak and ambient pressure, there was a significant difference between the MD group and control group at 1587 Hz, 2000 Hz, 2519 Hz, 3174 Hz, and 4000 Hz; the MD group was lower than the control group（P<0.05）; there were no differences between the asymptomatic group and the symptomatic group, there also was a significant difference between the asymptomatic group and control group at 1587-4000 Hz（P<0.05）. Conclusion:The wideband absorbance in MD patients was significantly reduced within the frequency range of 1587-4000 Hz, and wideband acoustic immittance seems to be cost-effective in predicting MD.

Mechanics of Total Drum Replacement Tympanoplasty Studied With Wideband Acoustic Immittance

OBJECTIVE

Poor hearing outcomes often persist following total drum replacement tympanoplasty. To understand the mechanics of the reconstructed eardrum, we measured wideband acoustic immittance and compared the mechanical characteristics of fascia-grafted ears with the normal tympanic membrane.

STUDY DESIGN

Prospective comparison study.

SETTING

Tertiary care center.

METHODS

Patients who underwent uncomplicated total drum replacement with temporalis fascia grafts were identified. Ears with healed grafts, an aerated middle ear, and no other conductive abnormalities were included. All patients underwent pre- and postoperative audiometry. Wideband acoustic immittance was measured with absorbance and impedance computed. Fascia-grafted ears were compared with normal unoperated ears.

RESULTS

Eleven fascia-grafted ears without complications were included. Postoperatively, the median air-bone gap was 15 dB (250-4000 Hz), with variation across frequency and between ears. Fifty-six control ears were included. Absorbance of fascia-grafted ears was significantly lower than that of normal ears at 1 to 4 kHz (P < .05) but similar below 1 kHz. Impedance magnitude demonstrated deeper and sharper resonant notches in fascia-grafted ears than normal ears (P < .05), suggesting lower mechanical resistance of the fascia graft.

CONCLUSION

The mechanics of fascia-grafted ears differ from the normal tympanic membrane by having lower absorbance at mid- to high frequencies and thus poor sound transmission. The lower resistance in fascia-grafted ears may be due to poor coupling of the graft to the malleus. To improve sound transmission, grafts for tympanic membrane reconstructions would benefit from refined mechanical properties.

Effect of Middle-Ear Pathology on High-Frequency Ear Canal Reflectance Measurements in the Frequency and Time Domains

The effects of middle-ear pathology on wideband acoustic immittance and reflectance at frequencies above 6-8 kHz have not been documented, nor has the effect of such pathologies on the time-domain reflectance. We describe an approach that utilizes sound frequencies as high as 20 kHz and quantifies reflectance in both the frequency and time domains. Experiments were performed with fresh normal human temporal bones before and after simulating various middle-ear pathologies, including malleus fixation, stapes fixation, and disarticulation. In addition to experimental data, computational modeling was used to obtain fitted parameter values of middle-ear elements that vary systematically due to the simulated pathologies and thus may have diagnostic implications. Our results demonstrate that the time-domain reflectance, which requires acoustic measurements at high frequencies, varies with middle-ear condition. Furthermore, the extended bandwidth frequency-domain reflectance data was used to estimate parameters in a simple model of the ear canal and middle ear that separates three major conductive pathologies from each other and from the normal state.

[The study of wideband acoustic immittance normative data of young people]

Objective:To explore the normative data of wideband acoustic absorption rate of young people with normal hearing, and the related factors of wideband acoustic immittance.Method:Eighty six cases of young people with normal hearing (43 cases of male, 43 cases of female) were collected in the clinical audiology centers of Beijing Tongren Hospital, Capital University of Medical. The average age is (22.0±1.5) years. Pure tone audiometry in the range of 250 to 8 000 Hz in each octave is carried out, and the air conduction thresholds are less than 25 dB HL; 226 Hz tympanometry were type A. For all subjects, the wideband acoustic immittance measurement was conducted at 226-8 000 Hz, and a total of 107 frequency points were carried out.Result:The test results of 172 ears were statistically analyzed.①In the range of 250-8 000 Hz,acoustic absorption rate in the low frequency range increases gradually, and the peak is found in the range of 1 000 to 3 000 Hz;getting along with the increase of frequency and acoustic absorption rate gradually decreases slowly.②The acoustic absorption rate in the range of 4 200-4 900 Hzin female subjects was significantly higher than that in male subjects.③There was no significant relationship between gender, compliance, peak pressure, and width in 226 Hz tympanometry (P=0.319, 0.831, 0.786), however there was a significant relationship between gender and the ear canal volume (P<0.01).④There was no significant relationship between gender and the resonance frequency (P>0.05).⑤There was a significant correlation between height/weight and ear canal volume (P<0.05), and there was a significant relationship between the ear canal volume and the resonance frequency (P<0.05).Conclusion:The acoustic absorption rate of young people in the low frequency range was lower, then increases gradually, and the peak was found in the range of mid-high frequency. The difference in the wideband absorption rate between genders was significant. The height and weight had influence on the results of wideband acoustic immittance.