Wideband Tympanometry: Normative Data for Young Iranian Adults.

INTRODUCTION: The middle ear sound transmission features can impact acoustic sounds reaching the inner ear. Wideband tympanometry (WBT) or wideband acoustic immittance is an effective and desirable measurement of conductive conditions in newborns and adults and has appropriate sensitivity to distinguish different pathologies like otosclerosis from other middle ear conflicts. Recently, there has been an increased utilization of WBT, which highlights the importance of collecting population-based normative data as a necessary step in the standardization of this test, as well as for its clinical application. This study aimed to obtain normative data on WBT in the adult Iranian ethnic. METHODS: There were 101 participants (202 ears) consisting of 53 males (57.4%) and 48 females (42.6%) in the age range of 19-29 years. The Titan WBT device (Interacoustics, Assens, Denmark) was used for WBT measurements. The broadband click was utilized as the probe tone between frequencies of 250 Hz and 8,000 Hz. All the participants underwent ear, nose, and throat assessments, pure-tone audiometry, and conventional tympanometry (226 Hz). Features like equivalent ear canal volume (Veq), tympanometric peak pressure, gradient, resonance frequency (RF), energy absorbance (EA), and admittance (Ad) were tested. RESULTS: In this cross-sectional study, 202 ears were tested for WBT. EA increased by frequency enhancement; at 1 kHz and 2 kHz the EA was the most prominent; at 2,519 Hz, it started decreasing, and at 8 kHz, there was a slight increase. There was also a significant difference in the Veq and Ad between males and females. Studies have shown that the Veq may vary between male and female subjects based on body size. CONCLUSION: In this study, normative data for the WBT were obtained from young Iranian adults with normal hearing ranges and middle ear conditions. We hope that this study and the resulting norm will provide a basis for increasing the use of WBT in Iranian diagnostic and clinical practices.

Sound energy absorbance changes in the elderly with presbycusis with normal outer and middle ear.

OBJECTIVE: This study aimed to investigate the wideband tympanometry (WBT) findings in the elderly with presbycusis who have normal outer and middle ears according to otoscopic examination and traditional tympanometry, and to determine whether there is a relationship between the middle ear wideband absorbance value and the pure tone air-bone gap (ABG) observed especially at mid-high frequencies in the elderly. METHODS: The study included 30 elderly with presbycusis (> 65 years old, presbycusis group) and 30 healthy individuals (control group) between the ages of 18 and 55. Pure tone air conduction and bone conduction thresholds of all participants were determined and WBT was applied to all participants. Resonance frequency (RF), absorbance ratios at peak pressure (PPAR) and ambient pressure (APAR) values were analyzed. RESULTS: The RF value of the presbycusis group was lower than the control group (p < 0.05). APAR and PPAR values at 2000 and 4000 Hz and mean absorbance values of the presbycusis group were lower than the control group (p < 0.05). APAR was higher at 500 Hz in males than females (p < 0.05), but there was no difference between genders in RFs (p > 0.05). A moderate negative correlation was observed between ABG and both PPAR and APAR at 4000 Hz in presbycusis group (p < 0.05). CONCLUSION: it was determined that there was a decrease in RF and absorbances at 2000 and 4000 Hz in the elderly with presbycusis. Aging affects not only the inner ear but also the conduction mechanism of the middle ear. Our findings may be effective in a more accurate and reliable interpretation of WBT in the elderly with presbycusis.

Evaluation of middle ear and hearing status of ankylosing spondylitis patients with wideband tympanometry and pure tone audiometry tests.

OBJECTIVES: The aim of this study was to evaluate the middle and inner ear function and hearing status of Ankylosing spondylitis (AS) patients. METHODS: One hundred twenty-four ears of 62 patients with AS and 90 ears (control group) of 45 healthy subjects were included in the study. The hearing levels of the participants were assessed with pure tone and high-frequency audiometry at the octave frequency between 250 and 16,000 Hz. The absorbance rates and resonance frequencies of middle ear were measured with the wideband tympanometry (WBT) test. AS group was divided into subgroups based on the disease activity, duration of follow-up, medications used for AS, and the subgroups were compared according to hearing status and absorbance and resonance frequencies of middle ears. RESULTS: A statistically significant difference was found between the AS and control groups in terms of air and bone conduction thresholds at frequencies of 250, 500, 1000, 2000, and 4000 Hz and the mean PTA1, PTA2, and PTA3 values (p < 0.05). In contrast, no statistically significant difference was observed between two groups in terms of high-frequency thresholds (8000-16,000 Hz). Although the middle ear resonance frequency obtained from the WBT test was higher in the AS group compared to the control group, no significant difference was observed (p > 0.05). The severity of disease adversely affected the hearing threshold at 250, and 500 Hz for air conduction, at 500 Hz for bone conduction threshold, and at PTA1 (p < 0.05). The duration and severity of disease did not affect absorbance values of WBT (p > 0.05). CONCLUSION: To our knowledge, this is the first study to demonstrate the effects of AS patients on the middle ear function with WBT and to report middle ear absorbance values and resonance frequency changes in AS patients. The higher resonance frequency values found by WBT in AS patients may be due to the stiffness that develops as a result of middle ear involvement. According to pure tone and high-frequency audiometry findings, it has been seen that AS leads to SNHL especially at low frequencies.

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.

Wideband tympanometry as a diagnostic tool for Meniere's disease: a retrospective case-control study.

PURPOSE: The main purpose of this study was to investigate the usefulness of wide band tympanometry (WBT) as a diagnostic tool for Ménière's disease (MD) by comparing differences in absorbance measures between normal hearing ears and patient diagnosed with MD. METHODS: We conducted a retrospective case-control study. From a cohort of 116 patients diagnosed with Ménière disease, 52 MD patients and 99 normal hearing adults with no history of otological disease served as subjects. Wideband tympanometry was conducted using at Titan Impedance module and audiometry was performed with a MADSEN Astera2. Mean energy absorbance curves with 95% confidence intervals were computed across cases with MD and controls in the frequency range 226-8000 Hz. An overall test for difference between curves of cases and controls was calculated by multivariate analysis of variance. RESULTS: The MD group and the subpopulations of MD patients who fulfilled the International criteria for MD showed a statistically significant lower absorbance at tympanic peak pressure compared to the control group (p < 0.001). No overlap of confidence intervals between mean curves was found within the frequency range of 2000-4000 Hz. CONCLUSION: Absorbance measures obtained by WBT were able to distinguish between MD ears and normal ears within the frequency range of 2000-4000 Hz. The results indicate that WBT potentially could be a useful and simple non-invasive diagnostic tool for MD. However, more research on the association between absorbance measures and inner ear pathologies is needed.

Wideband tympanometry in ears with superior canal dehiscence before and after surgical correction.

OBJECTIVES: Wideband tympanometry (WBT) has been shown to be sensitive to mechanical changes in the ear. This study investigated the effect of surgical correction of superior canal dehiscence (SCD) on WBT (i.e. absorbance and middle ear resonance frequency) compared to those on common surgical outcomes such as symptom resolution, vestibular evoked myogenic potentials (VEMP), and hearing thresholds. STUDY SAMPLE AND STUDY DESIGN: Seven patients (eight ears with SCD) who underwent surgical correction of SCD underwent WBT in addition to pure-tone audiometry and VEMP assessment. RESULTS: Postoperatively, all ears showed normalised/decreased absorbance at low frequencies and slightly enhanced absorbance in the middle frequency range (7/8 ears). The middle ear resonance frequency, which was initially lower than normal in most patients, increased in 6/8 operated ears, and decreased in two ears with no/partial symptom relief. In comparison, complete symptom control was observed in 6/8 operated ears, VEMP amplitudes reduced or normalised in all ears, and hearing thresholds remained stable or improved in 6/8 ears and worsened in two ears. CONCLUSIONS: Surgery seems to change the response to WBT in patients with SCD. The results of WBT may represent mechanical changes induced by SCD, and should be considered when evaluating surgical outcomes.

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.

Clinical benefit of wideband-tympanometry: a pediatric audiology clinical study.

PURPOSE: Wideband-tympanometry (WBT) could give more informative data about the tympanic condition than the conventional tympanometry. In the actual literature, the clinical profit of wideband-tympanometry in pediatric audiological settings is not well evaluated. The aim of this study was to analyze the additional clinical benefit. METHODS: 150 children (281 ears) with normal hearing, at the age from 11 days up to 14;10 years, checked with pure tone audiometry or auditory brainstem responses (ABR) participated in this retrospective study. We divided in four age ranges (≤ 6 month; > 6 month ≤ 3 years; > 3 years ≤ 11 years; > 11 years). All children were evaluated with ENT examination including ear microscopy, conventional 226-Hz or 1000-Hz tympanometry and WBT. Ear canal volumes were determined. RESULTS: Compared with literature data, our patients aged ≤ 3 years showed smaller mean ear canal volumes (≤ 4 ml). We found a good statistical correlation between the WBT-results and 1000-Hz tympanometry but a rare correlation between WBT-results and ear microscopic findings. In the patients with pathologic ear microscopic results in all groups of age, a significant reduction of WBT-absorbance in 1000 Hz and 2000 Hz was found. CONCLUSIONS: This study confirms that WBT collects additive data to detect the correct middle ear status. In pediatric audiology, WBT is an additional useful method to value middle ear problems and to analyze the character of infantile hearing loss. Standard guidelines for the interpretation of the pediatric population are needed. Hence, it will be necessary to determine these findings in a larger number of infantile ears.

Effect of ear canal pressure and age on wideband absorbance in young infants.

OBJECTIVE: The study investigated the effect of ear canal pressure and age on wideband absorbance (WBA) in healthy young infants. DESIGN: Using a cross-sectional design, WBA at 0.25 to 8 kHz was obtained from infants as the ear canal pressure was swept from +200 to -300 daPa. STUDY SAMPLE: The participants included 29 newborns, 9 infants each at 1 and 4 months and 11 infants at 6 months of age who passed distortion product otoacoustic emissions test. RESULTS: In general, negative-ear canal pressures reduced WBA across the frequency range, while positive-ear canal pressures resulted in reduced WBA from 0.25 to 2 kHz and above 4 kHz with an increase in absorbance between 2 and 3 kHz compared to WBA at ambient pressure. The variation in WBA below 0.5 kHz, as the pressure was varied, was the greatest in newborns. But, the variation was progressively reduced in older infants up to the age of 6 months, suggesting stiffening of the ear canal with age. CONCLUSIONS: Significant changes in WBA were observed as a function of pressure and age. In particular, developmental effects on WBA were evident during the first six months of life.

Evaluating Wideband Tympanometry Absorbance Changes in Cochlear Implant Recipients: Mechanical Insights and Influencing Parameters.

Background: Cochlear implant (CI) electrode insertion can change the mechanical state of the ear whereby wideband tympanometry absorbance (WBTA) may serve as a sensitive tool to monitor these mechanical changes of the peripheral auditory pathway after CI surgery. In WBTA, the amount of acoustic energy reflected by the tympanic membrane is assessed over a wide frequency range from 226 Hz to 8000 Hz. The objective of this study was to monitor changes in WBTA in CI recipients before and after surgery. Methods: Following otoscopy, WBTA measurements were conducted twice in both ears of 38 standard CI recipients before and in the range of 4 to 15 weeks after CI implantation. Changes from pre- to postoperative absorbance patterns were compared for the implanted as well as the contralateral control ear for six different frequencies (500 Hz, 750 Hz, 1000 Hz, 2000 Hz, 3000 Hz, 4000 Hz). Furthermore, the influence of the time point of the measurement, surgical access, electrode type, sex and side of the implantation were assessed for the implanted and the control ear in a linear mixed model. Results: A significant decrease in WBTA could be observed in the implanted ear when compared with the contralateral control ear for 750 Hz (p < 0.01) and 1000 Hz (p < 0.05). The typical two-peak pattern of WBTA measurements was seen in both ears preoperatively but changed to a one-peak pattern in the newly implanted ear. The linear mixed model showed that not only the cochlear implantation in general but also the insertion through the round window compared to the cochleostomy leads to a decreased absorbance at 750 and 1000 Hz. Conclusions: With WBTA, we were able to detect mechanical changes of the acoustical pathway after CI surgery. The implantation of a CI led to decreased absorbance in the lower frequencies and the two-peak pattern was shifted to a one-peak pattern. The result of the linear mixed model indicates that WBTA can detect mechanical changes due to cochlear implantation not only in the middle ear but also in the inner ear.

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.

The effects of cochlear implantation on middle ear function: A prospective study.

OBJECTIVES: Although sound conduction mechanisms may influence by cochlear implantation (CI), it is not very clear whether, how, and to what extent these mechanisms may be influenced the pediatric population. Wideband tympanometry (WBT) is a sensitive tool to evaluate alternations in the middle ear mechanics in a wide frequency range. The current study aimed to explore CI's impacts on sound conduction across the middle ear cavity using WBT in pediatrics. METHODS: In a prospective design, 35 unilaterally implanted children (<24 months of age) with normal temporal bone anatomy were included in this study. Traditional tympanometry (226-Hz) and WBT measures were compared for each child in the implanted and non-implanted ears preoperatively and three months postoperatively. RESULTS: No significant changes in the "static acoustic admittance" and "peak pressure" parameters were observed between the pre-CI and post-CI conditions in the implanted and non-implanted ears in the 226-Hz tympanometry test. Wideband absorbance recordings before CI surgery exhibited a double-peaked pattern over a frequency range of 250 to 8000 Hz. The pre- and postoperative acoustic energy absorbance comparisons indicated a significantly reduced mid-frequency (1260 to 3175 Hz) and high-frequency (5040 to 8000 Hz) absorbance in the implanted ears. However, our results indicated no significant differences in sound absorbance between the pre- and postoperative conditions in non-implanted ears. CONCLUSION: Our findings suggested that WBT is a more sensitive method than traditional tympanometry for monitoring the mechanical status of the middle ear after cochlear implantation in pediatrics. Cochlear implantation in young children can significantly reduce mid- and high-frequency acoustic absorbance measured by WBT.

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.

[Characteristics of wideband tympanometry in patients with Ménière's disease based on neutral network].

Objective:To construct a prediction model for Ménière's disease based on neural network and evaluate its prediction ability. Methods:Sixty-four patients with Ménière's disease underwent gadolinium enhanced magnetic resonance imaging of inner ear which showed endolymphatic hydrops. Meanwhile, 40 healthy adults were enrolled as controls. The database of wideband tympanometry of patients and control subjects was analyzed, and the neural network model was established by MATLAB 2021a software. The prediction ability of the model was evaluated by accuracy, positive predictive value, negative predictive value, the Youden index, sensitivity, specificity, receiver operating characteristic curve and area under curve （AUC）. Results:A feedforward network model was built with a single hidden layer to predict Ménière's disease with wideband tympanometry. There were 104 features in the input layer, 13 neuron nodes in the hidden layer and 1 output neuron in the output layer. The accuracy of the model was 83.2%, the positive predictive value was 80.7%, the negative predictive value was 84.3%, the sensitivity was 76.5%, the specificity was 83.7%, the Youden index was 0.602, and the AUC was 0.855. Conclusion:Based on neural network, the prediction model of Ménière's disease with high accuracy was constructed according to the results of wideband tympanometry, which provided reference for the diagnose of Ménière's disease.

Inter-rater reliability of the diagnosis of otitis media based on otoscopic images and wideband tympanometry measurements.

OBJECTIVES: This study aims to investigate the inter-rater reliability and agreement of the diagnosis of otitis media with effusion, acute otitis media, and no effusion cases based on an otoscopy image and in some cases an additional wideband tympanometry measurement of the patient. METHODS: 1409 cases were examined and diagnosed by an otolaryngologist in the clinic, and otoscopy examination and wideband tympanometry (WBT) measurement were conducted. Afterwards, four otolaryngologists (Ear, Nose, and Throat doctors, ENTs), who did not perform the acute examination of the patients, evaluated the otoscopy images and WBT measurements results for diagnosis (acute otitis media, otitis media with effusion, or no effusion). They also specified their diagnostic certainty for each case, and reported whether they used the image, wideband tympanometry, or both, for diagnosis. RESULTS: All four ENTs agreed on the diagnosis in 57% of the cases, with a pairwise agreement of 74%, and a Light's Kappa of 0.58. There are, however, large differences in agreement and certainty between the three diagnoses. Acute otitis media yields the highest agreement (77% between all four ENTs) and certainty (0.90), while no effusion shows much lower agreement and certainty (34% and 0.58, respectively). There is a positive correlation between certainty and agreement between the ENTs across all cases, and both certainty and agreement increase for cases where a WBT measurement is shown in addition to the otoscopy image. CONCLUSIONS: The inter-rater reliability between four ENTs was high when diagnosing acute otitis media and lower when diagnosing otitis media with effusion. However, WBT can add valuable information to get closer to the ground-truth diagnosis without myringotomy. Furthermore, the diagnostic certainty increases when the WBT is examined together with the otoscopy image.

Wideband acoustic immittance in superior semicircular canal dehiscence.

OBJECTIVE: The apparent effect of superior semicircular canal dehiscence (SSCD) on middle ear- and cochlear impedance has led researchers to investigate the use of wideband acoustic immittance as a screening tool when SSCD is suspected. The purpose of the study was to describe the absorbance characteristics and tympanometric values of ears with confirmed SSCD measured at tympanometric peak pressure (TPP) and at ambient pressure. METHODS: Wideband Acoustic Immittance was performed at ambient pressure and at TPP on ten participants (12 ears) with confirmed SSCD, as well as on an age- and gender matched control group (12 ears). Inferential statistics were used to determine whether statistical differences existed for the absorbance values at each of the averaged frequencies, the resonance frequency (RF) and tympanometric data between the SSCD and control groups. RESULTS: The mean absorbance of the SSCD group reached a maximum at 890.9 Hz and a minimum at 6349.6 Hz. When testing absorbance at TPP, a statistically significant increase/peak in the absorbance values of the SSCD group (compared to those of the control group) was found from 630 to 890.9 Hz and a decrease from 4489.8 to 6349.6 Hz. Similar patterns were observed for absorbance at ambient pressure. A lower mean RF for ears with SSCD as well as an increased mean admittance magnitude (AM) value at RF was found compared to those of the control group. CONCLUSION: The use of SSCD as a screening tool when SSCD is suspected was strengthened by results similar to those of previous studies. As a result of the significant difference in RF of SSCD ears compared to the RF of the control group, the potential value of measuring the RF of the middle ear to differentiate between mass-and stiffness dominated pathologies, was also illustrated.

The Role of Wideband Tympanometry in the Diagnosis of Meniere's Disease.

Meniere's disease (MD) is a clinical syndrome characterized by spontaneous recurrent vertigo, usually accompanied by hearing loss, tinnitus, and aural fullness. The cause of MD remains unclear and is generally considered to be associated with endolymphatic hydrops. Studies showed that patients with MD could have eustachian tube dysfunction (ETD). ETD can disrupt the pressure balance between the middle and inner ear and impair the inner ear's function. In recent years, several studies have attempted to identify MD by using wideband tympanometry (WBT). However, there are limited studies in this area. There is no consensus on how to use WBT to diagnose Meniere's disease. Therefore, we endeavored to conduct a narrative review in this aspect based on the latest research findings. Reduction in resonance frequency and absorbance are characteristic of MD and can identify Meniere's disease. The use of an increase in the integrated area of absorbance as an indicator for identifying MD is controversial. WBT seems to be ineffective as a diagnostic tool during the acute episodes of Meniere's disease. Patients with MD may benefit from WBT. WBT has excellent potential for future use in Meniere's disease. However, further large sample sizes, multicenter studies are needed.

Anticipating real-ear insertion response using an external auditory canal model.

OBJECTIVES: This study aimed to determine the acoustic characteristics of the external auditory canal (EAC) and predict the real-ear aided response (REAR) using an EAC model that includes the standing wave effect. METHODS: The EAC transfer function equations were derived by summing the incoming and outgoing waves. First, we investigated the real-ear unaided gain (REUG). Second, seven patients (eight ears) wearing hearing aids (HAs) were enrolled as subjects to examine the REAR. We conducted wideband tympanometry (WBT) to measure the absorbance, the frequency response at 65 dB (65dB-FR) of the HAs, and the measured REAR for an international speech test signal (ISTS) at 65 dB. RESULTS: The EAC model that includes the standing-wave effect is considered to be valid from examination of the REUG. A significant correlation was found between the measured and calculated REARs at 900 Hz, 1000 Hz, 2000 Hz, and 3000 Hz in an uncorrelated test. A two-way analysis of variance (ANOVA) found significant differences in the 65dB-FR and the measured REARs at 800, 900, 1000, and 2000 Hz, but this difference disappeared after correction of the calculated acoustic characteristics of the EAC. CONCLUSIONS: By measuring the WBT characteristics and correcting them with an EAC model, the in-situ REAR can be determined from the HA characteristics in the mid-frequency range. There is a risk of insufficient HA amplification in the mid-frequency range when no real-ear measurements are performed.

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.