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.

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.

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 Tympanometry Findings in Healthy Neonates.

OBJECTIVES: The objective of the present study was to describe pressurized wideband absorbance at tympanometric peak pressure (WBATPP) and 0 daPa (WBA0) in healthy Caucasian neonates. SUBJECTS: A total of 249 ears from 249 neonates who passed a test battery of 1,000-Hz tympanometry, distortion product otoacoustic emissions and automated auditory brainstem response were included in the study. METHOD: WBATPP and WBA0 were averaged in one-third octave frequencies from 0.25 to 8 kHz. Data were statistically analyzed for effects of frequency, ear, and gender. RESULTS: Normative WBATPP and WBA0 data obtained from healthy neonates are presented. There was no significant difference between WBATPP and WBA0 at all frequencies. Both WBATPP and WBA0 demonstrated a multipeaked pattern with maxima of 0.80 and 0.72 at 1.25 to 1.5 and 6 kHz, respectively, and two minima of 0.45 and 0.49 at 0.4 to 0.5 and 4 kHz, respectively. The effects of ear and gender were not significant for both WBA measures. CONCLUSION: Pressurized WBATPP and WBA0 data were provided for healthy Caucasian neonates. They will be useful for the assessment of middle ear function and assist in differentiating between conductive and sensorineural hearing losses in neonates.

High frequency (1000 Hz) tympanometry in six-month-old infants.

OBJECTIVES: High frequency tympanometry (HFT) using a 1000 Hz probe tone is recommended for infants from birth to six months of age. However, there is limited normative HFT data outside the newborn period. The objective of this study was to describe HFT data in healthy six-month-old infants. METHODS: HFT and distortion product otoacoustic emission (DPOAE) tests were performed on 168 six-month-old full-term healthy infants. Ears that passed DPOAEs and had a single-peaked tympanogram were included for analysis. The tympanometric measures included in the normative HFT data were tympanometric peak pressure (TPP), peak compensated static admittance (Ytm) and tympanometric width (TW). RESULTS: A total of 118 ears from 118 infants who passed DPOAE and had single-peaked tympanograms were included in the analysis. Normative data were presented for TPP, Ytm and TW. A comparison of the present study with studies on neonates and younger infants revealed significantly higher mean Ytm and lower mean TPP for six-month-old-infants. CONCLUSION: Significant differences in HFT findings between neonates and six-month-old infants suggest a developmental trend and confirm the need for separate age-appropriate norms for the tympanometric measures. Normative HFT data described in the present study may provide useful information for optimizing the diagnosis of conductive conditions in six-month-old infants.

Predictive Accuracy of Wideband Absorbance at Ambient and Tympanometric Peak Pressure Conditions in Identifying Children with Surgically Confirmed Otitis Media with Effusion.

BACKGROUND: Wideband absorbance (WBA) measured at ambient pressure (WBAA) does not directly account for middle ear pressure effects. On the other hand, WBA measured at tympanometric peak pressure (TPP) (WBATPP) may compensate for the middle ear pressure effects. To date, there are no studies that have compared WBAA and WBATPP in ears with surgically confirmed otitis media with effusion (OME). PURPOSE: The purpose of this study was to compare the predictive accuracy of WBAA and WBATPP in ears with OME. RESEARCH DESIGN: Prospective cross-sectional study. STUDY SAMPLE: A total of 60 ears from 38 healthy children (mean age = 6.5 years, SD = 1.84 years) and 60 ears from 38 children (mean age = 5.5 years, SD = 3.3 years) with confirmed OME during myringotomy were included in this study. DATA COLLECTION AND ANALYSIS: Results were analyzed using descriptive statistics and analysis of variance. The predictive accuracy of WBAA and WBATPP was determined using receiver operating characteristics (ROC) analyses. RESULTS: Both WBAA and WBATPP were reduced in ears with OME compared with that in healthy ears. The area under the ROC (AROC) curve was 0.92 for WBAA at 1.5 kHz, whereas that for WBATPP at 1.25 kHz was 0.91. In comparison, the AROC for 226-Hz tympanometry based on the static acoustic admittance (Ytm) measure was 0.93. CONCLUSIONS: Both WBAA and WBATPP showed high and similar test performance, but neither test performed significantly better than 226-Hz tympanometry for detection of surgically confirmed OME.

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 (WBAamb) of both experimental groups was reduced significantly between 0.8 and 5 kHz relative to the control group. The difference between mean WBAamb and mean WBA at tympanometric peak pressure (WBATPP) 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 WBAamb of both epitympanic RP (ERP) and epitympanic cholesteatoma (EC) subgroups was significantly lower than that of the control group. Mean WBATPP of the ERP subgroup attained normal levels as per the control group, while mean WBATPP 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 WBAamb and WBATPP values. No significant differences in WBAamb and WBATPP 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 WBAamb and WBATPP 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.

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.

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 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.

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; WBATPP) 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, WBATPP, 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 WBATPP in Aboriginal children. Aboriginal boys had significantly higher WBATPP than girls at 1.5 and 2 kHz. A significant effect of ethnicity was also noted for WBATPP at 3, 4, and 8 kHz, with Caucasian children demonstrating higher WBATPP 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, WBATPP, 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.

Eustachian Tube Dysfunction and Wideband Absorbance Measurements at Tympanometric Peak Pressure and 0 daPa.

BACKGROUND: Although wideband absorbance (WBA) provides important information about middle ear function, there is limited research on the use of WBA to evaluate eustachian tube dysfunction (ETD). To date, WBA obtained under pressurized condition has not been used to evaluate ETD. PURPOSE: The objective of the study was to compare WBA at 0 daPa and tympanometric peak pressure (TPP) conditions in healthy ears and ears with ETD. Research Design: A cross-sectional study design was used. Study Sample: A total of 102 healthy ears from 79 participants (mean age = 10.0 yr) and 43 ears from 32 patients with ETD (mean age = 16.0 yr) were included in this cross-sectional study. WBA was measured at 0 daPa (WBA0) and TPP WBA at TPP (WBATPP). DATA COLLECTION AND ANALYSIS: WBA results were analyzed using descriptive statistics and t-tests with the Bonferroni correction. An analysis of variance with repeated measures was applied to the data. RESULTS: WBA0 was significantly lower in the ETD group than in the control group. The WBA0 of the control group demonstrated a broad peak between 1.25 and 4 kHz, whereas the WBA0 of the ETD group had a peak between 2.5 and 4 kHz. WBATPP of the ETD group approached values close to that of the control group. In the control group, WBATPP was only 0.06 to 0.09 higher than WBA0, whereas in the ETD group, WBATPP was 0.29 to 0.42 higher than WBA0 between 0.6 and 1.5 kHz. A differential pattern of WBA at TPP relative to 0 daPa was observed between ears with ETD and ears with otitis media with effusion (OME) and negative middle ear pressure (NMEP). CONCLUSIONS: Hence, a comparison of WBA0 and WBATPP can provide potentially useful diagnostic information, and hence can be used as an adjunct tool to evaluate ETD. This is important especially in young children or some adults who are unable to perform maneuvers such as Toynbee or Valsalva during ETD assessment. Further research is needed to verify the results using test performance measures to determine whether WBA0 and WBATPP can objectively determine the presence of ETD or OME with NMEP.

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.

Development of a Diagnostic Prediction Model for Conductive Conditions in Neonates Using Wideband Acoustic Immittance.

OBJECTIVES: Wideband acoustic immittance (WAI) is an emerging test of middle-ear function with potential applications for neonates in screening and diagnostic settings. Previous large-scale diagnostic accuracy studies have assessed the performance of WAI against evoked otoacoustic emissions, but further research is needed using a more stringent reference standard. Research into suitable quantitative techniques to analyze the large volume of data produced by WAI is still in its infancy. Prediction models are an attractive method for analysis of multivariate data because they provide individualized probabilities that a subject has the condition. A clinically useful prediction model must accurately discriminate between normal and abnormal cases and be well calibrated (i.e., give accurate predictions). The present study aimed to develop a diagnostic prediction model for detecting conductive conditions in neonates using WAI. A stringent reference standard was created by combining results of high-frequency tympanometry and distortion product otoacoustic emissions. DESIGN: High-frequency tympanometry and distortion product otoacoustic emissions were performed on both ears of 629 healthy neonates to assess outer- and middle-ear function. Wideband absorbance and complex admittance (magnitude and phase) were measured at frequencies ranging from 226 to 8000 Hz in each neonate at ambient pressure using a click stimulus. Results from one ear of each neonate were used to develop the prediction model. WAI results were used as logistic regression predictors to model the probability that an ear had outer/middle-ear dysfunction. WAI variables were modeled both linearly and nonlinearly, to test whether allowing nonlinearity improved model fit and thus calibration. The best-fitting model was validated using the opposite ears and with bootstrap resampling. RESULTS: The best-fitting model used absorbance at 1000 and 2000 Hz, admittance magnitude at 1000 and 2000 Hz, and admittance phase at 1000 and 4000 Hz modeled as nonlinear variables. The model accurately discriminated between normal and abnormal ears, with an area under the receiver-operating characteristic curve (AUC) of 0.88. It effectively generalized to the opposite ears (AUC = 0.90) and with bootstrap resampling (AUC = 0.85). The model was well calibrated, with predicted probabilities aligning closely to observed results. CONCLUSIONS: The developed prediction model accurately discriminated between normal and dysfunctional ears and was well calibrated. The model has potential applications in screening or diagnostic contexts. In a screening context, probabilities could be used to set a referral threshold that is intuitive, easy to apply, and sensitive to the costs associated with true- and false-positive referrals. In a clinical setting, using predicted probabilities in conjunction with graphical displays of WAI could be used for individualized diagnoses. Future research investigating the use of the model in diagnostic or screening settings is warranted.

Predictive Accuracy of Sweep Frequency Impedance Technology in Identifying Conductive Conditions in Newborns.

BACKGROUND: Diagnosing conductive conditions in newborns is challenging for both audiologists and otolaryngologists. Although high-frequency tympanometry (HFT), acoustic stapedial reflex tests, and wideband absorbance measures are useful diagnostic tools, there is performance measure variability in their detection of middle ear conditions. Additional diagnostic sensitivity and specificity measures gained through new technology such as sweep frequency impedance (SFI) measures may assist in the diagnosis of middle ear dysfunction in newborns. PURPOSE: The purpose of this study was to determine the test performance of SFI to predict the status of the outer and middle ear in newborns against commonly used reference standards. RESEARCH DESIGN: Automated auditory brainstem response (AABR), HFT (1000 Hz), transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), and SFI tests were administered to the study sample. STUDY SAMPLE: A total of 188 neonates (98 males and 90 females) with a mean gestational age of 39.4 weeks were included in the sample. Mean age at the time of testing was 44.4 hr. DATA COLLECTION AND ANALYSIS: Diagnostic accuracy of SFI was assessed in terms of its ability to identify conductive conditions in neonates when compared with nine different reference standards (including four single tests [AABR, HFT, TEOAE, and DPOAE] and five test batteries [HFT + DPOAE, HFT + TEOAE, DPOAE + TEOAE, DPOAE + AABR, and TEOAE + AABR]), using receiver operating characteristic (ROC) analysis and traditional test performance measures such as sensitivity and specificity. RESULTS: The test performance of SFI against the test battery reference standard of HFT + DPOAE and single reference standard of HFT was high with an area under the ROC curve (AROC) of 0.87 and 0.82, respectively. Although the HFT + DPOAE test battery reference standard performed better than the HFT reference standard in predicting middle ear conductive conditions in neonates, the difference in AROC was not significant. Further analysis revealed that the highest sensitivity and specificity for SFI (86% and 88%, respectively) was obtained when compared with the reference standard of HFT + DPOAE. Among the four single reference standards, SFI had the highest sensitivity and specificity (76% and 88%, respectively) when compared against the HFT reference standard. CONCLUSIONS: The high test performance of SFI against the HFT and HFT + DPOAE reference standards indicates that the SFI measure has appropriate diagnostic accuracy in detection of conductive conditions in newborns. Hence, the SFI test could be used as adjunct tool to identify conductive conditions in universal newborn hearing screening programs, and can also be used in diagnostic follow-up assessments.

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.

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.

Sweep frequency impedance measures in young infants: developmental characteristics from birth to 6 months.

OBJECTIVE: International Journal of Audiology To study the developmental characteristics of sweep frequency impedance (SFI) measures in healthy infants from birth to 6 months. DESIGN: All infants were assessed using high-frequency tympanometry (HFT), distortion product otoacoustic emission (DPOAE) and SFI tests. SFI measures consisted of measurement of resonance frequency (RF) and mobility (ΔSPL) of the outer and middle ear. A mixed model analysis of variance was applied to the SFI data to examine the effect of age on RF and ΔSPL. STUDY SAMPLE: Study included 117 ears from 83 infants of different age groups from birth to 6 months. RESULTS: The mean RF of the outer ear increased from 279 Hz at birth to 545 Hz at 4 months, whereas mean ΔSPL of the outer ear decreased from 7.9 dB at birth to 3.7 dB at 4 months of age. In contrast, the mean RF and ΔSPL of the middle ear did not change significantly with age up to 6 months. CONCLUSIONS: Developmental characteristics should be considered when evaluating the function of the outer and middle ear of young infants (≤6 months) using the SFI. The preliminary normative SFI data established in this study may be used to assist with the evaluation.

Effects of ear canal static pressure on the dynamic behaviour of outer and middle ear in newborns.

OBJECTIVE: The present study investigated the effect of ear canal pressure on the dynamic behaviour of the outer and middle ear in newborns with and without a conductive condition using the sweep frequency impedance (SFI) technology. METHODS: A test battery consisting of automated auditory brainstem response (AABR), transient evoked otoacoustic emission (TEOAE) and 1000-Hz tympanometry (HFT) was performed on 122 ears of 86 healthy newborns and 10 ears of 10 newborns with a conductive condition (failed TEOAE and HFT). The dynamic behaviour of the outer and middle ear, when the pressure applied to the ear canal was varied from 200 to -200daPa, was evaluated in terms of the sound pressure level (SPL) in the ear canal, resonance frequency (RF) and displacement (ΔSPL). RESULTS: Application of either a positive or negative static pressure to the ear canal of healthy newborns increased the resonance frequency of the outer (RF1) and middle ear (RF2), but decreased the displacements of the outer (ΔSPL1) and middle ear (ΔSPL2). Positive static pressures resulted in lower SPL while negative static pressures resulted in higher SPL than that at ambient pressure (0daPa). At -200daPa, more than 90% of ears showed signs of collapsed ear canal. The dynamic behaviour under various positive and negative static pressures for newborn ears with a conductive condition indicated similar pattern of SPL, RF1 and ΔSPL1 responses for the outer ear as per healthy ears, but abnormal responses for the middle ear. CONCLUSIONS: While both positive and negative pressures applied to the ear canal have the same effect of stiffening the outer and middle ear, negative pressure of up to -200daPa resulted in more than 90% of ears with a collapsed ear canal. The results of the present study do not only offer useful clinical information for differentiating healthy ears from ears with a conductive condition, but also provide information on the maturation aspects of the outer and middle ear in newborns.