Otolaryngology outcomes of infants with conductive hearing loss identified through universal newborn hearing screening.

OBJECTIVE: Infants and children diagnosed with a conductive hearing loss (CHL) are often referred for otolaryngology assessment. Although this is also a regular occurrence for infants diagnosed with a CHL through Universal Newborn Hearing Screening (UNHS), less is known about these infants and their outcomes. Using a cohort of infants diagnosed with CHL through UNHS and referred to otolaryngology, this study aimed to investigate the relationship between specific demographic or clinical characteristics and 1) triage category 2) middle ear diagnosis and intervention and, 3) service-related factors at otolaryngology. METHODS: Retrospective analysis through clinical chart review was performed on all infants born between January 2014 and December 2017 who referred on UNHS, diagnosed with a CHL and referred to the Queensland Children's Hospital. Descriptive analysis and Chi squared analysis was conducted on data from 95 records. RESULTS: Analysis between all infants referred from UNHS and those who referred, diagnosed with CHL and then referred to otolaryngology suggest that bilateral referrals/medical exclusion, preterm and infants with ≥1 risk factors are more readily associated with referral to otolaryngology for CHL. Nearly all (92.86 %) infants who were referred to otolaryngology had a primary diagnosis of OM and most infants (89.66 %) received grommets as an intervention. The average age of first appointment at otolaryngology was 427 days, the average age of intervention was 579 days and the average occasions of service at otolaryngology was 6.72. CONCLUSION: This paper provides a snapshot into the journey and outcomes of infants referred from UNHS, diagnosed with CHL, and referred to otolaryngology. Further investigation in both general and UNHS populations is needed to better understand and apply these findings.

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.

Conductive hearing loss in newborns: Hearing profile, risk factors, and occasions of service.

OBJECTIVE: Infants diagnosed with a conductive hearing loss (CHL) are at increased risk of developmental delays. Using a sample of infants diagnosed with CHL through UNHS, this study aimed to investigate the relationship between specific demographic or clinical characteristics and 1) occasions of service to reach a hearing diagnosis and 2) the profile of CHL. METHODS: Retrospective analysis was conducted for all infants with CHL born between 01/01/2007 and 31/12/2018 who had received UNHS. Chi squared analysis was conducted on data from 1208 records. RESULTS: Infants with ≥1 risk factor for hearing loss were more likely to attend more than three occasions of service. Infants who were bilateral refer/medical exclusion, Torres Strait Islander, had ≥1 risk factors for hearing loss or were born pre-term had greater proportions of bilateral CHL than unilateral CHL. Mild to moderate was the most frequent degree of CHL, although a unilateral or bilateral CHL did not have an association with the severity of CHL. Compared to other risk factors, infants with a syndrome had greater proportions of bilateral than unilateral CHL. Risk factors of craniofacial abnormality, prolonged ventilation, or syndrome had greater proportions of mild to moderate CHL than moderate or greater. On average, infants were diagnosed with a CHL at 37.29 weeks of age. CONCLUSION: These findings highlight the relationship between clinical/demographic characteristics and occasions of service to diagnose CHL in children, including the CHL profile. An understanding of this relationship may help clinicians to better plan, assess and manage infants diagnosed with a CHL through UNHS.

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.

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.

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 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.

Clinical characteristics of infants identified with a conductive hearing loss through universal newborn hearing screening: A population-based sample.

BACKGROUND: Universal Newborn Hearing Screening (UNHS) aims to identify infants born with a permanent hearing loss. However, many are also diagnosed with a conductive hearing loss (CHL) and are at subsequent risk for developmental delays. The aim of this study was to investigate the prevalence of CHL and determine which clinical characteristics collected at birth, predict CHL within UNHS. MATERIALS AND METHODS: Retrospective analysis was conducted on all infants born between January 01, 2007 and December 31, 2018. During this period, 731,234 infants were screened, 9802 were direct referrals, and 1208 identified with a CHL. Chi squared analysis and logistic regression was conducted to determine CHL prevalence and identify which clinical characteristics predict CHL. RESULTS: The prevalence of CHL was 12.32%. Following adjustments for collinearity, clinical characteristics that could predict CHL were: bilateral referrals/medical exclusions to screen (Odds ratio, OR 1.89; 95% CI: 1.65-2.1), ≥1 risk factor for hearing loss (OR 2.03; 95% CI: 1.76-2.34), pre-term birth (OR 1.82; 95% CI: 1.57-2.10), male (OR 1.21; 95% CI: 1.07-1.37), and Indigenous status: 'Aboriginal (not Torres Strait Islander)' (OR 1.27; 95% CI:1.03-1.57 and 'not stated' (OR 2.95; 95% CI: 2.02-4.30). CONCLUSION: CHL within UNHS was highly prevalent, with six clinical characteristics that can predict that likelihood of an infant being diagnosed with a CHL. This data could be used to create alternative care pathways for infants with CHL, enabling early and targeted assessments, thereby reducing the risk of developmental delays for these infants.

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.

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

OBJECTIVES: Wideband tympanometry (WBT) measures middle-ear function across a range of frequencies (250 to 8000 Hz) while the ear-canal pressure is varied from +200 to -300 daPa. WBT is a suitable test to evaluate middle-ear function in children, but there is a lack of age-, ear-, gender-, or ethnicity-specific data throughout the literature. The purpose of this study was to investigate the effects of age, ear laterality, gender, and ethnicity on the WBT data retrieved from children aged 4 to 13 years determined to have normal middle-ear function. DESIGN: Data were collected cross-sectionally from 924 children aged 4 to 13 years who passed a test battery consisting of 226-Hz tympanometry, ipsilateral acoustic stapedial reflexes, and pure-tone screening, and without significant history of middle-ear dysfunction. Participants were grouped according to their age: 4 to 6 years, 7 to 9 years, 10 to 13 years. Wideband absorbance values were extracted at 0 daPa (WBA0) and tympanometric peak pressure (WBATPP). RESULTS: The effects of age, frequency, and pressure (WBA0 versus WBATPP) were statistically significant. There were significant differences between WBA0 and WBATPP for all age groups such that WBA0 had lower absorbance at low frequencies (250 to 1600 Hz) and greater absorbance at mid to high frequencies (2500 to 8000 Hz). Statistically significant effects of age were present for WBA0 and WBATPP such that absorbance generally increased with age from 250 to 1250 Hz and decreased with age from 2000 to 5000 Hz. There were no significant main effects of gender, ear, or ethnicity. CONCLUSIONS: Gender-, ear-, and ethnicity-specific clinical WBA0 and WBATPP norms are not required for diagnostic purposes; however, age-specific norms may be necessary. Age-related changes in middle-ear function were observed across WBA0 and WBATPP. The data presented in this study are a suitable clinical reference for evaluating the outer- and middle-ear function of school-aged children.

Learning difficulties and auditory processing deficits in a clinical sample of primary school-aged children.

Objective: The current study examined the relationship between learning and auditory processing (AP) ability in a clinical sample of children with and without learning difficulties (LD).Design: A non-randomised, cross-sectional, single measure research design was used.Study sample: The participants consisted of 50 children (7.7-10.8 years) who had been referred for a clinical AP assessment based on having been referred from a school-based AP screening. These children had previously been identified as having (n = 14) or not having (n = 36) LD.Results: Children with LD performed significantly worse than children without LD on frequency patterns with linguistic reports (FPlinR and FPlinL), dichotic digits (DD) and Auditory Word Memory - Forward (ANMF) tests, with significant correlations being observed between these variables and the learning score. The multiple linear regression showed that FPlinR, DDR and ANMF scores explained 50% of the variance in the learning score.Conclusion: The present study's results are most consistent with risk factor models linking AP to learning abilities in children where reduced AP abilities could put children at greater risk for LD. Further investigations into the potential relationships between AP, cognition, speech and language development, and learning ability in children are warranted.

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.

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

OBJECTIVES: Wideband absorbance (WBA) is an emerging technology to evaluate the conductive pathway (outer and middle ear) in young infants. While a wealth of research has been devoted to measuring WBA at ambient pressure, few studies have investigated the use of pressurized WBA with this population. The purpose of this study was to investigate the effect of age on WBA measured under pressurized conditions in healthy infants from 0 to 6 months of age. DESIGN: Forty-four full-term healthy neonates (17 males and 27 females) participated in a longitudinal study. The neonates were assessed at 1-month intervals from 0 to 6 months of age using high-frequency tympanometry, acoustic stapedial reflex, distortion product otoacoustic emissions, and pressurized WBA. The values of WBA at tympanometric peak pressure (TPP) and 0 daPa across the frequencies from 0.25 to 8 kHz were analyzed as a function of age. RESULTS: A linear mixed model analysis, applied to the data, revealed significantly different WBA patterns among the age groups. In general, WBA measured at TPP and 0 daPa decreased at low frequencies (<0.4 kHz) and increased at high frequencies (2 to 5and 8 kHz) with age. Specifically, WBA measured at TPP and 0 daPa in 3- to 6-month-olds was significantly different from that of 0- to 2-month-olds at low (0.25 to 0.31 kHz) and high (2 to 5 and 8 kHz) frequencies. However, there were no significant differences between WBA measured at TPP and 0 daPa for infants from 3 to 6 months of age. CONCLUSIONS: The present study provided clear evidence of maturation of the outer and middle ear system in healthy infants from birth to 6 months. Therefore, age-specific normative data of pressurized WBA are warranted.

Hearing and Auditory Processing Abilities in Primary School Children with Learning Difficulties.

OBJECTIVES: This study aimed to investigate hearing and auditory processing ability in primary school children with learning difficulties (LD). DESIGN: A nonrandomized, cross-sectional single measure research design was used. A total of 486 children, aged 7.7 to 10.8 years and attending years 3 and 4 in six primary schools, were classified as having an LD (n = 67) or being typically developing (TD, n = 419). This classification was based on a Learning Score generated from their school report results and National Assessment Program - Literacy and Numeracy scores. All children attempted a conventional hearing assessment (CHA) involving pure-tone audiometry, tympanometry, acoustic reflexes (AR), and otoacoustic emissions (OAEs). Children returning pure-tone audiometry results within normal limits also attempted an auditory processing assessment (APA) including dichotic digits (DD) and low-pass filtered speech (LPFS) tests. RESULTS: In children with LD, 21/67 (31.4%) failed the CHA, 20/58 (34.5%) failed the APA, and 32/58 (55.2%) failed the overall hearing assessment (OHA) if they failed either or both CHA and APA. In comparison, in TD children, 55/413 (13.3%) failed the CHA, 52/314 (16.6%) failed the APA, and 86/313 (27.5%) failed the OHA. Proportionally, children with LD were 2.4 times more likely than TD children to fail the CHA, 2.1 times more likely to fail the APA, and 2.0 times more likely to fail the OHA. In children who had completed the OHA, multiple linear regressions showed average AR thresholds, DD scores, and LPFS scores explained 13 to 18% of the variance in the Learning Score. CONCLUSION: The potential for hearing impairment should be investigated in children with LD. These investigations should begin with CHA, and for children returning normal-hearing thresholds, should continue with measures of AR, DD, and LPFS, to ensure these children receive the appropriate auditory support needed to enhance their learning.