Carlie Driscoll

Outcomes of transient evoked otoacoustic emission testing in 6-year-old school children : a comparison with pure tone screening and tympanometry

OBJECTIVES (1) To establish test performance measures for Transient Evoked Otoacoustic Emission testing of 6-year-old children in a school setting; (2) To investigate whether Transient Evoked Otoacoustic Emission testing provides a more accurate and effective alternative to a pure tone screening plus tympanometry protocol. METHODS Pure tone screening, tympanometry and transient evoked otoacoustic emission data were collected from 940 subjects (1880 ears), with a mean age of 6.2 years. Subjects were tested in non-sound-treated rooms within 22 schools. Receiver operating characteristics curves along with specificity, sensitivity, accuracy and efficiency values were determined for a variety of transient evoked otoacoustic emission/pure tone screening/tympanometry comparisons. RESULTS The Transient Evoked Otoacoustic Emission failure rate for the group was 20.3%. The failure rate for pure tone screening was found to be 8.9%, whilst 18.6% of subjects failed a protocol consisting of combined pure tone screening and tympanometry results. In essence, findings from the comparison of overall Transient Evoked Otoacoustic Emission pass/fail with overall pure tone screening pass/fail suggested that use of a modified Rhode Island Hearing Assessment Project criterion would result in a very high probability that a child with a pass result has normal hearing (true negative). However, the hit rate was only moderate. Selection of a signal-to-noise ratio (SNR) criterion set at > or =1 dB appeared to provide the best test performance measures for the range of SNR values investigated. Test performance measures generally declined when tympanometry results were included, with the exception of lower false alarm rates and higher positive predictive values. The exclusion of low frequency data from the Transient Evoked Otoacoustic Emission SNR versus pure tone screening analysis resulted in improved performance measures. CONCLUSIONS The present study poses several implications for the clinical implementation of Transient Evoked Otoacoustic Emission screening for entry level school children. Transient Evoked Otoacoustic Emission pass/fail criteria will require revision. The findings of the current investigation offer support to the possible replacement of pure tone screening with Transient Evoked Otoacoustic Emission testing for 6-year-old children. However, they do not suggest the replacement of the pure tone screening plus tympanometry battery.

Transient evoked otoacoustic emissions in 6-year-old school children: a normative study

Great potential has recently been demonstrated for the application of transient evoked otoacoustic emissions (TEOAEs) in screening the hearing of school-aged children. The present study aimed to describe the range of TEOAE values obtained from a large cohort of 6-year-old children in school settings. Results indicated significant sex and ear asymmetry effects on signal-to-noise ratio, response, whole wave reproducibility, band reproducibility and noise levels. A prior history of ear infections was also shown to influence response level, whole wave reproducibility and band reproducibility. The sex, ear and history specific normative data tables derived may contribute to future improvements in the accuracy of hearing screening for 6-year-old school children.

Monitoring for postnatal hearing loss using risk factors: a systematic literature review.

Objectives: The aim of this study was to investigate whether there was evidence-based support for targeted surveillance programs using a risk-factor registry to detect postnatal hearing loss or whether other programs were available that may be more effective than targeted surveillance. Particularly, it addressed questions that arose along the targeted surveillance pathway, including: (1) the risk factors used to determine a referral, (2) referral frequencies, (3) the relationship between risk factors and a postnatal hearing loss, and (4) other systems that may be more efficient than the use of risk factors. Design: A systematic literature review was completed in peer-reviewed and non–peer-reviewed databases. Methods: Publications were obtained using the databases MEDLINE, Cumulative Index of Nursing and Allied Health Literature, and Excerpta Medica on line, and by inspecting the reference lists of relevant articles and expert-committee papers. Quality assessment ratings and data extraction were completed by the research team. Results: In total, 40 articles met the inclusion criteria and were included in this review. The outcomes drawn from these studies were inconclusive as they were based on small sample sizes and largely from single sites only. With this in mind, from the information obtained: (1) gestational age, low-birth weight, toxoplasmosis, other infections, rubella, cytomegalovirus (CMV), herpes simplex virus infections, craniofacial anomalies, respirator support, and the administration of aminoglycosides were the more commonly reported risk factors in programs; (2) referral frequency for monitoring appointments was approximately 3%; and (3) CMV, extracorporeal membrane oxygenation, congenital diaphragmatic hernia, and persistent pulmonary hypertension of the newborn were associated with postnatal hearing loss, whereas, preauricular skin tags and ear pits, low-birth weight, and toxoplasmosis were not. The review also identified that second-phase universal screening programs, CMV screening, and genetic screening should be explored as potential additions or alternatives to targeted surveillance using risk factors. Conclusions: Further large-scale, population-based research on available programs for the detection of postnatal hearing loss should be conducted to improve present practice and assist with the development of evidence-based guidelines for hearing monitoring.

Transient Evoked Otoacoustic Emissions in Two-month-old Infants: A Normative Study

Researchers have recently reported the effects of age, sex, ear asymmetry, and subjects activity status on transient evoked otoacoustic emissions (TEOAEs). The present study aimed to expand upon such reports by describing the characteristics of TEOAE spectra obtained from a cohort of 607 two-month-old infants in community child health clinics. Results indicated significant sex, ear and activity state effects on the signal:noise ratio, response, whole wave and band reproducibility values. These findings suggest the need for TEOAE normative data to be expressed as a function of sex, ear, and activity state of infants. These characteristics of TEOAE spectra may shape future investigations into appropriate pass fail criteria for two-month-old infants.

High-frequency pure-tone audiometry in children: a test-retest reliability study relative to ototoxic criteria.

Objective: Good test–retest reliability of high frequency (≥8 kHz) pure-tone audiometry (HFPTA) is essential to detect significant changes in hearing threshold caused by ototoxicity. While the test–retest reliability of HFPTA in adults has been extensively studied, such investigations in children are scant. This study aimed to evaluate the test–retest reliability of the HFPTA in normal-hearing children with particular reference to the criteria for ototoxicity. Design: Participants were 125 children aged between 4 and 13 yr, with normal hearing in the 0.25 to 4 kHz range and normal tympanometric findings. The participants were divided into three age groups, 4 to 6 yr (16M; 16F); 7 to 9 yr (22M; 30F); and 10 to 13 yr (24M; 17F), for investigating possible age effects in the test–retest reliability of HFPTA. The instrumentation for the HFPTA procedure was an Interacoustics AC40 audiometer with Koss R/80 high-frequency headphones, calibrated to meet Australian standards. Hearing thresholds at 8, 9, 10, 11.2, 12.5, 14, and 16 kHz were measured in a sound-treated chamber using a modified Hughson-Westlake procedure with a 5 dB step size. Testing began with an ear and test frequency selected at random; the subsequent test frequencies were randomly selected. After acquisition of hearing threshold data at all frequencies, the other ear was tested using the same procedure. After the first HFPTA test, the headphones were removed and carefully replaced. A second HFPTA test was performed with the ear order reversed. The order of testing the ear for the next participant was reversed. Results: Good test–retest reliability of HFPTA was achieved with no significant difference in mean HFPTA thresholds across test and retest conditions for all age groups. An age effect in the test–retest reliability of HFPTA was evident with the 4- to 6-yr-old, 7- to 9-yr-old, and 10- to 13-yr-old children demonstrating normal variability of thresholds (within ±10 dB) in 89.9%, 93.0%, and 97% of ears tested, respectively. When the variability of test–retest thresholds was assessed at each frequency, the 4 to 6 yr group showed significantly lower percentage of normal variability at 14 kHz. In identifying significant deterioration of hearing thresholds across test–retest conditions in relation to the ASHA (1994) ototoxicity criteria, the three age groups (youngest to oldest) demonstrated false-positive rates of 24.6%, 11%, and 7.6%, respectively. Conclusion: Overall, this study demonstrated high test–retest reliability of HFPTA in all but the 4 to 6 yr group. With a false-positive rate of 24.6% for ototoxicity for the youngest group, it is recommended that the HFPTA should not be used alone in assessing the possibility of a genuine threshold shift for this age group. If possible, the HFPTA should be supplemented with an objective test of auditory function to confirm the diagnosis. For children aged 7 yr or older, the HFPTA test is promising as a useful tool to identify hearing impairment in the extended high-frequency range (>8 kHz). However, interpretation of HFPTA findings in serial testing for monitoring hearing in a child should be made with due attention being given to the frequency of the stimulus, age of the child, and the associated nonzero false-positive rates.

Normative wideband reflectance measures in healthy neonates

OBJECTIVE Presently, normative wideband reflectance data are available for neonates who have passed a distortion product otoacoustic emission test. However, passing the distortion product otoacoustic emission test alone does not ensure normal middle ear function. The objective of this study was to establish normative wideband reflectance data in healthy neonates with normal middle ear function, as justified by passing a battery of tests. METHOD Wideband reflectance was measured in 66 infants (mean age=46.0 h, SD=21.0, range=13.3-116.5h) who passed a test battery that included high frequency (1000 Hz) tympanometry, acoustic stapedial reflex, transient evoked otoacoustic emissions and distortion product otoacoustic emissions. RESULTS The analysis of variance (ANOVA) results showed significant variations of reflectance across the frequencies. There was no significant difference between ears and genders. The median reflectance reached a minimum of 0.21-0.24 at 1-2 kHz, but increased to 0.45-0.59 below 1 kHz and 0.24-0.52 above 2 kHz. CONCLUSIONS The normative reflectance data established in the present study were in agreement with, but marginally smaller than, those of previous normative studies, except for the Keefe et al. (2000) study. While the use of a test battery approach to ensure normal middle ear function in neonates has resulted in slightly reduced reflectance across most frequencies when compared to studies that have used only otoacoustic emissions, further research is needed to accurately determine the middle ear status of neonates using test performance measures.

Conductive Hearing Loss and Middle Ear Pathology in Young Infants Referred through a Newborn Universal Hearing Screening Program in Australia

BACKGROUND Although newborn hearing screening programs have been introduced in most states in Australia, the prevalence of conductive hearing loss and middle ear pathology in the infants referred through these programs is not known. PURPOSE This study was designed to (1) evaluate the prevalence of conductive hearing loss and middle ear pathology in infants referred by a newborn hearing screening program in north Queensland, (2) compare prevalence rates of conductive hearing loss and middle ear pathology in indigenous and nonindigenous infants, and (3) review the outcomes of those infants diagnosed with conductive hearing loss and middle ear pathology. RESEARCH DESIGN Retrospective chart review of infants referred to the Audiology Department of The Townsville Hospital was conducted. STUDY SAMPLE Chart review of 234 infants referred for one or both ears from a newborn hearing screening program in north Queensland was conducted. A total of 211 infants attended the diagnostic appointment. Review appointments to monitor hearing status were completed for 46 infants with middle ear pathology or conductive hearing loss. DATA COLLECTION AND ANALYSIS Diagnosis of hearing impairment was made using an age-appropriate battery of audiological tests. Results were analyzed for both initial and review appointments. RESULTS Mean age at initial diagnostic assessment was 47.5 days (SD = 31.3). Of the 69 infants with middle ear pathology during initial diagnostic assessment, 18 had middle ear pathology with normal hearing, 47 had conductive hearing loss, and 4 had mixed hearing loss. Prevalence of conductive hearing loss in the newborns was 2.97 per 1,000 while prevalence of middle ear pathology (with or without conductive hearing loss) was 4.36 per 1,000. Indigenous Australians or Aboriginal and Torres Strait Islander (ATSI) infants had a significantly higher prevalence of conductive hearing loss and middle ear pathology than non-ATSI infants (35.19 and 44.45% vs 17.83 and 28.66%, respectively). ATSI infants also showed poor resolution of conductive hearing loss over time with 66.67% of ATSI infants reviewed showing persistent conductive hearing loss compared to 17.86% of non-ATSI infants. Medical management of 17 infants with persistent conductive hearing loss included monitoring, antibiotic treatment, examination under anesthesia, and grommet insertion. CONCLUSIONS Conductive hearing loss was found to be a common diagnosis among infants referred through screening. ATSI infants had significantly higher rates of middle ear pathology and conductive hearing loss at birth and showed poor resolution of middle ear pathology over time compared to non-ATSI infants. Future research using a direct measure of middle ear function as an adjunct to the automated auditory brainstem response screening tool to distinguish conductive from sensorineural hearing loss may facilitate prioritization of infants for assessment, thus reducing parental anxiety and streamlining the management strategies for the respective types of hearing loss.

Children with minimal conductive hearing impairment: speech comprehension in noise.

Based on a study sample of 1071 primary school children (5.3–11.7 years), 10.2% of the children were found to have conductive hearing loss in 1 or both ears. Binaural speech comprehension scores of a subset of 540 children were analyzed. The results showed that children with bilateral conductive hearing loss had the lowest mean scores of 60.8–69.3% obtained under noise conditions. These scores were significantly lower than the corresponding scores of 69.3–75.3% obtained by children with possible middle ear disorders but no apparent hearing loss, 70.5–76.5% obtained by children with a unilateral conductive hearing loss and 72.0–80.3% obtained by their normally hearing peers. This study confirms that young children, who are known to have poorer speech understanding in noise, show further disadvantage when a bilateral conductive hearing loss is present.

Wideband absorbance in young infants (0-6 months): a cross-sectional study.

BACKGROUND Wideband acoustic immittance (WAI) studies on infants have shown changes in WAI measures with age. These changes are attributed, at least in part, to developmental effects. However, developmental effects in young infants (0-6 mo) on WAI have not been systematically investigated. PURPOSE The objective of this study was to compare wideband absorbance (WBA) in healthy neonates and infants aged 1, 2, 4, and 6 mo. RESEARCH DESIGN This was a prospective cross-sectional study. All participants were assessed by using 1-kHz tympanometry, distortion product otoacoustic emission (DPOAE) tests, and WBA tests. STUDY SAMPLE Participants included 35 newborns (35 ears), 16 infants aged 1 mo (29 ears), 16 infants aged 2 mo (29 ears), 15 infants aged 4 mo (28 ears), and 14 infants aged 6 mo (27 ears). For each participant, the ears that passed both high-frequency (1-kHz) tympanometry and DPOAE tests were included for analysis. DATA COLLECTION AND ANALYSIS WBA was recorded at ambient pressure conditions, and the response consisted of 16 data points at 1/3-octave frequencies from 0.25 to 8 kHz. A mixed-model analysis of variance (ANOVA) was applied to the data in each age group to evaluate the effects of sex, ear, and frequency on WBA. WBA was compared between various age groups. In addition, a separate mixed-model ANOVA was applied to WBA data, and post hoc analyses with the Bonferroni correction were performed at each of the 16 data points at 1/3-octave frequencies across age groups to examine the effect of age on WBA. RESULTS For all age groups, WBA was highest between 1.5 and 5 kHz and lowest at frequencies of less than 1.5 kHz and greater than 5 kHz. A developmental trend was evident, with both the 0- and 6-mo-old infants being significantly different from other age groups at most frequencies. The WBA results exhibited a multipeaked pattern for infants aged 0 to 2 mo, whereas a single broad peaked pattern for 4- and 6-mo-old infants was observed. The difference in WBA between 0- and 6-mo-old infants was statistically significant across most frequencies. In contrast, the WBA results for 1- and 2-mo-old infants were comparable. There were no significant sex or ear effects on WBA for all age groups. CONCLUSIONS Developmental effects of WBA were evident for infants during the first 6 mo of life. The WBA data can be used as a reference for detecting disorders in the sound-conductive pathways (outer and middle ear) in young infants. Further development of age-specific normative WBA data in young infants is warranted.

Transient evoked otoacoustic emissions in children studying in special schools

OBJECTIVES The present study aimed to investigate the feasibility and practicalities of testing children in special school settings using transient evoked otoacoustic emissions (TEOAE) and tympanometry. Children studying in special schools, particularly those with intellectual impairment, may be highly susceptible to hearing pathologies and can be difficult to assess using traditional test batteries. Researchers have recently suggested the possible applicability of TEOAE testing, in lieu of conventional behavioral methods, as a hearing screening device for persons with intellectual impairment. However, to date, few publications have detailed the particulars and results of such testing. METHODS A total of 489 children, with a mean age of 9.6 years, were tested in 15 special schools. Case information was obtained regarding birth history, medical history and type/degree of impairment, for later comparison with screening results. TEOAEs were collected using Quickscreen mode of the ILO292 Otodynamics Analyzer, whilst tympanometry was performed utilizing a Madsen Zodiac 901 Middle Ear Analyzer. RESULTS In total, 80% of students were able to be tested using TEOAEs. Average test time per ear was 2 min. However, a large proportion (40% of those able to be tested) failed TEOAE testing in at least one ear. No significant effects were found between could-not-test (CNT) cases and case history factors. A significant difference in TEOAE failure rates was found across history of neonatal special care nursery residency and history of parental concern regarding possible hearing impairment. Failure rates were higher for those who indicated positive histories. A total of 74% of subjects could be tested using tympanometry, with 25% of those able to be tested failing in at least one ear. Notably, neither type nor degree of impairment had any significant bearing on CNT or failure rates for tympanometry or TEOAE screening. CONCLUSIONS Findings of the present investigation lend support to the review of hearing screening programs for children in special schools, with TEOAEs presenting as a potential alternative procedure. Further examination of the performance measures of protocols incorporating TEOAEs would now be advantageous.