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Objective To evaluate the association between craniofacial phenotype and hearing loss in children with craniofacial microsomia. Design Retrospective cohort study. Setting Tertiary care children's hospital. Patients Individuals with craniofacial microsomia. Main Outcome Measures Ear-specific audiograms and standardized phenotypic classification of facial characteristics. Results A total of 79 participants were included in the study. The mean age was 9 years (range, 1 to 23 years) and approximately 60% were boys. Facial anomalies were bilateral in 39 participants and unilateral in 40 participants (24 right, 16 left). Microtia (hypoplasia of the ear) was the most common feature (94%), followed by mandibular hypoplasia (76%), soft tissue deficiency (60%), orbital hypoplasia or displacement (53%), and facial nerve palsy (32%). Sixty-five individuals had hearing loss (12 bilateral and 53 unilateral). Hearing loss was conductive in 73% of affected ears, mixed in 10%, sensorineural in 1%, and indeterminate in 16%. Hypoplasia of the ear or mandible was frequently associated with ipsilateral hearing loss, although contralateral hearing loss occurred in 8% of hemifaces. Conclusions Hearing loss is strongly associated with malformations of the ipsilateral ear in craniofacial microsomia and is most commonly conductive. Hearing loss can occur contralaterally to the side with malformations in children with apparent hemifacial involvement. Children with craniofacial microsomia should receive early diagnostic hearing assessments.

Background: Children with steeply sloping sensorineural hearing loss (SNHL) lack access to critical high-frequency cues despite the use of advanced hearing aid technology. In addition, their auditory-only aided speech perception abilities often meet Food and Drug Administration criteria for cochlear implantation. Purpose: The objective of this study was to describe hearing preservation and speech perception outcomes in a group of young children with steeply sloping SNHL who received a cochlear implant (CI). Research Design: Retrospective case series. Study Sample: Eight children with steeply sloping postlingual progressive SNHL who received a unilateral traditional CI at Seattle Children’s Hospital between 2009 and 2013 and had follow-up data available up to 24 mo postimplant were included. Data Collection and Analysis: A retrospective chart review was completed. Medical records were reviewed for demographic information, preoperative and postoperative behavioral hearing thresholds, and speech perception scores. Paired t tests were used to analyze speech perception data. Hearing preservation results are reported. Results: Rapid improvement of speech perception scores was observed within the first month postimplant for all participants. Mean monosyllabic word scores were 76% and mean phoneme scores were 86.7% at 1-mo postactivation compared to mean preimplant scores of 19.5% and 31.0%, respectively. Hearing preservation was observed in five participants out to 24-mo postactivation. Two participants lost hearing in both the implanted and unimplanted ear, and received a sequential bilateral CI in the other ear after progression of the hearing loss. One participant had a total loss of hearing in only the implanted ear. Results reported in this article are from the ear implanted first. Bilateral outcomes are not reported. Conclusions: CIs provided benefit for children with steeply sloping bilateral hearing loss for whom hearing aids did not provide adequate auditory access. In our cohort, significant improvements in speech understanding occurred rapidly postactivation. Preservation of residual hearing in children with a traditional CI electrode is possible.

Objective The goal of this study was to estimate psychophysical levels using the electrically evoked compound action potential (EAP), measured with the Neural Response Telemetry capabilities of Cochlear Corporation's Nucleus CI24M cochlear implant system. Design Twelve postlingually deafened adults with at least 3 mo of implant experience with the CI24M were subjects in this study. EAP growth functions were successfully quantified on each active electrode of every subject. Correlation and regression analyses were performed between EAP measures and cochlear implant fitting psychophysics. Other information including performance, etiology and duration of hearing loss, and individual electrode impedance was considered. Results EAP thresholds were found to be highly correlated with psychophysical thresholds. The rate of EAP growth with increasing stimulation levels was also found to be correlated with the dynamic range of loudness limits and psychophysical thresholds in some subjects. No relationship was evident between EAP measures and speech perception tests. Conclusions Information from EAP growth function measurements may be used to estimate psychophysical information used in cochlear implant fitting but not to predict performance with the device.

The deafwaddler ( dfw ) mouse mutant is caused by a spontaneous mutation in the gene that encodes a plasma membrane Ca 2+ ATPase (type 2), PMCA2 (Street et al., 1998. Nat. Genet. 19, 390–394), which is expressed in cochlear and vestibular hair cells. Distortion product otoacoustic emission (DPOAE) amplitudes and latencies were examined in control mice, deafwaddler mutants, and controls treated with the drug furosemide. Furosemide causes a transient reduction of DPOAEs (Mills et al., 1993. J. Acoust. Soc. Am. 94, 2108–2122). We wanted to determine whether DPOAEs obtained in furosemide-treated mice were similar or different from results obtained in +/ dfw mice. DPOAE amplitude and phase were measured as a function of f 2 / f 1 ratio. These data were converted into waveforms using inverse fast Fourier transform, and their average latency was used to estimate DPOAE group delay. Homozygous deafwaddlers did not produce DPOAEs. Heterozygous deafwaddlers (+/ dfw ) had increased DPOAE thresholds and reduced amplitudes at high frequencies, compared to controls. To the extent that DPOAEs depend on functional outer hair cells (OHCs), abnormal DPOAEs in +/ dfw mice suggest that PMCA2 is important for OHC function at high frequencies. Similar to the effects of furosemide, the mutation reduced DPOAEs for low-level stimuli; in contrast to furosemide, the mutation altered DPOAEs elicited by high levels.

This article describes the audiologic findings and medical status of infants who were found to have hearing loss, detected as part of the Identification of Neonatal Hearing Impairment (INHI) project. In addition, the neonatal and maternal health variables for the group of infants who could not be tested with visual reinforcement audiometry (VRA) due to developmental and visual disability are presented.The overall goal of the INHI project was to evaluate the test performance of auditory brain stem response and evoked otoacoustic emission (OAE) tests given in the newborn period. These tools were evaluated on the basis of the infants' hearing when tested behaviorally with VRA at 8 to 12 mo corrected age. The neonatal test results, VRA results, medical history information and a record of intercurrent events occurring between the neonatal period and the time of VRA were collated and reviewed. The purpose of this article is to review the characteristics of those infants who were found to have hearing loss.Of 2995 infants who had VRA tests judged to be of good or fair reliability, 168 had a finding of hearing loss for at least one ear, an incidence of 5.6%. Sixty-six infants had bilateral losses, an incidence of 2%, and 22 infants had bilateral hearing losses in the moderate to profound range, an incidence 0.7%. The prevalence of middle ear problems was greater than 50% among these infants with hearing loss. From the larger group of 168 infants with hearing loss, a group of 56 infants (86 ears) was chosen as those with a low probability that the hearing loss was due to transient middle ear pathology and was more likely hearing loss of a permanent nature. These were the infants used for the analyses of neonatal test performance (Norton et al., 2000). In this selected group there were 30 infants with bilateral impairment of at least mild degree, which is an incidence of 1%. There were approximately equal numbers of ears in the mild, moderate, severe and profound range of hearing loss. Risk factors associated with hearing loss were reviewed for the total sample of infants tested with VRA and for those infants with hearing loss. A history of treatment with aminoglycosides was the risk factor most often reported in the entire sample; however, there was no difference in prevalence of this risk factor for the normal-hearing and hearing-impaired groups. The risk factor associated with the highest incidence of hearing loss was stigmata of syndromes associated with sensorineural hearing loss and other neurosensory disorders. Sixty-seven infants who returned for follow-up could not be tested with VRA due to severe developmental delay or visual disability. Many of these infants had medical histories indicating the sequelae of extreme prematurity and/or very low birthweight.Most of the hearing losses found in this study were mild and, based on clinical history and tympanometry tests, many of the mild and some of the moderate impairments may have been acquired in early infancy due to middle ear effusion. In the group of infants used for determination of neonatal test performance there were approximately equal numbers of mild, moderate, severe and profound losses. Only a small percentage of infants with a conventional risk indicator for hearing loss actually had a hearing loss, and there were a significant number of infants with hearing loss who did not have a risk indicator. These findings support the need for an early identification program based on universal neonatal hearing screening rather than by targeted testing of those with risk indicators.

The purpose of this study was to compare the performance of transient evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), and auditory brain stem responses (ABRs) as tools for identification of neonatal hearing impairment.A total of 4911 infants including 4478 graduates of neonatal intensive care units, 353 well babies with one or more risk factors for hearing loss (Joint Committee on Infant Hearing, 1994) and 80 well babies without risk factor who did not pass one or more neonatal test were targeted as the potential subject pool on which test performance would be assessed. During the neonatal period, they were evaluated using TEOAEs in response to an 80 dB pSPL click, DPOAE responses to two stimulus conditions (L1 = L2 = 75 dB SPL and L1 = 65 dB SPL L2 = 50 dB SPL), and ABR elicited by a 30 dB nHL click. In an effort to describe test performance, these "at-risk" infants were asked to return for behavioral audiologic assessments, using visual reinforcement audiometry (VRA) at 8 to 12 mo corrected age, regardless of neonatal test results. Sixty-four percent of these subjects returned and reliable VRA data were obtained on 95.6% of these returnees. This approach is in contrast to previous studies in which, by necessity, efforts were made to follow only those infants who "failed" the neonatal screening tests. The accuracy of the neonatal measures in predicting hearing status at 8 to 12 mo corrected age was determined. Only those infants who provided reliable, monaural VRA test results were included in the analysis. Separate analyses were performed without regard to intercurrent events (i.e., events between the neonatal and VRA tests that could cause their results to disagree), and then after accounting for the possible influence of intercurrent events such as otitis media and late-onset or progressive hearing loss.Low refer rates were achieved for the stopping criteria used in the present study, especially when a protocol similar to the one recommended in the National Institutes of Health (1993) Consensus Conference Report was followed. These analyses, however, do not completely describe test performance because they did not compare neonatal screening test results with a gold standard test of hearing. Test performance, as measured by the area under a relative operating characteristic curve, were similar for all three neonatal tests when neonatal test results were compared with VRA data obtained at 8 to 12 mo corrected age. However, ABRs were more successful at determining auditory status at 1 kHz, compared with the otoacoustic emission (OAE) tests. Performance was more similar across all three tests when they were used to identify hearing loss at 2 and 4 kHz. No test performed perfectly. Using either the two- or three-frequency pure-tone average (PTA), with a fixed false alarm rate of 20%, hit rates for the neonatal tests, in general, exceeded 80% when hearing impairment was defined as behavioral thresholdsor =30 dB HL. All three tests performed similarly when a two-frequency (2 and 4 kHz) PTA was used as the gold standard; OAE test performance decreased when a three-frequency PTA (adding 1 kHz) was used as the gold standard definition. For both PTA and all three neonatal screening measures, however, hit rate increased as the magnitude of hearing loss increased.Singly, all three neonatal hearing screening tests resulted in low refer rates, especially if referrals for follow-up were made only for the cases in which stopping criteria were not met in both ears. Following a protocol similar to that recommended in the National Institutes of Health (1993) Consensus Conference report resulted in refer rates that were less than 4%. TEOAEs at 80 dB pSPL, DPOAE at L1 = 65, L2 = 50 dB SPL and ABR at 30 dB nHL measured during the neonatal period, and as implemented in the current study, performed similarly at predicting behavioral hearing status at 8 to 12

The objective of this study was to describe the demographic data, medical status, and incidence of risk factors for hearing impairment in the neonatal intensive care unit (NICU) and well-baby populations in a multicenter prospective study designed to assess neonatal hearing impairment and to evaluate factors that might affect neonatal hearing test performance.This was a prospective multicenter study funded by the National Institutes of Health-National Institute on Deafness and Other Communication Disorders to evaluate the effectiveness of auditory brain stem response, transient evoked otoacoustic emissions, and distortion product otoacoustic emissions for newborn hearing screening. Research staff at each site obtained informed consent and detailed demographic and medical data, including information on established risk factors for hearing loss on 4478 high-risk infants cared for in the NICU, 2348 infants from the well-baby nurseries with no risk factor, and 353 infants from the well-baby nurseries with risk factors. For follow-up purposes the sample was divided further to include a subgroup called selects. Selects were either infants from the well-baby nursery who had an established risk factor for hearing impairment (N = 353) or did not pass the neonatal hearing screen protocol (N = 80). In this study, we focus on the distribution of infants by nursery and risk factors only. Particular effort was made to enroll infants with risk factors for hearing loss in both the NICU and well-baby nurseries. Descriptive analyses are used to describe characteristics of this sample.All 10 of the risk factors established by the Joint Committee on Infant Hearing in 1994 were identified in the NICU population. The four most common were ototoxic medications (44.4%), very low birth weight (17.8%), assisted ventilation5 days (16.4%), and low Apgar scores at 1 or 5 min (13.9%). In contrast, only six risk factors were present in the well-baby nurseries: family history (6.6%), craniofacial abnormalities (3.4%), low Apgar scores (2.8%), syndromes (0.5%), ototoxic medications (0.2%), and congenital infection (0.1%).These descriptive risk factor data reflect both the newborn populations at the study sites and the bias for enrolling infants at risk for hearing loss. The high-risk NICU sample reflects the characteristics typically found in graduates of the NICU. The data summarized in this study will be used to assess the relationships between risk factor and hearing test outcome.

Objectives 1) To describe the auditory brain stem response (ABR) measurement system and optimized methods used for study of newborn hearing screening. 2) To determine how recording and infant factors related to the screening, using well-defined, specific ABR outcome measures. Design Seven thousand one hundred seventy-nine infants, 4478 from the neonatal intensive care unit (NICU) and the remaining from the well-baby nursery, were evaluated with an automated ABR protocol in each ear. Two channel recordings were obtained (vertex to mastoid or channel A and vertex to nape of neck or channel B) in response to click stimuli of 30 and 69 dB nHL in all infants as well as 50 dB nHL in infants who did not meet criteria for response at 30 dB. Criteria for response included F(SP) > or =3.1 and a tester-judgment of response. Criteria could be met in the first or repeat test with a maximum of 6144 accepted sweeps per test. Results More than 99% of infants could complete the ABR protocol. More than 90% of NICU and well-baby nursery infants "passed" given the strict criteria for response, whereas 86% of those with high risk factors met criterion for ABR response detection. The number of infants who did not meet ABR response criteria in one or both ears was systematically related to stimulus level with the largest group not meeting criteria at 30 dB followed by 50 and 69 dB nHL. Meeting criteria on the ABR was positively correlated with the amplitude of wave V, with low noise and low electrode impedance. Factors that predicted how many sweeps would be needed to reach criterion F(SP) included noise level of the test site, state of the baby (for example, quiet sleep versus crying), recording noise, electrode impedance and response latency. Channel A (vertex to mastoid) reached criterion more often than channel B (vertex to nape of neck) due to higher noise in channel B. Average total test time for 30 dB nHL screening in both ears was under 8 minutes. Well babies with risk factors took slightly longer to evaluate than other groups with this automated ABR procedure and have higher noise levels. Conclusions ABR implemented with an automated detection algorithm using a 30 dB nHL click stimulus is reliable technique for rapid assessment of auditory status in newborns. Factors other than hearing loss that influenced the test result include infant state, electrode location and impedance, testing site, and infant risk status. Even so, ABRs were reliably recorded in the vast majority of babies under circumstances in which most babies are found in the perinatal period.

1) To describe the hearing status of the at-risk infants in the National Institutes of Health-Identification of Neonatal Hearing Impairment study sample at 8 to 12 mo corrected age (chronologic age adjusted for prematurity). 2) To describe the visual reinforcement audiometry (VRA) protocol that was used to obtain monaural behavioral data for the sample.All neonatal intensive care unit infants and well babies with risk factors (including well babies who failed neonatal tests) were targeted for follow-up behavioral evaluation once they had reached 8 mo corrected age. Three thousand one hundred and thirty-four (64.4%) of the 4868 surviving infants returned for at least one behavioral hearing evaluation, which employed a well-defined VRA protocol. VRA thresholds or minimum response levels (MRLs) were determined for speech and pure tones of 1.0, 2.0, and 4.0 kHz for each ear using insert earphones.More than 95% of the infants were reliably tested with the VRA protocol; 90% provided complete tests (four MRLs for both ears). Ninety-four percent of the at-risk infants were found to have normal hearing sensitivity (MRLs of 20 dB HL) at 1.0, 2.0, and 4.0 kHz in both ears. Of the infants, 2.2% had bilateral hearing impairment, and 3.4% had impairment in one ear only. More than 80% of the impaired ears had losses of mild-to-moderate degree.This may be the largest study to attempt to follow all at-risk infants with behavioral audiometric testing, regardless of screening outcome, in an effort to validate the results of auditory brain stem response, distortion product otoacoustic emission, and transient evoked otoacoustic emission testing in the newborn period. It is one of only a few studies to report hearing status of infants at 1 yr of age, using VRA on a clinical population. Successful testing of more than 95% of the infants who returned for the VRA follow-up documents the feasibility of obtaining monaural behavioral data in this population.

Objectives: 1) To describe distortion product otoacoustic emission (DPOAE) levels, noise levels and signal to noise ratios (SNRs) for a wide range of frequencies and two stimulus levels in neonates and infants. 2) To describe the relations between these DPOAE measurements and age, test environment, baby state, and test time. Design: DPOAEs were measured in 2348 well babies without risk indicators, 353 well babies with at least one risk indicator, and 4478 graduates of neonatal intensive care units (NICUs). DPOAE and noise levels were measured at f 2 frequencies of 1.0, 1.5, 2.0, 3.0, and 4.0 kHz, and for primary levels (L 1 /L 2 ) of 65/50 dB SPL and 75/75 dB SPL. Measurement-based stopping rules were used such that a test did not terminate unless the response was at least 3 dB above the mean noise floor + 2 SDs (SNR) for at least four of five test frequencies. The test would terminate, however, if these criteria were not met after 360 sec. Baby state, test environment, and other test factors were captured at the time of each test. Results: DPOAE levels, noise levels and SNRs were similar for well babies without risk indicators, well babies with risk indicators, and NICU graduates. There was a tendency for larger responses at f 2 frequencies of 1.5 and 2.0 Hz, compared with 3.0 and 4.0 kHz; however, the noise levels systematically decreased as frequency increased, resulting in the most favorable SNRs at 3.0 and 4.0 kHz. Response levels were least and noise levels highest for an f 2 frequency of 1.0 kHz. In addition, test time to achieve automatic stopping criteria was greatest for 1.0 kHz. With the exception of active/alert and crying babies, baby state had little influence on DPOAE measurements. Additionally, test environment had little impact on these measurements, at least for the environments in which babies were tested in this study. However, the lowest SNRs were observed for infants who were tested in functioning isolettes. Finally, there were some subtle age affects on DPOAE levels, with the infants born most prematurely producing the smallest responses, regardless of age at the time of test. Conclusions: DPOAE measurements in neonates and infants result in robust responses in the vast majority of ears for f 2 frequencies of at least 2.0, 3.0 and 4.0 kHz. SNRs decrease as frequency decreases, making the measurements less reliable at 1.0 kHz. When considered along with test time, there may be little justification for including an f 2 frequency at 1.0 kHz in newborn screening programs. It would appear that DPOAEs result in reliable measurements when tests are conducted in the environments in which babies typically are found. Finally, these data suggest that babies can be tested in those states of arousal that are most commonly encountered in the perinatal period.

OBJECTIVE Transient evoked otoacoustic emissions (TEOAEs) were measured in children with normal hearing and in children with hearing loss to investigate the characteristics of TEOAEs as they relate to overall amplitude and amplitude spectra of evoking stimuli, and to audiometric status. DESIGN Three parameters of response measure (signal to noise ratio, amplitude and reproducibility) were assessed to determine accuracy of identification of varying degrees of hearing loss for broadband clicks, frequency-specific click bands and tone bursts. Forty-four children (66 ears) between 4 and 13 yr of age were evaluated for participation in the study. Fifty-nine ears with intact tympanic membranes were included in the final analyses: 14 ears with normal hearing and 45 ears with hearing loss. RESULTS Children with normal hearing had robust responses that displayed nonlinear growth functions for broadband clicks and for tone bursts. Children with hearing loss had responses that decreased rapidly with decreasing stimulus level, if emissions were present at all. Data were analyzed using clinical decision analysis and receiver operator characteristic curves. Broadband clicks presented at 80 and 86 dB peSPL identified a hearing loss > or = 30 dB HL with a high degree of accuracy. Click responses filtered into octave bands centered at 500 and 1000 Hz did not improve classification of hearing loss, in fact, the 500 Hz band was particularly inaccurate. Results for click responses filtered into half-octave bands centered at 2000 and 4000 Hz were comparable with those for the broadband click, although the 2000 Hz band was superior for identification of hearing loss > or = 20 dB HL for an 80 dB peSPL click, and > or = 30 dB HL for an 86 dB peSPL click. Results for tone bursts centered at 500, 1000, 2000 and 4000 Hz, presented at 80 dB peSPL, were similar to results of the filtered click bands. Accuracy for identifying hearing loss increased with increasing center frequency. The 2000 and 4000 Hz tone bursts provided the best separation between normal-hearing and hearing-impaired ears, with 4000 Hz being slightly better. CONCLUSIONS Data from this study suggest that TEOAEs in children can separate ears with normal hearing from those with hearing loss using a variety of stimulus and response conditions. Moreover, by using multiple stimulus levels it may be possible to distinguish between mild and moderate hearing losses.

Ototoxicity associated with cis-platinum administration commonly presents as hearing loss and tinnitus. The hearing loss is usually an irreversible, high-frequency sensorineural loss. Histologic studies in humans and animals suggest that the outer hair cells (OHCs) are most susceptible to cis-platinum. Evoked otoacoustic emissions (EOAE), as a measure of outer hair cell function, are potentially useful in following ototoxic insults involving OHCs. Distortion-product otoacoustic emissions (DPOAE) test frequency-specific regions of the cochlea and therefore may be particularly well suited for monitoring ototoxic injuries. We measured distortion product otoacoustic emissions, at f2 = 2, 4, 6, 8, 10, and 12 kHz, in gerbils after a single large dose of cis-platinum. Animals treated with saline served as controls. The findings were compared to auditory brain stem evoked response (ABR) thresholds, using tone pips of the same frequencies. The DPOAE and ABR thresholds were measured before treatment and again 2, 5, and 14 days after drug administration. The changes in DPOAE were compared with the changes in ABR. No treatment effect was noted in the 2-day group. Animals treated with c/s-platinum demonstrated significant elevation of DPOAE and ABR thresholds compared with control animals at 5 and 14 days. There was no significant difference between the threshold changes in the 5-and 14-day groups.

Distortion product otoacoustic emissions (DPOAE) were measured serially in guinea pigs before and following 4-h exposures to a half-octave band of noise centered at 6 kHz. Stimulus parameters used to elicit the DPOAE were f2/f1 = 1.26 and L2 = L1-10. The 80 dB SPL exposures resulted in attenuation of emissions, which was maximal at the frequency one-half octave above the exposure when referenced to the f2 stimulus, and which recovered back to baseline after 2 days. The 90 dB SPL exposures resulted in a permanent deficit in emissions elicited by high-frequency stimuli, as measured after 8 days of recovery. A statistically significant difference was also found between animals exposed continuously for 4 h versus animals given two 2-h exposures separated by a 1-h break. Measures of f2-f1 and 3f1-2f2 indicated that they were more sensitive than 2f1-f2 to alterations in cochlear function after noise exposure.

Objectives: To determine hearing loss prevalence among a group of Third World children, to describe the physical examination and audiometric findings in the hearing-impaired children, and to assess the association of hearing loss with several known risk factors. It was hypothesized that chronic otorrhea would be the risk factor most strongly associated with hearing loss. Design: Community screening program to identify and evaluate hearing-impaired children. Case-control analysis of hearing loss risk factors. A survey taker, blinded to the children's hearing status, ascertained risk factors. Setting: Rural community in eastern province of Sierra Leone, West Africa. Patients: Population-based sample of 2015 children aged 5 to 15 years. Risk factor analysis was performed in 184 children and an equal number of matched controls. Main Outcome Measure: Hearing loss determined according to World Health Organization, Geneva, Switzerland, definition. Results: A total of 184 (9.1%) of 2015 children were found to have mild or greater hearing loss. The prevalence of bilateral profound hearing impairment was 4.0 per 1000. We assessed physical examination and audiometric findings. The risk factor most strongly associated with hearing loss was a history of otorrhea persisting longer than 1 month (odds ratio, 23.3; 95% confidence limits, 12.11, 45.40). Conclusions: A high prevalence of hearing loss was identified. Much of this impairment may result from chronic untreated or unrecognized ear infections. Further community-based studies of hearing-impaired children are necessary for planning preventive and curative programs. (Arch Otolaryngol Head Neck Surg. 1995;121:853-858)

Evoked otoacoustic emissions (EOAEs) are a promising tool for evaluating cochlear status in children. Preliminary data from normal-hearing subjects ranging from birth to 29.9 years old are discussed. EOAEs are present and robust in infant ears. However, there is a statistically significant decrease in EOAE amplitude for a fixed stimulus level with increasing age even in a carefully screened sample. At the present time it is unclear if these age-associated changes are due to normal developmental changes in the external and/or middle ear acoustics, normal developmental changes in cochlear mechanics and/or everyday cochlear wear and tear. Issues related to further application of evoked emissions to pediatric populations are discussed.

Objectives/Hypothesis: Congenital severe to profound sensorineural hearing loss (SNHL) is found in higher proportions of children with minority and/or lower socioeconomic status (SES). Cochlear implants were approved by the U.S. Food and Drug Administration for use in children with bilateral severe to profound SNHL in 1990. The objectives of the study were as follows: 1) to study the epidemiology of pediatric cochlear implantation, assessing whether cochlear implant technology is provided to children with severe to profound SNHL in proportion to their racial/ethnic or SES, and 2) to compare data provided by a national health care database with data provided by cochlear implant manufacturers. Study Design: Patients aged 0 to 18 years who underwent cochlear implantation in 1997 using a cross-sectional study design. Methods: Analyses were made of pediatric cochlear implant patients, using data from the 1997 Health Care and Utilization Project/Kids' Inpatient Database. Relative rates of implantation compared with rates of severe to profound SNHL were calculated using national estimates generated from census and Galludet Research Institution data. Logistic regression analysis was carried out to compare implanted children of different racial/ethnic backgrounds. A surrogate measure of socioeconomic status was used based on the median household income of the patient's home ZIP code. Information was also obtained from the two companies producing U.S. Food and Drug Administration–approved cochlear implants in 1997 and used to determine whether the data obtained from the Health Care and Utilization Project/Kids' Inpatient Database were representative of the national cohort of implanted children. Results: The Health Care and Utilization Project/Kids' Inpatient Database identified 124 children who underwent cochlear implant surgery in 1997. White and Asian children were implanted at higher rates than Hispanic and black children. Furthermore, white and Asian children received implants at greater rates than would be expected based on prevalence of severe to profound SNHL. The relative rate (RR) of implantation, defined as the proportion of children who received cochlear implants divided by the proportion of children with severe to profound SNHL (in each race/ethnicity group compared with the same ratio in white children), was similar in white (RR = 1.00) and Asian (RR = 0.93) children but markedly different in Hispanic (RR = 0.28) and black (RR = 0.10) children. Comparison of SES information from the Health Care and Utilization Project/Kids' Inpatient Database population with the manufacturers' database suggested that the Health Care and Utilization Project/Kids' Inpatient Database is representative of all implanted children in the United States. Both sources of information suggested that children receiving cochlear implants in the United States in 1997 resided in above-average SES areas. Conclusion: White and Asian children with severe to profound SNHL had higher proportionate rates of cochlear implantation than black and Hispanic children in 1997. Implanted children were more likely to live in areas (represented by ZIP codes) with higher median incomes. Although there was a disparity in rate of cochlear implantation based on race/ethnicity and surrogate measures of SES, these data did not allow the authors to determine the causes for these differences.

Problem: Pediatric cochlear implant recipients have been historically assessed postoperatively with audiometric testing in a soundproof booth by trained audiologists. Assessment of functional outcome after cochlear implantation must also consider a number of other factors including speech perception, speech intelligibility, mode of communication, educational placement, as well as the social and psychological factors that affect one’s ability to function in the mainstream environment. No uniform tool for assessing effective functional outcome in the daily life of pediatric cochlear implant recipients has been developed. Methods: Using a cross-sectional design, the COCHLEA (Children’s Outcome for Cochlear Implant Hearing, Language, and Environmental Assessment) questionnaire, designed to measure functional outcomes in the pediatric cochlear implant population, was administered. The questionnaire was tested for reliability and validity, while investigating for any possible respondent or administrative burden. The parents of children with cochlear implants completed the questionnaire. The subjects were individuals with nonsyndromic sensorineural hearing loss (SNHL) implanted at Children’s Hospital and Regional Medical Center before 12/31/2001, aged 3–12 years. Implantation must have occurred before age 7. Non-English-speaking children/families were excluded secondary to a lack of resources. Results: Thirty-one patients were enrolled in the study. Preliminary results indicate that absolute scores of this outcome measure correlate with higher global health measures, including the Child Health Questionnaire (CHQ), and predict better audiometric scores. Conclusion: The COCHLEA functional outcome measure appears to be a reliable and valid method for assessing effective cochlear implantation. More research is necessary to determine this questionnaire’s sensitivity to longitudinal change. Significance: The COCHLEA questionnaire represents the first disease-specific functional outcome measure for the pediatric cochlear implant patient population. Ultimately it may be used to compare the effectiveness of cochlear implants and rehabilitation strategies. Support: None reported.

Objective We sought to demonstrate the rate of change in distortion product otoacoustic emission (DPOE) amplitude with age in relation to hearing loss in an unselected adult population. Study design and setting We conducted a cross-sectional observation study involving the Framingham Offspring Cohort. Age changes in DPOE amplitude for frequencies of f2 from 1 to 8 kHz adjusted for pure-tone threshold level were assessed by multivariate linear regression. Results The women showed a mean hearing threshold-adjusted loss in high-frequency DPOE amplitude of 0.6, 2.1, 2.6, and 1.1 dB/per decade at the f2 frequencies of 1, 2, 4, and 8 kHz, respectively. In contrast, the men showed no effect of age on the DPOE amplitude independent of hearing loss. Emissions were reduced or absent in the noise notch frequencies. The rate of change with age in DPOE amplitude was significantly less than the rate of change in pure-tone thresholds in both the men and the women. Conclusion Women lose DPOE amplitude from both age and hearing threshold loss. Men lose more DPOE amplitude than do women, and the loss is proportional to the degree of loss of hearing threshold sensitivity. The differential effect whereby age-related hearing loss affects thresholds more than emissions suggests that strial atrophy may be a pathophysiologic factor. Significance The use of DPOE measures for screening and monitoring cochlear status of adult women should take into account the age, pure-tone thresholds, and noise exposure status of the subjects.

Otoacoustic emissions were measured in 42 normal hearing subjects ranging from 20 to 80 years old. For each subject spontaneous, click-evoked, tone-burst-evoked, stimulus frequency and distortion product emissions were measured across a wide intensity range for frequencies between 1 and 3 kHz. Although there are significant differences between age groups, the results indicate no age effect independent of hearing sensitivity on any type or parameter of otoacoustic emissions (OAE). The effect of increasing age is confounded with the effect of decreasing sensitivity such that post hoc analyses are inadequate to separate the effects of sensitivity and age on otoacoustic emissions. Even within the range of audiometrically normal hearing, OAE characteristics vary with threshold for all age groups. The conclusion is that hearing sensitivity must be included as a controlled variable in order to accurately assess intrinsic aging effects.

• Objective. —Screening auditory status prior to neonatal hospital discharge to identify newborns with severe hearing impairment is an important pediatric care priority. Evoked otoacoustic emission (OAE) testing is a quick noninvasive method. The purpose of this study was to determine the relationship between external auditory canal and middle ear status with click-evoked OAE. It was hypothesized that vernix caseosa, debris in the ear canal, and middle ear fluid contribute to the OAE fail rate. Design. —All neonates had an initial OAE examination. A second investigator, "blinded" to the results, examined all ears otoscopically, cleaned any obstructing debris, and repeated with a second OAE test. Setting. —All neonates were tested in a designated nursery at a mean age of 43±21 hours. Patients. —Forty-one full-term neonates were prospectively enrolled. Intervention. —The ear canals with debris were cleaned under direct vision with a pediatric swab dampened by an alcohol wipe. Outcome Measure —The primary outcome measure was the postcleaning OAE pass rate. Results. —The preotoscopic examination pass rate of 82 ears was 76%. The OAE pass rate improved to 91% after debris removal. Conclusions. —The results indicate that the examination and cleaning of the external ear canal are important components of the neonatal screening process. (Arch Otolaryngol Head Neck Surg.1993;119:276-282)

Transient evoked otoacoustic emissions (TEOAEs) occur after presentation of brief acoustic stimuli such as clicks and tone pips. They represent physiological activity from within the cochlea, specifically from normal functioning outer hair cells. TEOAEs are frequency specific in that their spectra are determined by the spectra of the evoking stimulus and the audiometric configuration. TEOAEs are sensitive to mild to moderate degrees of cochlear hearing loss up to about 40 to 50 dB HL. They can be measured rapidly and noninvasively in infants and children. Among the potential applications in pediatric audiology are screening for hearing impairment in neonates, separating peripheral hearing loss and central auditory dysfunction, and monitoring cochlear status in children receiving ototoxic drugs.

Attempts to identify the mechanisms underlying tinnitus and to develop effective treatments have been frustrating, in part because there are no objective measures of tinnitus. Following Kemp's initial reports of evoked and spontaneous otoacoustic emissions (OAEs), many people hoped that OAEs were an objective correlate of tinnitus. The results of several studies suggest that in about 6 to 12% of normal-hearing persons with tinnitus and spontaneous otoacoustic emissions (SOAEs), the SOAEs are at least partly responsible for the tinnitus. In addition, recent work indicates that some subjects with tinnitus display oscillating or ringing evoked otoacoustic emissions (EOAEs). In these cases, it is hypothesized that the oscillating EOAEs and tinnitus are related to a common underlying pathology rather than the emissions being the source of the tinnitus.

Professor Zwicker immediately appreciated the importance of David Kemp’s discovery of otoacoustic emissions (OAE), and devoted much of his efforts in recent years to their study. OAEs are sounds generated by nonlinear, highly tuned, physiologically vulnerable biomechanical elements within the cochlea. They can be measured in the external ear canal, and thus provide an exquisite noninvasive tool for studying cochlear mechanics, particularly the ‘‘cochlear amplifier,’’ in vivo. There are several OAE phenomena, distinguished primarily by the stimuli used to evoke them. While all OAEs are generally absent if there is a cochlear hearing loss involving absence of outer hair cells, how these phenomena relate to one another and normal cochlear function is not entirely clear. For a given evoking stimulus, OAEs differ in their ‘‘thresholds,’’ growth rate and maximum output across audiologically normal ears. In addition, within an ear there are frequencies and presumably cochlear regions with relatively stronger emi...

There is a growing body of data concerning otoacoustic emissions (OAEs) in newborn infants. Because OAEs are a noninvasive, objective measure of cochlear status and can be measured relatively rapidly many investigators are excited about using OAEs as a screening tool for hearing loss in newborns. Preliminary studies indicate that both transiently evoked and distortion product emissions are robust across a broad frequency range in normally hearing newborns. Also, both are absent in newborns later confirmed to have severe to profound sensorineural hearing loss. However, several questions have arisen concerning their relationship between the evoking stimulus parameters and OAE characteristics in infant versus adult ears, the influence of probe, external and middle ear acoustics on newborn responses, and the most appropriate OAE stimulus and response parameters for hearing loss screening. These issues are particularly relevant to identifying mild to moderate hearing loss and to understanding hearing developme...

The relationship between gap detection, glide discrimination, and identification of synthesized speech stimuli as more like ‘‘say’’ or more like ‘‘stay’’ was investigated in 18 listeners with varying degrees of hearing impairment. Speech stimuli were patterned after Best, Morrongiello, and Robson’s (1981) ‘‘say–stay’’ identification task, which involved the listeners’ use of silent gap (between signal‐to‐noise and vocalic portions of the signals) and first formant onset frequency, both indicating the presence or absence of stop consonants. A significant effect of hearing impairment was found on the gap detection and glide discrimination tasks, and on the identification functions of the ‘‘say–stay’’ stimuli. However, the speech identification functions were not correlated with the psychoacoustic results. In fact, the identification performance suggested listeners with mild to moderate hearing impairments were using weaker spectral cues than the normal‐hearing listeners, which is contradictory to what is pr...

Tone-burst-evoked otoacoustic emissions were measured as a function of tone-burst sound pressure level and frequency in normally hearing ears. Although the spectral and temporal properties varied across individual ears, there was a close correspondence between stimulus and response spectra. Both the spectral and latency characteristics of tone-burst-evoked emissions are consistent with the hypothesis that they are generated at sites along the cochlear partition corresponding to their frequency.

The presence of continuous, narrow‐band acoustic signals (oto‐acoustic emissions) in recordings made from the ear canals of human subjects has been reported by several authors. We report here the results of our attempt to detect such emissions from a series of 92 normally hearing ears from 47 adult subjects. Our results were quite similar to those reported by Zurek [J. Acoust. Soc. Am. 69, 514–523 (1981)]. Emissions were found in 38% of the people and 27% of the ears tested. The distributions of the recorded emissions were also very similar to the results of Zurek’s study.

A comparison of the latency of auditory brain-stem responses (ABR) and evoked otoacoustic emissions (EOAE) has led to an interpretation for the travel of transients in the peripheral auditory system that is consistent with both sets of data. The "cochlear echo" theory for the origin of the EOAE indicates that the latency of a particular frequency component back to the ear canal should be twice the forward latency of its characteristic place in the cochlea. The latency of wave V of the ABR to tone-burst stimuli can be described as the sum of two components: (1) a component that varies with intensity and frequency in an orderly and predictable manner and (2) a component that is independent of both intensity and frequency. Because the EOAE data can be predicted by taking twice the value of component (1) of the ABR latency, this component is interpreted to be due to mechanical travel through the cochlea. A consequence of this interpretation is that the remaining neural component of the ABR latency must be relatively independent of frequency and intensity.

A "selective" hearing screening program was instituted in an early education project. Three-year-old children were deemed "at risk" for mild-to-moderate hearing loss if they met one of the risk criteria established by the Joint Com mittee on Infant Hearing Screening, if they had recurrent ear infections, or if there was parent or staff concern about the child's hearing. Based on these criteria, 31 per cent of the 228 children in the project were eligible for full audiologic evaluation at a speech and hearing center. The parents of 45 chil dren took advantage of this special evaluation. Twenty-nine per cent of these selected children had some hearing loss documented. The highest yields of abnormal hearing were for children "at risk" because of recurrent ear infec tions (42%), and parent or educational staff concern (71%).

Spontaneous otoacoustic emissions (SOAEs) were measured in human ear canals before, during and after presentation of tonal stimuli to the contralateral ear. Stimuli were presented in 1 8 octave steps from 2 octaves below to 1 octave above the SOAE frequency at sound levels below the observed contralateral acoustic reflex threshold. For certain conditions there was an abrupt upward frequency shift at stimulus onset. For a fixed level the effect was frequency selective; the maximum frequency shift was obtained with tones approximately 1 2 octave below the SOAE. SOAE amplitude usually decreased but in some cases increased or remained unchanged. When amplitude changes were observed, the maximum shifts were observed for tones at or near the SOAE frequency. Changes in SOAEs were not observed for stimulus levels below 60 dB SPL. The effect is believed to be mediated by medial efferent neurons of the uncrossed olivocochlear bundle which arise in the medial region of the superior olivary complex and terminate on outer hair cells (OHCs). These results support those models which attribute SOAE generation to OHCs, and are indicative of an efferent influence on cochlear mechanics. A simple model is presented that proposes that efferent activity alters the tuning of the emission generator by causing changes in OHC membrane conductance.

It has been suggested that external noise maskers, like sensorineural hearing loss, have a linearizing effect on cochlear function and that external noise maskers can be used to simulate sensorineural hearing loss. To test these hypotheses, cubic‐difference‐tone (CDT) behavior was measured in normal hearing listeners using a forward‐masking paradigm for sinusoidal primaries presented in quiet and in the presence of low‐pass, high‐pass, and broadband noise. The noise was presented only during the primaries and could be considered as an additional forward masker. None of the noises used affected CDT behavior in a way that would support the hypothesis that noise has a linearizing effect on cochlear function. The range over which cubic difference tones could be measured was shifted by the amount that the thresholds for the primaries were shifted, but otherwise CDT behavior was similar to that observed in quiet. In contrast with results reported for persons with high‐frequency sensorineural hearing loss, high‐...

Auditory brain stem responses (ABR) and otoacoustic emissions (OAE) were measured in normal‐hearing subjects, using tone‐borst stimuli. The measured latency of wave V can be characterized as the sum of two components: (1) a “mechanical” component which varies with both intensity and frequency; and (2) a “neural” component which is independent of intensity and frequency. The mechanical component can be viewed as the time it takes for the stimulus to reach its point of maximum displacement on the basilar membrane. The neural component can be thought of as the time between this mechanical event and the generation of wave V. The determinants of OAE latencies are not completely understood. Current theories suggest that OAE's are determined by cochlear mechanical properties and that their latencies should be twice the “forward” travel time to the cochlear place which responds best to a given frequency component. Using similar stimuli, the latency of the “mechanical” component of the ABR was compared to the latency of the OAE. The data are consistent with the “two‐way” travel hypothesis. [Work supported by NINCDS.]