Distortion Product Otoacoustic Emission Screening Research Articles

Effects of ambient air pollution, fresh fruit and vegetable intakes as well as maternal psychosocial stress on the outcome of newborn otoacoustic emission hearing screening

BackgroundNewborn hearing screening results indicated that more than 40% of the detected infants had no recognized risk factors. To determine whether maternal exposure to ambient air pollutants and experience of stressful life event, as well as lack of fresh fruit and vegetable during pregnancy are associated with the abnormal hearing development among newborns.MethodsA total of 1193 newborns and their mothers were recruited in this study. Personal information and covariates were collected by face to face interview. Medical examination results of newborns and their mothers were extracted from medical record. We estimated personal air pollutant exposure level through inverse distance weighted method based on data from air quality monitoring stations and assessed the auditory development of newborns via distortion product otoacoustic emission (DPOAE). Unconditional logistic regression model was used to estimate the relationship between DPOAE screening result and the potential influential factors as well as the combined effect.ResultsThe results indicated that PM10 exposure during the second trimester and stressful life event during the third trimester could increase the risk of not passing DPOAE test among newborns. However, frequent intakes of fruit and vegetable significantly reduced the risk. There was a synergetic interaction between PM10 exposure and stressful life event on neonatal hearing development.ConclusionsTo alleviate abnormal auditory development among fetus, pregnant woman should decrease the exposures to ambient air pollutant and negative life event and at the same time, intake sufficient fresh fruit and vegetable.

Feasibility of a hearing screening programme using DPOAEs in 3-year-old children in South Auckland

ObjectivesIn New Zealand (NZ), permanent hearing loss is associated with higher levels of socioeconomic deprivation, and is more prevalent amongst Māori and Pacific than NZ European children. Many of these hearing losses are detected through newborn hearing screening, however there is a need to screen children again later, to look for childhood hearing losses that are either late-onset, progressive, or acquired. This study evaluated the feasibility of implementing an objective screening protocol that includes otoscopy, distortion product otoacoustic emission screening (DPOAEs), and tympanometry. It also evaluated the feasibility of using Early Learning Centres (ELCs) to contact families, recruit, and test 3-year-old children from an area of high socioeconomic deprivation in Auckland, New Zealand. MethodsSixty-one 3-year-old children were recruited from ELCs within the Counties Manukau District Health Board (CMDHB) region which services the geographical area of South Auckland. The first part of the screening protocol consisted of otoscopy, DPOAEs, and tympanometry. Children identified with hearing loss and/or middle ear problems were either referred directly to Otolaryngology/Audiology at the local hospital or invited back for a re-screen 4–8 weeks later. Children who were referred from the screening were followed up to track and document their subsequent clinical pathway through the public health system. ResultsMean overall time for the screening protocol was 4.1 minutes. The combination of otoscopy, DPOAEs, and tympanometry was well accepted by the 3-year-old children. DPOAE amplitude and signal-to-noise ratio results significantly differentiated between different tympanometry results, providing support for this combination of measures to accurately screen for hearing loss and/or middle ear disease. Thirty-eight of the 61 children (62%) passed the screening protocol. Of the remaining 23 children, five were referred to the hospital after not passing the screening, but following more in-depth audiological testing, were discharged with normal hearing. Six children referred to the hospital were diagnosed with varying degrees of conductive hearing loss, and two of the six received grommet insertion surgery. The remaining 12 children who were referred to the hospital were lost to follow-up, highlighting challenges for the families to successfully navigate the current public health system. ConclusionThis study demonstrates that identifying hearing loss and ear disease in 3-year-old children in the pre-school setting is feasible. A number of barriers were identified in the current health system that contribute to a large proportion of children referred with suspected hearing loss and ear disease being unsuccessful in accessing Otolaryngology/Audiology clinical care through the local hospital.

‘Asymptomatic’ South Auckland preschool children have significant hearing loss and middle ear disease

BackgroundSeven hundred children were recalled for hearing screening at age 2–3 years due to a problem with their newborn hearing screen. They had all been well babies with no identified risk factors for hearing loss and hence were not scheduled for targeted follow-up to retest hearing. MethodsThere were 485 children (69%) that attended the recall. The average age was 36 months (SD 3.7). Family ethnicity was Pacific Island (36%), Asian (26%), NZ European (13%), and Māori (11%), and there was a high level of deprivation in the study population. Children were screened using distortion product otoacoustic emission (DPOAE) and a parent or caregiver completed a 14-item questionnaire about ear health. The children that did not pass screening were given appointments for audiology testing. Children with hearing loss and/or middle ear problems were referred for otolaryngology review and further hearing assessments. ResultsAbout one third (36%; n = 176) of children did not pass DPOAE screening; 82 (17%) had abnormal type B tympanograms and hearing loss; 29 underwent insertion of ventilation tubes, and one had a perforated tympanic membrane. There was a significant association between failed tympanometry and hearing loss (Chi-squared = 16.67, p < .001).Five children had permanent sensorineural hearing loss (SNHL), two of whom required cochlear implants for idiopathic hearing loss, with no specific risk factors. Overall 380 of 485 children screened were deemed to have normal hearing (i.e. 22% failed hearing). From the questionnaire, 15% of the caregivers with no suspicion of hearing problems did have children with significant hearing loss. Regression analysis showed that Pacific/Māori ethnicity was significantly associated with risk of hearing loss, together with questionnaire items identifying hearing problems and breathing problems. ConclusionsThere is a high proportion of children in South Auckland with unsuspected hearing loss; a different approach to hearing screening is warranted for this population with high rates of middle ear disease at age 3.

Pressurized Wideband Absorbance Findings in Healthy Neonates: A Preliminary Study.

The present study aimed to establish normative data for wideband absorbance (WBA) measured at tympanometric peak pressure (TPP) and 0 daPa and to assess the test-retest reliability of both measurements in healthy neonates. Participants of this cross-sectional study included 99 full-term neonates (165 ears) with mean chronological age of 46.7 hrs (SD = 26.3 hrs). Of the 99 neonates, 58 were Malay, 28 were Indian, and 13 were Chinese. The neonates who passed high-frequency (1 kHz) tympanometry, acoustic stapedial reflex, and distortion product otoacoustic emission screening tests were assessed using a pressurized WBA test (wideband tympanometry). To reduce the number of measurement points, the WBA responses were averaged to 16 one-third octave frequency bands from 0.25 to 8 kHz. A mixed-model analysis of variance was applied to the data to investigate the effects of frequency, ear, gender, and ethnicity on WBA. The analysis of variance was also used to compare between WBA measured at TPP and 0 daPa. An interclass correlation coefficient test was applied at each of the 16 frequency bands to measure the test-retest reliability of WBA at TPP and 0 daPa. Both WBA measurements at TPP and 0 daPa exhibited a multipeaked pattern with 2 maxima at 1.25-1.6 kHz and 6.3 kHz and 2 minima at 0.5 and 4 kHz. The mean WBA measured at TPP was significantly higher than that measured at 0 daPa at 0.25, 0.4, 0.5, 1.25, and 1.6 kHz only. A normative data set was developed for absorbance at TPP and at 0 daPa. There was no significant effect of ethnicity, gender, and ear on both measurements of WBA. The test-retest reliability of WBA at TPP and 0 daPa was high with the interclass correlation coefficient ranging from 0.77 to 0.97 across the frequencies. Normative data of WBA measured at TPP and 0 daPa for neonates were provided in the present study. Although WBA at TPP was slightly higher than the WBA measured at 0 daPa at some frequencies below 2 kHz, the WBA patterns of the 2 measurements were nearly identical. Moreover, the test-retest reliability of both WBA measurements was high.

Reflectance Measures from Infant Ears With Normal Hearing and Transient Conductive Hearing Loss.

The objective is to develop methods to utilize newborn reflectance measures for the identification of middle-ear transient conditions (e.g., middle-ear fluid) during the newborn period and ultimately during the first few months of life. Transient middle-ear conditions are a suspected source of failure to pass a newborn hearing screening. The ability to identify a conductive loss during the screening procedure could enable the referred ear to be either (1) cleared of a middle-ear condition and recommended for more extensive hearing assessment as soon as possible, or (2) suspected of a transient middle-ear condition, and if desired, be rescreened before more extensive hearing assessment. Reflectance measurements are reported from full-term, healthy, newborn babies in which one ear referred and one ear passed an initial auditory brainstem response newborn hearing screening and a subsequent distortion product otoacoustic emission screening on the same day. These same subjects returned for a detailed follow-up evaluation at age 1 month (range 14 to 35 days). In total, measurements were made on 30 subjects who had a unilateral refer near birth (during their first 2 days of life) and bilateral normal hearing at follow-up (about 1 month old). Three specific comparisons were made: (1) Association of ear's state with power reflectance near birth (referred versus passed ear), (2) Changes in power reflectance of normal ears between newborn and 1 month old (maturation effects), and (3) Association of ear's newborn state (referred versus passed) with ear's power reflectance at 1 month. In addition to these measurements, a set of preliminary data selection criteria were developed to ensure that analyzed data were not corrupted by acoustic leaks and other measurement problems. Within 2 days of birth, the power reflectance measured in newborn ears with transient middle-ear conditions (referred newborn hearing screening and passed hearing assessment at age 1 month) was significantly greater than power reflectance on newborn ears that passed the newborn hearing screening across all frequencies (500 to 6000 Hz). Changes in power reflectance in normal ears from newborn to 1 month appear in approximately the 2000 to 5000 Hz range but are not present at other frequencies. The power reflectance at age 1 month does not depend significantly on the ear's state near birth (refer or pass hearing screening) for frequencies above 700 Hz; there might be small differences at lower frequencies. Power reflectance measurements are significantly different for ears that pass newborn hearing screening and ears that refer with middle-ear transient conditions. At age 1 month, about 90% of ears that referred at birth passed an auditory brainstem response hearing evaluation; within these ears the power reflectance at 1 month did not differ between the ear that initially referred at birth and the ear that passed the hearing screening at birth for frequencies above 700 Hz. This study also proposes a preliminary set of criteria for determining when reflectance measures on young babies are corrupted by acoustic leaks, probes against the ear canal, or other measurement problems. Specifically proposed are "data selection criteria" that depend on the power reflectance, impedance magnitude, and impedance angle. Additional data collected in the future are needed to improve and test these proposed criteria.

Otoacoustic Emission Screening of Auditory Dysfunction of High Risk Infants at Tertiary Care Setting

Objective .Hearing deficit in newborns may go unnoticed leading to crucial handicap to language development and impaired socioacademic profiles.Early detection and intervention is of utmost importance as safeguard against the consequent healthcare burden. Method .Present study employed two stage distortion product otoacoustic emission(DPOAE) for assessment of hearing function in infants of high risk background refered by the obstetric and pediatric sections of medical college .Cases failing hearing function test by DPOAE at both stages were given Brain stem evocked response audiometry testing to confirm hearing loss. Results .Gestational diabetes and hypertension were the commonest risk factors for reference of babies for auditory function screening in the studied 50 cases.84% of the refered high hearing risk children passed the DPOAE test at very first stage. Further 14% cleared hearing test on repeat DPOAE testing,leaving just 1(2%) baby then sent for BERA testing and definitive diagnosis of hearing loss. Conclusion .The Distortion product oto acoustic emission,two stage screening strategy for auditory dysfunction in infants proved highly sensitive and reliablefor early detection and hence early intervention. The DPOAE screening is best suited for early detection and intervention programme in infant hearing loss deserving wide adoption.

The potential risk factors and the identification of hearing loss in infants.

To identify potential risk factors for hearing loss from the infant with high risk criteria as guided by the Joint Committee on Infant Hearing (JCIH, 2000). 490 infants with age range of 2days to 6months who had undergone detailed audiological evaluation during for the period of 3years at Gauhati Medical College Hospital were taken for the study. The hearing screening was performed on each infant using Distortion Product Otoacoustic Emission (DPOAE) testing. The infants who failed DPOAEs screening were followed up and Auditory Brainstem Response testing. Out of 490 high risk infants who had undergone detailed audiological evaluation 145 infants were found to be having hearing loss. Out of 145 infants 73 infants were male and 72 infants were female. The risk factor for hearing loss with the highest incidence was hyperbilirubenemia, Apgar scores of 0-4 at 1min or 0-6 at 5min was the second most prevalent risk factor, followed by TORCH infections. This study suggests the need for review of high risk register that is used along with the physiological and electrophysiological hearing test to screen the infants. The high risk register remains helpful in determining follow up plans so that children who may develop late onset of hearing loss will not be missed. Being aware of which risk factors are more likely to cause hearing loss in infants would be helpful to plan for follow up these children.

Infant hearing screening: effects of timeline

Universal infant hearing screening using otoacoustic emission and auditory brain-stem response audiometry is widely administered to attain the goals of early identification of, and intervention for hearing impairment. Concerns regarding screening specificity have, however, been raised. False positives may result from vernix occlusion in the ear canal or transient middle ear effusion, and can result in substantial costs to health care systems. The current study investigates the effects of age and time interval between tests on hearing assessment results. Three hundred and seventeen positive screens from a 2-stage distortion product otoacoustic emission (DPOAE) screening programme in Hong Kong, who subsequently received diagnostic auditory brainstem response (ABR) assessment and monitoring, were investigated. Differences in diagnostic ABR results were compared among infants of different ages at tests, and with different time lapses after DPOAE screening. The proportion of those having persistent hearing impairment, conductive loss and impairment of moderate degree or above, were also compared. A significantly higher rate of normal ABR thresholds (60%versus 24%) was noted in infants assessed after age 50 days, and in infants diagnostically assessed with a time lapse of over 20 days post-DPOAE screening (65%versus 42%). Delaying diagnostic ABR assessment may reveal a higher percentage of normal thresholds, and hence probably higher specificity. Time delay may allow for spontaneous resolution of transient outer and middle ear conditions. However, the goals of early identification and intervention, as well as possible parental anxiety with delayed assessment, should also be considered when reviewing infant hearing screening schedules.

Hearing Screening Outcomes in Infants of Pregestational Diabetic Mothers

Hearing screening results for newborns of diabetic mothers were compared with those of nondiabetic controls. This study was a retrospective chart review of mothers with pregestational diabetes mellitus and their neonates (n=73) who received newborn hearing screening between January 1, 2000, and May 1, 2002. A group of nondiabetic mothers and their infants (n=73), with birth dates that matched the diabetic group, served as controls. A 2-tiered hearing screening protocol, employing distortion product otoacoustic emission (DPOAE) and automated auditory brainstem response (A-ABR) screening techniques, was used. The DPOAE screening failure rate was 5.5% (4/73) for babies in the nondiabetic control group and 11.0% (8/73) for infants of diabetic mothers; this difference was not statistically significant. The A-ABR failure rate was 9.1% (1/11) for the diabetic group compared with 0% (0/4) for the controls, but the A-ABR was measured for only a small number of participants in each group. The frequency of premature birth and abnormal birth weight was significantly greater for the infants of diabetic mothers compared with controls. Given the greater frequency of prematurity and abnormal birth weight in the population of neonates born to diabetics, additional research using A-ABR is recommended.

Outcome of newborn hearing screening by ABR compared with four different DPOAE pass criteria.

The purpose of this study is to compare the effectiveness and utility of distortion product otoacoustic emission (DPOAE) and auditory brain stem response (ABR) testing as screening methodologies suitable for universal application at a large birthing hospital. Five hundred sixty-nine neonates (1184 ears) without risk indicators for hearing loss underwent DPOAE and ABR screening before hospital discharge at birth. All ears (100%) passed the ABR screening. DPOAE results were categorized on the basis of the number of frequencies at which emissions were obtained as well as presence versus absence of a replicated response at each test frequency. Pass and refer rates varied widely, on the basis of whether the presence of DPOAE response at 2000 Hz or replication were required. With the most stringent criteria, only 64.44% of ears passed, whereas with the least stringent criteria 88.94% passed. Given that 100% of ears passed according to the gold standard of the ABR screening, these results indicate false-positive rates ranging from 11% to 35% by DPOAE screening. This discrepancy in pass and refer rates when various criteria are applied indicates the need for standardization and further comparison of appropriate pass criteria for newborn hearing screening programs.