Hearing Thresholds, Minimum Response Levels, and Cross-Check Measures in Pediatric Audiology

Ear and hearing outcomes in Aboriginal infants living in an urban Australian area: the Djaalinj Waakinj birth cohort study

OBJECTIVE

Describe the ear and hearing outcomes in Aboriginal infants in an Australian urban area.

DESIGN

Aboriginal infants enrolled in the Djaalinj Waakinj prospective cohort study had ear health screenings at ages 2-4, 6-8 and 12-18 months and audiological assessment at ∼12 months of age. Sociodemographic, environmental characteristics, otoscopy, otoacoustic emissions, tympanometry and visual reinforcement audiometry data were collected.

STUDY SAMPLE

125 infants were enrolled in the study; 67 completed audiological assessment, 62, 54, and 58 of whom attended ear screenings at 2-4, 6-8 and 12-18 months.

RESULTS

Of the children that attended the audiological assessment, 36.5%, 50% and 64.3% of infants had otitis media (OM) at 2-4, 6-8 and 12-18 months. Using a 10 dB correction factor, 44.8% of infants had hearing loss (HL) (≥ 25 dB HL) at ∼ 12 months of age. More males (X2=5.4 (1df, p = 0.02)) and infants with OM at audiological assessment (X2=5.8 (1df, p = 0.02)) had HL. More infants that used a pacifier at 12-18 months of age had HL (X2=4.7 (1df, p = 0.03)).

CONCLUSION

Aboriginal infants in an urban area have high rates of HL and OM, which requires early surveillance and timely treatment to reduce the medical and developmental impacts of OM and HL.

Mismatch negativity as a marker of music perception in individual cochlear implant users: A spike density component analysis study

OBJECTIVE

Ninety percent of cochlear implant (CI) users are interested in improving their music perception. However, only few objective behavioral and neurophysiological tests have been developed for tracing the development of music discrimination skills in CI users. In this study, we aimed to obtain an accurate individual mismatch negativity (MMN) marker that could predict behavioral auditory discrimination thresholds.

METHODS

We measured the individual MMN response to four magnitudes of deviations in four different musical features (intensity, pitch, timbre, and rhythm) in a rare sample of experienced CI users and a control sample of normally hearing participants. We applied a recently developed spike density component analysis (SCA), which can suppress confounding alpha waves, and contrasted it with previously proposed methods.

RESULTS

Statistically detected individual MMN predicted attentive sound discrimination ability with high accuracy: for CI users 89.2% (278/312 cases) and for controls 90.5% (384/424 cases). As expected, MMN was detected for fewer CI users when the sound deviants were of smaller magnitude.

CONCLUSIONS

The findings support the use of MMN responses in individual CI users as a diagnostic tool for testing music perception.

SIGNIFICANCE

For CI users, the new SCA method provided more accurate and replicable diagnostic detections than preceding state-of-the-art.

Behavioral Audiology Procedures in Children With Down Syndrome

Purpose Normative data regarding behavioral audiologic testing procedures are based upon the general population and often do not apply to children with Down syndrome (DS). Testing children with DS can be challenging, and outcomes may be unreliable due to their different cognitive demands and delays. The aim of this study was to assess optimal audiologic testing procedures for specific age groups of children with DS. Method This study used a retrospective investigation of 273 children with DS (145 boys, 128 girls; average age at evaluation = 5.92 ± 4.74 years) who received an audiologic evaluation during 2013 as part of their medical care at a large pediatric hospital (satellite facilities included). Results Age ranges for the completion of audiometry procedures in children with DS are provided. Average age to reliably complete behavioral testing in children with DS was delayed by up to 30 months compared to typically developing children. The majority of children with DS achieved at least good-to-fair reliability for audiologic results starting at 16 months (85.7%) and two ear results at 6-10 years (76.1%). Though not statistically significant, the use of a two-tester assistant compared to a single tester appeared to be helpful in obtaining reliable results. Conclusion The results provide a guide to optimal audiologic test procedures for children with DS, as the standard audiologic guidelines for typically developing infants and children do not apply.

Audiological evaluation of infants using mother's voice

OBJECTIVES

Hearing loss is a serious problem in infants and children because it may interfere with the development of typical speech, verbal language, and auditory and communication skills. By measuring hearing ability (thresholds) as early as possible, even as early as during infancy, effective treatment can be administered. These treatments may significantly reduce the handicap associated with hearing loss. However, at times during behavioral auditory tests, observers cannot determine whether or not an accurate threshold was obtained. To support the use of infant audiometry for accurate diagnosis, audiologic behavioral responses may be obtained by selecting stimuli that interest infants, e.g., their mothers' voices.

METHODS

We evaluated 30 infants who were presented to our hospital for behavioral auditory assessment in 2016. The infants' ages ranged from 4 months to 3 years and 6 months. The mean age was 1 year and 10 months ±10 months (±standard deviation). The infants' hearing thresholds for their mothers' voices and warble tones at 250-4000 Hz were measured. Auditory brainstem response (ABR) had already been evaluated in 24 infants. Relationships between mother's voice and warble tone or ABR thresholds as well as responses to the initial stimuli and stimuli at the threshold were investigated. These responses were classified into four grades (no response, uncertain response, possible positive response, and positive response), and the response to mother's voice and warble tone were subsequently compared.

RESULTS

Mother's voice thresholds significantly correlated with all warble tone thresholds. In the relationship between the mother's voice threshold and average hearing levels of 500, 1000, and 2000 Hz, two infants were outliers. In these infants, the average hearing levels were relatively higher than the mother's voice thresholds. Judging from their ABR thresholds, the mother's voice thresholds were valid and the average hearing levels were worse than their original assessed hearing ability. The responses to mothers' voices were more distinct than those to warble tones, both for initial stimuli presentation and the determined threshold.

CONCLUSIONS

Audiologic behavioral responses to mothers' voices were clearer than those for warble tones. Evaluations that use the mother's voice threshold are useful for estimating hearing levels in infants.

Cochlear implantation outcomes in children with common cavity deformity; a retrospective study

Objective

A common cavity deformity (CCD) is a deformed inner ear in which the cochlea and vestibule are confluent forming a common rudimentary cystic cavity that results in profound hearing loss. There are few studies paying attention to common cavity. Our group is engrossed in observing the improvement of auditory and verbal abilities in children who have received cochlear implantation (CI), and comparing these targets between children with common cavity and normal inner ear structure.

Material and methods

A retrospective study was conducted in 12 patients with profound hearing loss that were divided into a common cavity group and a control group, six in each group matched in sex, age and time of implantation, based on inner ear structure. Categories of Auditory Performance (CAP) and speech intelligibility rating (SIR) scores and aided hearing thresholds were collected and compared between the two groups. All patients wore CI for more than 1 year at the Cochlear Center of Anhui Medical University from 2011 to 2015.

Results

Postoperative CAP and SIR scores were higher than before operation in both groups (p < 0.05), although the scores were lower in the CCD group than in the control group (p < 0.05). The aided threshold was also lower in the control group than in the CCD group (p < 0.05).

Conclusion

Even though audiological improvement in children with CCD was not as good as in those without CCD, CI provides benefits in auditory perception and communication skills in these children.