Crosscheck Principle in Pediatric Audiology Today: A 40-Year Perspective

Audiogram Estimation by Auditory Brainstem Response with NB CE-Chirp LS stimulus in Normal Hearing Infants

Introduction  NB CE-Chirp LS was developed to improve the audiogram estimation by auditory brainstem response (ABR) thresholds during audiological assessment of infants and difficult to test children. However, before we know how the stimulus behaves in several types of hearing loss, it is important we know how the stimulus behaves in normal hearing infants. Objective  To describe ABR thresholds with NB CE-Chirp LS stimulus for 500, 1,000, 2,000, and 4,000 Hz, as well as the amplitude and absolute latency for ABR thresholds. Methods  Auditory brainstem response thresholds were evaluated with the Eclipse EP25 system. NB CE-Chirp LS was presented using an ER-3A insert earphone. EEG filter was 30 Hz high-pass and 1,500 Hz low-pass. The ABR threshold was defined as the lowest intensity capable of clearly evoke wave V, accompanied by an absent response 5 dB below. Results  Eighteen normal hearing infants were evaluated. The mean and standard deviation (SD) of the ABR threshold (dB nHL) were: 23.8 (±4.2); 14.4 (±5.7); 6.0 (±5.0); and 7.0 (±5.9). The mean and SD of the absolute latency (ms) were: 8.86 (±1.12); 9.21 (±0.95); 9.44 (±0.78); and 9.64 (±0.52). The mean amplitude (nV) and SD were: 0.123 (±0.035); 0.127 (±0.039); 0.141 (±0.052); and 0.105 (±0.028), respectively, for 500, 1,000, 2,000 and 4,000 Hz. Conclusion  Auditory brainstem response threshold with NB CE-Chirp LS reaches low levels, in special for high frequencies. It provides absolute latencies similar between frequencies with robust amplitude. The results obtained brings to the examiner more confidence in the results registered.

Preserved Auditory Steady State Response and Envelope-Following Response in Severe Brainstem Dysfunction Highlight the Need for Cross-Checking

OBJECTIVES

Commercially available auditory steady state response (ASSR) systems are widely used to obtain hearing thresholds in the pediatric population objectively. Children are often examined during natural or induced sleep so that the recorded ASSRs are of subcortical origin, the inferior colliculus being often designated as the main ASSR contributor in these conditions. This report presents data from a battery of auditory neurophysiological objective tests obtained in 3 cases of severe brainstem dysfunction in sleeping children. In addition to ASSRs, envelope-following response (EFR) recordings designed to distinguish peripheral (cochlear nerve) from central (brainstem) were recorded to document the effect of brainstem dysfunction on the two types of phase-locked responses.

DESIGN

Results obtained in the 3 children with severe brainstem dysfunctions were compared with those of age-matched controls. The cases were identified as posterior fossa tumor, undiagnosed (UD), and Pelizaeus-Merzbacher-Like Disease. The standard audiological objective tests comprised tympanograms, distortion product otoacoustic emissions, click-evoked auditory brainstem responses (ABRs), and ASSRs. EFRs were recorded using horizontal (EFR-H) and vertical (EFR-V) channels and a stimulus phase rotation technique allowing isolation of the EFR waveforms in the time domain to obtain direct latency measurements.

RESULTS

The brainstem dysfunctions of the 3 children were revealed as abnormal (weak, absent, or delayed) ABRs central waves with a normal wave I. In addition, they all presented a summating and cochlear microphonic potential in their ABRs, coupled with a normal wave I, which implies normal cochlear and cochlear nerve function. EFR-H and EFR-V waveforms were identified in the two cases in whom they were recorded. The EFR-Hs onset latencies, response durations, and phase-locking values did not differ from their respective age-matched control values, indicating normal cochlear nerve EFRs. In contrast, the EFR-V phase-locking value and onset latency varied from their control values. Both patients had abnormal but identifiable and significantly phase-locked brainstem EFRs, even in a case with severely distorted ABR central waves. ASSR objective audiograms were recorded in two cases. They showed normal or slightly elevated (explained by a slight transmission loss) thresholds that do not yield any clue about their brainstem dysfunction, revealing the method's lack of sensitivity to severe brainstem dysfunction.

CONCLUSIONS

The present study, performed on 3 sleeping children with severe brainstem dysfunction but normal cochlear responses (cochlear microphonic potential, summating potential, and ABR wave I), revealed the differential sensitivity of three auditory electrophysiological techniques. Estimated thresholds obtained by standard ASSR recordings (cases UD and Pelizaeus-Merzbacher-Like Disease) provided no clue to the brainstem dysfunction clearly revealed by the click-evoked ABR. EFR recordings (cases posterior fossa tumor and UD) showed preserved central responses with abnormal latencies and low phase-locking values, whereas the peripheral EFR attributed to the cochlear nerve was normal. The one case (UD) for which the three techniques could be performed confirms this sensitivity gradient, emphasizing the need for applying the Cross-Check Principle by avoiding resorting to ASSR recording alone. The entirely normal EFR-H recordings observed in two cases further strengthen the hypothesis of its cochlear nerve origin in sleeping children.

A Survey of U.S. Audiologists' Usage of and Attitudes Toward Otoacoustic Emissions

PURPOSE

Otoacoustic emissions (OAEs) provide information on outer hair cell function and have multiple clinical applications. Two types of OAEs, transient-evoked OAEs (TEOAEs) and distortion product OAEs (DPOAEs), are currently utilized in clinical practice. However, it remains unknown how confident U.S. clinicians are in performing and interpreting TEOAEs and DPOAEs. Additionally, the extent to which U.S. audiologists incorporate OAEs for different clinical applications and populations has not been thoroughly investigated. To fill these gaps in knowledge, this study characterized the attitudes toward and usage of TEOAEs and DPOAEs in a sample of U.S. audiologists.

METHOD

This study utilized an online survey distributed to U.S. audiologists through multiple channels from January to March 2021. A total of 214 completed surveys were included in the analysis. Results were analyzed descriptively. Associations between variables and comparisons between users of DPOAEs only and users of TEOAEs and DPOAEs were also examined.

RESULTS

DPOAEs were reportedly utilized more frequently and with greater confidence than TEOAEs. The most common clinical application of both OAE types was a cross-check. Significant associations were found between responses to DPOAE questions and the clinician's setting and patient age. There were some significant differences between users of DPOAEs only and users of TEOAEs and DPOAEs.

CONCLUSIONS

Results suggest that U.S. audiologists utilize OAEs for multiple clinical purposes and that there are appreciable differences in terms of attitudes toward and usage of DPOAEs versus TEOAEs. Future work could investigate the reasons that underlie these differences to further improve clinical implementation of OAEs.

Task force Guideline of Brazilian Society of Otology ‒ hearing loss in children - Part I ‒ Evaluation

OBJECTIVES

To provide an overview of the main evidence-based recommendations for the diagnosis of hearing loss in children and adolescents aged 0 to 18 years.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on childhood hearing loss were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The evaluation and diagnosis of hearing loss: universal newborn hearing screening, laboratory testing, congenital infections (especially cytomegalovirus), genetic testing and main syndromes, radiologic imaging studies, vestibular assessment of children with hearing loss, auditory neuropathy spectrum disorder, autism spectrum disorder, and noise-induced hearing loss.

CONCLUSIONS

Every child with suspected hearing loss has the right to diagnosis and appropriate treatment if necessary. This task force considers 5 essential rights: (1) Otolaryngologist consultation; (2) Speech assessment and therapy; (3) Diagnostic tests; (4) Treatment; (5) Ophthalmologist consultation.

Reflux symptoms and vocal characteristics in adults with non-organic voice disorders

BACKGROUND

 Laryngopharyngeal reflux (LPR) is prevalent and can lead to voice disorders, but its diagnosis is difficult, because of limited correlations between clinical symptoms and organic pathology. Various tools and methods have been explored to aid a diagnosis of LPR.

OBJECTIVE

 To investigate associations between reflux symptoms, acoustic-, perceptual-, and physical vocal characteristics, glottal function index (GFI), and vocal handicap index (VHI) in adults with non-organic voice disorders.

METHODS

 Data of 51 adults with non-organic voice disorders were collected, using a retrospective cohort explorative research design, at a private ear, nose and throat specialist practice in Gauteng, South Africa. Quantitative outcomes were compared between reflux symptom index (RSI), acoustic characteristics (jitter, shimmer and fundamental frequency [F0]), maximum phonation time, perceptual- (GRBASI) and physical vocal characteristics, GFI and VHI.

RESULTS

 The RSI showed positive fair correlations against GFI, VHIP and caffeine intake, indicating an increase in reflux symptoms with higher scores on the various measures. Moderate correlations were also found between GFI and VHIP, grade of hoarseness and jitter, strain and VHIP, strain and VHI total (VHIT) and between Asthenia and jitter. Very strong correlations were found within the various subsections of the VHI as well as between jitter and shimmer and between F0-male and physical symptoms of the VHI (VHIP).

CONCLUSION

 Results indicated associations between reflux symptoms, vocal characteristics, the GFI and the VHI. Based on the correlations found these tools used in conjunction could improve clinical diagnosis of LPR. Implications of these findings are promising, but further research is recommended.Contribution: This study contributes to the body of knowledge to support the accurate clinical diagnosis of LPR using subjective measures to determine LPR symptoms, as well as acoustic analysis.

Evaluation of Remote Check: A Clinical Tool for Asynchronous Monitoring and Triage of Cochlear Implant Recipients

BACKGROUND

A new Remote Check App permits remote self-testing of hearing function for Nucleus cochlear implant (CI) recipients and enables asynchronous review by their clinician to support patient-management decisions.

OBJECTIVES

To evaluate the Remote Check App for: (1) ease of use; (2) overall acceptance of the test battery by CI recipient or their carer in the home setting; (3) test-retest reliability of audiological threshold and speech recognition measures via wireless streaming; and (4) to compare outcomes from patient-driven measures with conventional clinician-driven measurements of aided-hearing function.

DESIGN

Single-site, prospective, repeated-measures cohort study with 32 experienced CI users (28 adults and 4 children).

METHODS

Participants completed self-testing using the Remote Check app at home and in the clinic. Measures include audiological, objective and subjective tests. Self-administered speech recognition in noise, via the digit triplets test (DTT) and aided thresholds, via the aided threshold test (ATT) were reassessed in free-field and by clinicians following conventional clinical protocols. Results of ATT and DTT were compared across test conditions. Completion time and perceived ease of self-driven assessments were documented. Insights from subsequent real-world experience with Remote Check are summarized and compared to the study findings.

RESULTS

Remote Check was rated as easy to use by the majority (87%) of subjects. Mean group test-retest score differences for self-administered testing within the clinic versus at-home environments were nonsignificant (p > 0.05): 1.4 dB (SD = 1.97) for ATT and 1.6 dB (SD = 1.54) for DTT. Mean group test-retest score difference for patient-driven DTT in streamed versus the free-field condition was 1.8 dB (SD = 2.02). Self-administered, streamed, ATT via Remote Check, resulted in significantly lower thresholds compared to clinician-driven warble-tone thresholds in the free-field by 6.7 dB (SD = 6.8) (p < 0.001). ATT thresholds via Remote Check were not significantly different from predicted thresholds based on the Threshold Sound Pressure Level of the sound processor.

CONCLUSION

Remote Check is the first CI telehealth assessment tool that uses wireless streaming to enable comprehensive, easy and reliable self-testing of hearing function by the CI recipient or their carer, in the comfort of their home. Asynchronous access to test results can assist clinicians in monitoring and triaging individuals for appropriate patient-management based on their needs. Use of remote monitoring may also help to reduce the burden of unnecessary clinic visits on clinic resources, patient travel time and associated costs. Remote Check is an important step toward addressing the current growing need for asynchronous audiological telepractice to support long-term care of CI recipients.

The Correlation Between Click-Evoked Auditory Brainstem Responses and Future Behavioral Thresholds Determined Using Universal Newborn Hearing Screening

This retrospective study was undertaken to assess the correlation between click-evoked auditory brainstem responses and behavioral hearing tests. We recruited a total of 16646 infants born in Ditmanson Medical Foundation Chia-Yi Christian Hospital, Taiwan, from 2012 to 2018 for such assessment purpose. Their data including the click-evoked auditory brainstem response (ABR), referral, and diagnostic follow-up were collected. Spearman correlation method was employed to assess the relationship between ABR and pure-tone threshold. The correlation between the click-evoked ABR that met the National Health Administration standards and the click-evoked ABR derived from estimates before and after the 2.5 years of age effectively predicted the toddlers' pure-tone audiometry (PTA) thresholds at 2-4 kHz.

Knowledge and Awareness of Ear Protection Devices for Sound Sensitivity by Individuals With Autism Spectrum Disorders

Purpose Sensitivity to sounds and atypical reactions to sensory input by individuals with autism spectrum disorder (ASD) have been reported in the literature. In response to this sensitivity, some individuals use ear protection devices (EPDs) such as noise-canceling headphones, earplugs, or earmuffs to attenuate the perceived unpleasant sounds. Given the communication deficits often noted in this population and the essential role of hearing in speech and language development, the impact of wearing EPDs to attenuate sound needs to be explored. The purpose of this study was to obtain information from various stakeholders regarding their opinions about use of EPDs in individuals with ASD and perceived benefits and possible concerns of EPD use. Method A survey was constructed to assess the opinions of speech-language pathologists, audiologists, teachers, and graduate students about EPDs among individuals with ASD. A total of 255 professionals and graduate students completed the survey. Results The vast majority of respondents indicated a level of awareness of EPDs within this population. Regarding observed use of such devices, the majority of participants (66%) reported observing individuals with ASD using EPDs. The most commonly used devices observed were headphones (91%), followed by earmuffs (44%) and earplugs (33%). Respondents who had experience recommending and/or using EPDs with individuals with ASD were asked to report on major reasons why the devices were used and the perceived benefits and possible negative effects. Conclusions There appears to be uncertainty among various stakeholders of the benefits and possible negative effects of EPD use by individuals with ASD. Additionally, there is a dearth of research in this area, and the necessity for specific guidelines for recommending and monitoring EPD use is indicated.

Acquired Central Auditory Processing Disorder in Service Members and Veterans

Purpose A growing body of evidence suggests that military service members and military veterans are at risk for deficits in central auditory processing. Risk factors include exposure to blast, neurotrauma, hazardous noise, and ototoxicants. We overview these risk factors and comorbidities, address implications for clinical assessment and care of central auditory processing deficits in service members and veterans, and specify knowledge gaps that warrant research. Method We reviewed the literature to identify studies of risk factors, assessment, and care of central auditory processing deficits in service members and veterans. We also assessed the current state of the science for knowledge gaps that warrant additional study. This literature review describes key findings relating to military risk factors and clinical considerations for the assessment and care of those exposed. Conclusions Central auditory processing deficits are associated with exposure to known military risk factors. Research is needed to characterize mechanisms, sources of variance, and differential diagnosis in this population. Existing best practices do not explicitly consider confounds faced by military personnel. Assessment and rehabilitation strategies that account for these challenges are needed. Finally, investment is critical to ensure that Veterans Affairs and Department of Defense clinical staff are informed, trained, and equipped to implement effective patient care.

Hearing loss prevalence and hearing health among school-aged children in the Canadian Arctic

OBJECTIVE

Hearing loss is an important health concern in Canada's Arctic. The objective of this research was to provide information on the prevalence of childhood hearing loss in Nunavut.

DESIGN

This cross-sectional study involved comprehensive audiologic assessments of school-aged children in six communities to determine overall and community-specific prevalence of hearing loss. Data were collected about hearing aid use and factors affecting use through a parent questionnaire.

STUDY SAMPLE

Assessments were completed for 644 children in kindergarten to grade 6.

RESULTS

124 (19.3%) children had hearing loss of ≥ 30 dB HL at one or more frequencies in at least one ear (93.5% conductive loss). Applying a Canadian prevalence study definition, 148 (23.5%) children had hearing loss. Tympanic membrane perforations were present in 36.8% (n = 28) of children with unilateral and 45.8% (n = 22) with bilateral loss.

CONCLUSIONS

The prevalence of hearing loss in Canada's North was almost three times that reported for non-indigenous children. One in five school-aged children was found to have hearing loss that is likely to affect classroom learning and social/emotional development. A hearing health strategy tailored to this population is critically needed.

Patient Safety in Audiology

There is a need to educate audiologists, physicians, and other clinicians about patient safety in audiology. This article addresses the many aspects of patient safety and the applicability to the practice of audiology in health care. Clinical examples of strategies to build a culture of patient safety are provided.

Exposures to fine particulate matter (PM2.5) and ozone above USA standards are associated with auditory brainstem dysmorphology and abnormal auditory brainstem evoked potentials in healthy young dogs

BACKGROUND

Delayed central conduction times in the auditory brainstem have been observed in Mexico City (MC) healthy children exposed to fine particulate matter (PM_2.5) and ozone (O₃) above the current United States Environmental Protection Agency (US-EPA) standards. MC children have α synuclein brainstem accumulation and medial superior olivary complex (MSO) dysmorphology. The present study used a dog model to investigate the potential effects of air pollution on the function and morphology of the auditory brainstem.

METHODOLOGY

Twenty-four dogs living in clean air v MC, average age 37.1 ± 26.3 months, underwent brainstem auditory evoked potential (BAEP) measurements. Eight dogs (4 MC, 4 Controls) were analysed for auditory brainstem morphology and histopathology.

RESULTS

MC dogs showed ventral cochlear nuclei hypotrophy and MSO dysmorphology with a significant decrease in cell body size, decreased neuronal packing density with regions in the nucleus devoid of neurons and marked gliosis. MC dogs showed significant delayed BAEP absolute wave I, III and V latencies compared to controls.

CONCLUSIONS

MC dogs show auditory nuclei dysmorphology and BAEPs consistent with an alteration of the generator sites of the auditory brainstem response waveform. This study puts forward the usefulness of BAEPs to study auditory brainstem neurodegenerative changes associated with air pollution in dogs. Recognition of the role of non-invasive BAEPs in urban dogs is warranted to elucidate novel neurodegenerative pathways link to air pollution and a promising early diagnostic strategy for Alzheimer's Disease.

Management of non-organic hearing loss in children - A case study

A 10 year-old girl was admitted due to the claim of progressively developing hearing loss. The impedance audiometry showed no abnormalities but it was impossible to obtain reliable outcomes during pure tone audiometry assessment. The girl was additionally sent for speech audiometry, indicating a bilateral hearing loss and objective evaluations such as distortion product otoacoustic emissions and auditory brainstem responses, which results indicated a normal hearing. On the second day, repeated subjective audiometric tests showed also normal hearing, despite constantly reported hearing loss. After the psychological consultation and exclusion of neurologic pathology, the diagnosis of non-organic hearing loss was stated and the girl was scheduled for regular appointments with psychologist.