Otitis media sequelae and hearing in adolescence after administration of an 11-valent conjugate pneumococcal vaccine in infancy: a prospective cohort study with long-term follow-up of the ARIVAC trial.

BACKGROUND: Pneumococcal conjugate vaccines (PCVs) have been shown in randomised controlled trials and epidemiological studies to prevent acute otitis media caused by vaccine serotype pneumococci, although their role in preventing complications of acute otitis media is less clear. We hypothesised that the 11-valent PCV would reduce the long-term sequelae of acute otitis media, including moderate-to-severe ear disease and hearing loss. METHODS: This prospective cohort study, referred to as 11PCV study, included follow-up after 16-20 years of children previously enrolled in 2000-04, at age 6 weeks to 6 months, in the randomised, placebo-controlled, ARIVAC trial of 11-valent PCV for the prevention of radiographical pneumonia. The ARIVAC trial and this 11PCV study were conducted at six study centres in Bohol, Philippines. Ear disease was classified using video-otoscopy review and observations derived from the ear exam. The final classification of the worst ear disease was mild (ie, acute otitis media, otitis media with effusion, healed perforation, or tympanosclerosis), moderate (ie, dry perforation or adhesive otitis media), or severe (chronic suppurative otitis media). Hearing loss was assessed following a standard schema and classified according to the worst ear as mild (>15 to 30 dB puretone average) or moderate-to-profound (>30 dB pure tone average). We calculated the relative and absolute risk reduction in the primary outcome of moderate-to-severe ear disease and the secondary outcomes of mild or moderate-to-profound hearing loss in adolescents who previously received the 11-valent PCV compared with those who received placebo during infancy in ARIVAC. FINDINGS: Of the 15 593 children assessed for eligibility in ARIVAC, 12 194 were randomly assigned and 8926 were alive and could be located for enrolment in this 11PCV study between Sept 19, 2016, and Dec 13, 2019. 8321 (4188 in the vaccine group and 4133 in the placebo group) completed follow-up of the 11PCV study by March 30, 2020, and had sufficient data to classify ear disease and be included in the primary outcome analysis. The primary outcome of the absolute risk reduction in moderate-to-severe ear disease in the vaccine group (310 [7·4%] of 4188) versus those in the placebo group (356 [8·6%] of 4133) was 1·2% (95% CI 0·0-2·4; p=0·046) and the relative risk reduction was 14·1% (0·0 to 26·0). There were no differences in secondary outcomes of mild hearing loss or moderate-to-profound hearing loss between the vaccine and placebo groups. INTERPRETATION: The absolute risk reduction for moderate-to-severe ear disease in adolescence of 1·2% (12 per 1000 children) was almost three times higher than the 0·45% reduction (4·5 per 1000 children) in radiographical pneumonia in the first 2 years of life shown in ARIVAC. Administration of 11-valent PCV in infancy was associated with absolute and relative risk reductions in the sequelae of acute otitis media 16-20 years after the original ARIVAC trial. FUNDING: Bill & Melinda Gates Foundation.

Individuals with Tinnitus Report More Positive Experiences following Internet-Based Cognitive Behavioral Therapy.

BACKGROUND: This study aimed to examine whether individuals with chronic tinnitus report more positive experiences following internet-based cognitive behavioral therapy (CBT). METHODS: A mixed-methods design was used, nested in clinical trials evaluating internet interventions for tinnitus. Participants (n = 164) completed online questionnaires (both structured and open-ended) providing demographic information as well as health variables (e.g., tinnitus distress, anxiety, depression, insomnia). An open-ended question listing positive effects or outcomes related to having tinnitus was also included. Responses to the open-ended questions were analyzed using qualitative content analysis. RESULTS: Of the 164 eligible participants, 32.3% (n = 53) provided at least 1 positive experience both at pre- and post-intervention, with 9.1% (n = 19) providing positive experiences only at pre-intervention, 49 (29.9%) providing positive experiences only at post-intervention, and 28.7% (n = 47) of the participants did not provide any positive experiences on either measurement occasion. Significantly more positive experiences were reported following the intervention in the overall sample (p < 0.0001, paired sample t-test). In addition, participants who reported positive experiences in both pre- and post-intervention also reported more positive experiences following intervention (p = 0.008, paired sample t-test). CONCLUSIONS: Internet-based CBT can help individuals with tinnitus to think more positively by changing unhelpful thought patterns. Open-ended questions can supplement structured questionnaires to measure treatment outcomes.

Clinical Genetic Testing for Hearing Loss: Implications for Genetic Counseling and Gene-Based Therapies.

Genetic factors contribute significantly to congenital hearing loss, with non-syndromic cases being more prevalent and genetically heterogeneous. Currently, 150 genes have been associated with non-syndromic hearing loss, and their identification has improved our understanding of auditory physiology and potential therapeutic targets. Hearing loss gene panels offer comprehensive genetic testing for hereditary hearing loss, and advancements in sequencing technology have made genetic testing more accessible and affordable. Currently, genetic panel tests available at a relatively lower cost are offered to patients who face financial barriers. In this study, clinical and audiometric data were collected from six pediatric patients who underwent genetic panel testing. Known pathogenic variants in MYO15A, GJB2, and USH2A were most likely to be causal of hearing loss. Novel pathogenic variants in the MYO7A and TECTA genes were also identified. Variable hearing phenotypes and inheritance patterns were observed amongst individuals with different pathogenic variants. The identification of these variants contributes to the continually expanding knowledge base on genetic hearing loss and lays the groundwork for personalized treatment options in the future.

Assessing Neural Synchrony in the Cochlear Nerve to Electrical Stimulation in Children With Auditory Neuropathy Spectrum Disorder.

OBJECTIVES: This study reported phase locking values (PLVs) that quantified the trial-to-trial phase coherence of electrically evoked compound action potentials in children with auditory neuropathy spectrum disorders (ANSD) and children with Gap Junction Beta 2 (GJB2) mutations, a patient population without noticeable cochlear nerve damage. DESIGN: PLVs were measured at three electrode locations in 11 children with ANSD and 11 children with GJB2 mutations. Smaller PLVs indicated poorer neural synchrony. A linear mixed-effects model was used to compare PLVs measured at different electrode locations between participant groups. RESULTS: After controlling for the stimulation level effect, children with ANSD had smaller PLVs than children with GJB2 mutations at all three electrode locations. CONCLUSIONS: Cochlear-implanted children with ANSD show poorer peripheral neural synchrony than children with GJB2 mutations.

Expressive vocabulary word categories of children who are deaf and hard-of-hearing.

This study investigated the acquisition of early expressive vocabulary among young children who are deaf and hard-of-hearing (DHH; n = 68) using auditory technology (hearing aids and cochlear implants). Parents completed a standardized vocabulary checklist, which allowed analyses of (i) the size of their child's spoken vocabulary; (ii) composition of the expressive lexicon (e.g., parts of speech such as nouns and verbs; semantic categories such as routines and body parts); and (iii) demographic and audiologic factors (e.g., chronologic age, degree of hearing access) potentially associated with these metrics. Young children who are DHH and use auditory technology acquired fewer spoken words than peers with typical hearing (TH) matched for chronologic age but more spoken words than peers with TH matched for listening experience. Action verbs-not nouns-significantly increased the odds of a child who is DHH achieving a vocabulary quotient within the normative range. These findings support the exploration of early expressive vocabulary size and composition-especially the number of active verbs-to guide clinical management and decision-making for young children who are DHH.

EEG Alpha Band Responses Reveal Amplification Benefits in Infants with Hearing Loss.

Our objective was to examine the effects of hearing aid amplification on auditory detection and discrimination in infants who were hard of hearing (IHH) using a physiological measure of auditory perception. We recorded EEG from 41 sleeping IHH aged 1.04 to 5.62 months while presenting auditory stimuli in a mismatch response paradigm. Responses were recorded during two listening conditions for each participant: aided and unaided. Temporal envelopes of the mismatch response in the EEG alpha band (6-12 Hz) were extracted from the latent, time-frequency transformed data. Aided alpha band responses were greater than unaided responses for the deviant trials but were not different for the standard trials. Responses to the deviant trials were greater than responses to the standard trials for the aided conditions but were not different for the unaided conditions. These results suggest that the alpha band mismatch can be used to examine both detection and discrimination of speech and non-speech sounds in IHH. With further study, the alpha band mismatch could expand and refine our abilities to validate hearing aid fittings at younger ages than current clinical protocols allow.

Speech Discrimination in Infancy Predicts Language Outcomes at 30 Months for Both Children with Normal Hearing and Those with Hearing Differences.

BACKGROUND: Speech discrimination assessments are used to validate amplification fittings of older children who are hard of hearing (CHH). Unfortunately, speech discrimination is not assessed clinically ≤24 months and in turn no studies have investigated the relationship between speech discrimination during infancy and later language development among CHH. OBJECTIVE: To examine the relationship between an individual infant's speech discrimination measured at 9 months and their expressive/receptive spoken language at 30 months for children with normal hearing (CNH) and CHH. METHODS: Behavioral speech discrimination was assessed at 9 months and language assessments were conducted at 16, 24, and 30 months using a parent questionnaire, and at 30 months using the Mullen Scales of Early Learning among 90 infants (49 CNH; 41 CHH). RESULTS: Conditioned Head Turn (CHT) performance for /a-i/ significantly predicted expressive and receptive language at 30 months across both groups. Parental questionnaires were also predictive of later language ability. No significant differences in speech discrimination or language outcomes between CNH and CHH were found. CONCLUSIONS: This is the first study to document a positive relationship between infant speech discrimination and later language abilities in both early-identified CHH and CNH.

American Cochlear Implant Alliance Task Force Guidelines for Determining Cochlear Implant Candidacy in Children.

This article summarizes the available evidence on pediatric cochlear implantation to provide current guidelines for clinical protocols and candidacy recommendations in the United States. Candidacy determination involves specification of audiologic and medical criteria per guidelines of the Food and Drug Administration. However, recommendations for a cochlear implant evaluation also should maintain flexibility and consider a child's skill progression (i.e., month-for-month progress in speech, language, and auditory development) and quality of life with appropriately fit hearing aids. Moreover, evidence supports medical and clinical decisions based on other factors, including (a) ear-specific performance, which affords inclusion of children with asymmetric hearing loss and single-sided deafness as implant candidates; (b) ear-specific residual hearing, which influences surgical technique and device selection to optimize hearing; and (c) early intervention to minimize negative long-term effects on communication and quality of life related to delayed identification of implant candidacy, later age at implantation, and/or limited commitment to an audiologic rehabilitation program. These evidence-based guidelines for current clinical protocols in determining pediatric cochlear implant candidacy encourage a team-based approach focused on the whole child and the family system.

Relationship between Behavioral Infant Speech Perception and Hearing Age for Children with Hearing Loss.

(1) Background: Research has demonstrated that early intervention for children who are hard-of-hearing (CHH) facilitates improved language development. Early speech perception abilities may impact CHH outcomes and guide future intervention. The objective of this study was to examine the use of a conditioned head turn (CHT) task as a measure of speech discrimination in CHH using a clinically feasible protocol. (2) Methods: Speech perception was assessed for a consonant and vowel contrast among 57 CHH and 70 children with normal hearing (CNH) aged 5-17 months using a CHT paradigm. (3) Results: Regardless of hearing status, 74% of CHH and 77% of CNH could discriminate /a-i/, and 55% of CHH and 56% of CNH could discriminate /ba-da/. Regression models revealed that both CHH and CNH performed better on /ba-da/ at 70 dBA compared to 50 dBA. Performance by hearing age showed no speech perception differences for CNH and children with mild hearing loss for either contrast. However, children with hearing losses ≥ 41 dB HL performed significantly poorer than CNH for /a-i/. (4) Conclusions: This study demonstrates the clinical feasibility of assessing early speech perception in infants with hearing loss and replicates previous findings of speech perception abilities among CHH and CNH.

Population-based otoscopic and audiometric assessment of a birth cohort recruited for a pneumococcal vaccine trial 15-18 years earlier: a protocol.

INTRODUCTION: A cohort of 12 000 children in the Philippines who had enrolled in a 2000-2004 (current ages 16 to 20 years) Phase 3 11-valent pneumococcal conjugate vaccine for the prevention of radiographically confirmed pneumonia are now being asked to participate in a separate study (expected completion date September 2021) to assess the cohort's current long-term audiometric and otologic status. This new study would allow assessments of the utility of the pneumococcal vaccine in conferring its protective effects on the long-term sequelae of otitis media (OM), if any. Lack of trained local healthcare providers in otolaryngology/audiology and testing equipment in Bohol, Philippines, necessitates the development of a distinct methodology that would lead to meaningful data analysis. METHODS AND ANALYSIS: Reliable data collection and transfer are achieved by a US otolaryngologist/audiologist team training local nurses on all procedures in a didactic and hands-on process. An assortment of portable otolaryngologic and audiologic equipment suitable for field testing has been acquired, including an operating otoscope (Welch-Allyn), a video-otoscope (JedMed), a tympanometer with distortion product otoacoustic emission measurements (Path Sentiero) and a screening audiometer (HearScreen). Data will then be uploaded to a Research Electronic Data Capture database in the USA.Tympanometric and audiologic data will be codified through separate conventional algorithms. A team of paediatric otolaryngology advanced practice providers (APPs) have been trained and validated in interpreting video otoscopy. The protocol for classification of diagnostic outcome variables based on video otoscopy and tympanometry has been developed and is being used by APPs to evaluate all otoscopy data. ETHICS AND DISSEMINATION: The study was approved by the Research Institute of Tropical Medicine, Alabang, Manila, Philippines, and the institutional review board and the Colorado Multiple Institutional Review Board of the University of Colorado School of Medicine, Aurora, Colorado, USA.Research results will be made available to children and their caregivers with abnormal audiologic outcomes, the funders and other researchers. TRIAL REGISTRATION NUMBER: ISRCTN 62323832; Post-results.

Mismatched response predicts behavioral speech discrimination outcomes in infants with hearing loss and normal hearing.

Children with hearing loss (HL) remain at risk for poorer language abilities than normal hearing (NH) children despite targeted interventions; reasons for these differences remain unclear. In NH children, research suggests speech discrimination is related to language outcomes, yet we know little about it in children with HL under the age of 2 years. We utilized a vowel contrast, /a-i/, and a consonant-vowel contrast, /ba-da/, to examine speech discrimination in 47 NH infants and 40 infants with HL. At Mean age =3 months, EEG recorded from 11 scalp electrodes was used to compute the time-frequency mismatched response (TF-MMRSE ) to the contrasts; at Mean age =9 months, behavioral discrimination was assessed using a head turn task. A machine learning (ML) classifier was used to predict behavioral discrimination when given an arbitrary TF-MMRSE as input, achieving accuracies of 73% for exact classification and 92% for classification within a distance of one class. Linear fits revealed a robust relationship regardless of hearing status or speech contrast. TF-MMRSE responses in the delta (1-3.5 Hz), theta (3.5-8 Hz), and alpha (8-12 Hz) bands explained the most variance in behavioral task performance. Our findings demonstrate the feasibility of using TF-MMRSE to predict later behavioral speech discrimination.

Early Vocabulary Profiles of Young Deaf Children Who Use Cochlear Implants.

Purpose This study examined vocabulary profiles in young cochlear implant (CI) recipients and in children with normal hearing (NH) matched on receptive vocabulary size to improve our understanding of young CI recipients' acquisition of word categories (e.g., common nouns or closed-class words). Method We compared receptive and expressive vocabulary profiles between young CI recipients (n = 48; mean age at activation = 15.61 months, SD = 4.20) and children with NH (n = 48). The two groups were matched on receptive vocabulary size as measured by the MacArthur-Bates Communicative Development Inventories (Fenson et al., 2006): Words and Gestures form. The CI group had, on average, 8.98 months of hearing experience. The mean chronological age at completing the MacArthur-Bates Communicative Development Inventories was 23.99 months (SD = 5.14) for the CI group and 13.72 months (SD = 1.50) for the NH group. Results The CI group had a larger expressive vocabulary size than the receptive vocabulary size-matched NH group. The larger expressive vocabulary size was associated with the group difference in social words but not with common nouns. The analyses for predicate words and closed-class words included only children who produced the target categories. The CI group had a larger proportion of predicate words than the NH group, but no difference was found in closed-class words in expressive vocabulary. Conclusions Differences found in expressive vocabulary profiles may be affected by spoken vocabulary size and their age. A further examination is warranted using language samples to understand the effect of language input on children's vocabulary profiles.

Protocol for Rapid, Accurate, Electrophysiologic, Auditory Assessment of Infants and Toddlers.

BACKGROUND: Audiologists often lack confidence in results produced by current protocols for diagnostic electrophysiologic testing of infants. This leads to repeat testing appointments and slow protocols which extend the time needed to complete the testing and consequently delay fitting of amplification. A recent publication (Sininger et al50) has shown how new technologies can be applied to electrophysiologic testing systems to improve confidence in results and allow faster test protocols. Average test times for complete audiogram predictions when using new technologies and protocols were found to be just over 32 minutes using auditory brainstem response (ABR) and just under 20 minutes using auditory steady-state response (ASSR) technology. PURPOSE: The purpose of this manuscript is to provide details of expedited test protocols for infant and toddler diagnostic electrophysiologic testing. SUMMARY: Several new technologies and their role in test speed and confidence are described including CE-Chirp stimuli, automated detection of ABRs using a technique called F MP, Bayesian weighting which is an alternative to standard artifact rejection and Next-Generation ASSR with improved response detection and chirp stimuli. The test protocol has the following features: (1) preliminary testing includes impedance measures and otoacoustic emissions, (2) starting test levels are based on Broad-Band CE-Chirp thresholds in each ear, (3) ABRs or ASSRs are considered present based on automated detection rather than on replication of responses, (4) number of test levels is minimized, (5) ASSR generally evaluates four frequencies in each ear simultaneously with flexibility to change all test levels independently. CONCLUSIONS: Combining new technologies with common-sense strategies has been shown to substantially reduce test times for predicting audiometric thresholds in infants and toddlers (Sininger et al50). Details and rationales for changing test strategies and protocols are given and case examples are used to illustrate.

Meeting the Joint Committee on Infant Hearing Standards in a Large Metropolitan Children's Hospital: Barriers and Next Steps.

Purpose The aim of this study was to determine how a large metropolitan children's hospital's practices align with the Joint Committee on Infant Hearing (JCIH) 1-3-6 guidelines (diagnose hearing loss by 3 months of age, fitted with hearing aids within 1 month of diagnosis, and enroll in early intervention by 6 months of age) and examine variables that have impacted meeting these guidelines. This hospital is not a birthing hospital. Therefore, the first recommendation (hearing screen by 1 month of age) was not evaluated. Method One hundred forty-one auditory evoked potential evaluations for infants under the age of 6 months were reviewed for this study. Data were only gathered for infants identified with a bilateral hearing loss ( n = 34). The following was recorded: degree of hearing loss, number of diagnostic sessions over time, the percentage of infants who transitioned to hearing aid fittings, and the age at which JCIH benchmarks were accomplished. Results Sixty-two percent of infants were diagnosed with hearing loss by 3 months of age, 48% of infants were fitted with hearing aids by 4 months of age, and the average age of infants enrolled in early intervention was 4.58 months. Seventy percent of infants were fitted within 1 month of the diagnosis of hearing loss. The identified variables that led to the hearing aids being fitted greater than 1 month after the diagnosis are as follows: cancellations/missed appointments, middle ear involvement, and mild hearing loss. Conclusions Results of this internal audit revealed opportunities for growth in better meeting and exceeding JCIH recommendations of diagnosis by 3 months of age and hearing aid fitting within 1 month of diagnosis. Adjustments in the scheduling process and appointment options have been implemented in response to these results. Additional examination of why these recommendations are not being met and what can be done to achieve them is needed.

Large-scale otoscopic and audiometric population assessment: A pilot study.

OBJECTIVE: Large-scale otoscopic and audiometric assessment of populations is difficult due to logistic impracticalities, particularly in low- and middle-income countries (LMIC). We report a novel assessment methodology based on training local field workers, advances in audiometric testing equipment and cloud-based technology. METHODS: Prospective observational study in Bohol, Philippines. A U.S. otolaryngologist/audiologist team trained 5 local nurses on all procedures in a didactic and hands-on process. An operating otoscope (Welch-AllynR) was used to clear cerumen and view the tympanic membrane, images of which were recorded using a video otoscope (JedMedR). Subjects underwent tympanometry and distortion product otoacoustic emission (DPOAE) (Path SentieroR), and underwent screening audiometry using noise cancelling headphones and a handheld Android device (HearScreenR). Sound-booth audiometry was reserved for failed subjects. Data were uploaded to a REDCap database. Teenage children previously enrolled in a 2000-2004 Phase 3 pneumococcal conjugate vaccine trial, were the subjects of the trainees. RESULTS: During 4 days of training, 47 Filipino children (M/F = 28/19; mean/median age = 14.6/14.6 years) were the subjects of the trainee nurses. After the training, all nurses could perform all procedures independently. Otoscopic findings by ears included: normal (N = 77), otitis media with effusion (N = 2), myringosclerosis (N = 5), healed perforation (N = 6), perforation (N = 2) and retraction pocket/cholesteatoma (N = 2). Abnormal audiometric findings included: tympanogram (N = 4), DPOAE (N = 4) and screening audiometry (N = 0). CONCLUSION: Training of local nurses has been shown to be robust and this methodology overcomes challenges of distant large-scale population otologic/audiometric assessment.

The relationship between mismatch response and the acoustic change complex in normal hearing infants.

OBJECTIVE: To examine the utility of the mismatch response (MMR) and acoustic change complex (ACC) for assessing speech discrimination in infants. METHODS: Continuous EEG was recorded during sleep from 48 (24 male, 20 female) normally hearing aged 1.77 to -4.57 months in response to two auditory discrimination tasks. ACC was recorded in response to a three-vowel sequence (/i/-/a/-/i/). MMR was recorded in response to a standard vowel, /a/, (probability 85%), and to a deviant vowel, /i/, (probability of 15%). A priori comparisons included: age, sex, and sleep state. These were conducted separately for each of the three bandpass filter settings were compared (1-18, 1-30, and 1-40 Hz). RESULTS: A priori tests revealed no differences in MMR or ACC for age, sex, or sleep state for any of the three filter settings. ACC and MMR responses were prominently observed in all 44 sleeping infants (data from four infants were excluded). Significant differences observed for ACC were to the onset and offset of stimuli. However, neither group nor individual differences were observed to changes in speech stimuli in the ACC. MMR revealed two prominent peaks occurring at the stimulus onset and at the stimulus offset. Permutation t-tests revealed significant differences between the standard and deviant stimuli for both the onset and offset MMR peaks (p < 0.01). The 1-18 Hz filter setting revealed significant differences for all participants in the MMR paradigm. CONCLUSION: Both ACC and MMR responses were observed to auditory stimulation suggesting that infants perceive and process speech information even during sleep. Significant differences between the standard and deviant responses were observed in the MMR, but not ACC paradigm. These findings suggest that the MMR is sensitive to detecting auditory/speech discrimination processing. SIGNIFICANCE: This paper identified that MMR can be used to identify discrimination in normal hearing infants. This suggests that MMR has potential for use in infants with hearing loss to validate hearing aid fittings.

Evaluation of Speed and Accuracy of Next-Generation Auditory Steady State Response and Auditory Brainstem Response Audiometry in Children With Normal Hearing and Hearing Loss.

OBJECTIVES: The first objective of this study was to compare the predicted audiometric thresholds obtained by auditory steady state response (ASSR) and auditory brainstem response (ABR) in infants and toddlers when both techniques use optimal stimuli and detection algorithms. This information will aid in determining the basis for large discrepancies in ABR and ASSR measures found in past studies. The hypothesis was that advancements in ASSR response detection would improve (lower) thresholds and decrease discrepancies between the thresholds produced by the two techniques. The second objective was to determine and compare test times required by the two techniques to predict thresholds for both ears at the 4 basic audiometric frequencies of 500, 1000, 2000, and 4000 Hz. DESIGN: A multicenter clinical study was implemented at three university-based children's hospital audiology departments. Participants were 102 infants and toddlers referred to the centers for electrophysiologic testing for audiometric purposes. The test battery included wideband tympanometry, distortion-product otoacoustic emissions, and threshold measurements at four frequencies in both ears using ABR and ASSR (randomized) as implemented on the Interacoustics Eclipse systems with "Next-Generation" ASSR detection and FMP analysis for ABR. Both methods utilized narrow band CE-Chirp stimuli. Testers were trained on a specialized test battery designed to minimize test time for both techniques. Testing with both techniques was performed in one session. Thresholds were evaluated and confirmed by the first author and correction factors were applied. Test times were documented in system software. RESULTS: Corrected thresholds for ABR and ASSR were compared by regression, by the Bland-Altman technique and by matched pairs t tests. Thresholds were significantly lower for ASSR than ABR. The ABR-ASSR discrepancy at 500 Hz was 14.39 dB, at 1000 Hz was 10.12 dB, at 2000 Hz was 3.73 dB, and at 4000 Hz was 3.67 dB. The average test time for ASSR of 19.93 min (for 8 thresholds) was found to be significantly lower (p < 0.001) than the ABR test time of 32.15 min. One half of the subjects were found to have normal hearing. ASSR thresholds plotted in dB nHL for normal-hearing children in this study were found to be the lowest yet described except for one study which used the same technology. CONCLUSIONS: This study found a reversal of previous findings with up to 14 dB lower thresholds found when using the ASSR technique with "Next-Generation" detection as compared with ABR using an automated detection (FMP). The test time for an audiogram prediction was significantly lower when using ASSR than ABR but was excellent by clinical standards for both techniques. ASSRs improved threshold performance was attributed to advancements in response detection including utilization of information at multiple harmonics of the modulation frequency. The stimulation paradigm which utilized narrow band CE-Chirps also contributed to the low absolute levels of the thresholds in nHL found with both techniques.

Spectral-temporal EEG dynamics of speech discrimination processing in infants during sleep.

BACKGROUND: Oddball paradigms are frequently used to study auditory discrimination by comparing event-related potential (ERP) responses from a standard, high probability sound and to a deviant, low probability sound. Previous research has established that such paradigms, such as the mismatch response or mismatch negativity, are useful for examining auditory processes in young children and infants across various sleep and attention states. The extent to which oddball ERP responses may reflect subtle discrimination effects, such as speech discrimination, is largely unknown, especially in infants that have not yet acquired speech and language. RESULTS: Mismatch responses for three contrasts (non-speech, vowel, and consonant) were computed as a spectral-temporal probability function in 24 infants, and analyzed at the group level by a modified multidimensional scaling. Immediately following an onset gamma response (30-50 Hz), the emergence of a beta oscillation (12-30 Hz) was temporally coupled with a lower frequency theta oscillation (2-8 Hz). The spectral-temporal probability of this coupling effect relative to a subsequent theta modulation corresponds with discrimination difficulty for non-speech, vowel, and consonant contrast features. DISCUSSION: The theta modulation effect suggests that unexpected sounds are encoded as a probabilistic measure of surprise. These results support the notion that auditory discrimination is driven by the development of brain networks for predictive processing, and can be measured in infants during sleep. The results presented here have implications for the interpretation of discrimination as a probabilistic process, and may provide a basis for the development of single-subject and single-trial classification in a clinically useful context. CONCLUSION: An infant's brain is processing information about the environment and performing computations, even during sleep. These computations reflect subtle differences in acoustic feature processing that are necessary for language-learning. Results from this study suggest that brain responses to deviant sounds in an oddball paradigm follow a cascade of oscillatory modulations. This cascade begins with a gamma response that later emerges as a beta synchronization, which is temporally coupled with a theta modulation, and followed by a second, subsequent theta modulation. The difference in frequency and timing of the theta modulations appears to reflect a measure of surprise. These insights into the neurophysiological mechanisms of auditory discrimination provide a basis for exploring the clinically utility of the MMR TF and other auditory oddball responses.

Pediatric Minimum Speech Test Battery.

BACKGROUND: Assessment of patient outcomes and documentation of treatment efficacy serves as an essential component of (re)habilitative audiology; however, no standardized protocol exists for the assessment of speech perception abilities for children with hearing loss. This presents a significant challenge in tracking performance of children who utilize various hearing technologies for within-subjects assessment, between-subjects assessment, and even across different facilities. PURPOSE: The adoption and adherence to a standardized assessment protocol could help facilitate continuity of care, assist in clinical decision making, allow clinicians and researchers to define benchmarks for an aggregate clinical population, and in time, aid with patient counseling regarding expectations and predictions regarding longitudinal outcomes. DESIGN: The Pediatric Minimum Speech Test Battery (PMSTB) working group-comprised of clinicians, scientists, and industry representatives-commenced in 2012 and has worked collaboratively to construct the first PMSTB, which is described here. CONCLUSIONS: Implementation of the PMSTB in clinical practice and dissemination of associated data are both critical for achieving the next level of success for children with hearing loss and for elevating pediatric hearing health care ensuring evidence-based practice for (re)habilitative audiology.