Assessment of Receptive and Expressive Language Skills Among Young Children With Prelingual Single-Sided Deafness Managed With Early Cochlear Implantation.

Importance: Pediatric single-sided deafness (SSD) can seriously affect development, causing impaired spatial hearing skills, speech-language delays, and academic underachievement. Early cochlear implantation likely improves hearing-related outcomes, but its association with language development remains unclear. Objective: To investigate whether early cochlear implantation is associated with language outcomes for children with prelingual SSD. Design, Setting, and Participants: The Cochlear Implant for Children and One Deaf Ear study was initiated in 2015 and recruited participants at 4 academic hospitals in Flanders, Belgium, through 2019. This cohort study included 3 groups of children aged 2 to 5 years: children with SSD and a cochlear implant, children with SSD without a cochlear implant, and a control group with normal hearing. Language and hearing skills were assessed 1 to 2 times per year until the age of 10 years. Study completion rates were high (82%). Data analysis was performed from October to December 2020. Exposure: Unilateral cochlear implant. Main Outcomes and Measures: Longitudinal vocabulary, grammar, and receptive language scores. The implanted group was hypothesized to outperform the nonimplanted group on all language tests. Results: During the recruitment period, 47 children with prelingual SSD without additional disabilities were identified at the participating hospitals. Fifteen of the 34 children with an intact auditory nerve received a cochlear implant (44%, convenience sample). Sixteen of the remaining children were enrolled in the SSD control group (50%). Data from 61 children (mean [SD] age at the time of enrollment, 2.08 [1.34] years; 26 girls [42%]) were included in the analysis: 15 children with SSD and a cochlear implant, 16 children with SSD without a cochlear implant, and 30 children with normal hearing. Children with SSD and a cochlear implant performed in line with their peers with normal hearing with regard to grammar. In contrast, children with SSD without a cochlear implant had worse grammar scores than the group with implants (-0.76; 95% CI, -0.31 to -1.21; P = .004) and the group with normal hearing (-0.53; 95% CI, -0.91 to -0.15; P = .02). The 3 groups had similar vocabulary and receptive language abilities. Conclusions and Relevance: These findings suggest that early cochlear implantation is associated with normal grammar development in young children with prelingual SSD. Although further follow-up will reveal the long-term outcomes of the cochlear implant for other skills, the current results will help clinicians and policy makers identify the best treatment option for these children.

The Cost of Intrinsic and Extrinsic Cognitive Demands on Auditory Functioning in Older Adults With Normal Hearing or Using Hearing Aids.

OBJECTIVES: We investigated the impact of both intrinsic and extrinsic cognitive demands on auditory and secondary task performance in older adults with normal hearing (NH) and adults using hearing aids (HAs) in an ecologically relevant listening environment. DESIGN: Fifteen adults with NH and 15 adults using HAs (60 to 72 years of age) were recruited to perform the "Audiovisual True-to-Life Assessment of Auditory Rehabilitation"-paradigm (AVATAR), which combines an auditory-visual speech-in-noise task with three secondary tasks on either auditory localization or visual short-term memory in a preload multitask paradigm. Intrinsic demands were altered by presenting speech either at equivalent speech accuracy levels of 50% correct (SPIN50%) or equivalent speech-to-noise ratios of +5dB SNR (SPIN+5dB). We manipulated the amount of extrinsic cognitive demands by including one (dual condition) or three secondary tasks (quadruple condition). Performance decrements on the secondary tasks were considered to reflect an increase in resource allocation to speech understanding and thus an increase in listening effort. In addition, we administered a cognitive test battery as well as a questionnaire on self-reported hearing difficulties and subjective measures of effort and motivation. RESULTS: Speech understanding and secondary task performance on the visual short-term memory task were lower in the SPIN50% condition compared to SPIN+5dB. Whereas speech understanding at SPIN50% was equally high in the dual and quadruple conditions, the quadruple condition resulted in lower secondary task performance on the visual short-term memory task, higher levels of self-reported effort, and lower motivation compared to the dual-task condition. The same was true for experimental conditions at SPIN+5dB. Additionally, adults with NH outperformed adults using HAs on speech understanding, auditory localization, and self-reported hearing abilities, but no group differences were observed on secondary task costs or cognitive measures. CONCLUSIONS: This study showed that, irrespective of the hearing status of the listener, speech performance was not affected by the amount of extrinsic cognitive demands, but was worse and required more effort under conditions with a more negative SNR. Also, increasing the extrinsic cognitive demands resulted in lower performance on one of the secondary tasks, suggesting that more complex listening environments require more effort. Although adults with NH outperformed HA users on speech understanding and auditory localization, the two groups did not differ with respect to secondary task costs.

Electrophysiological assessment of temporal envelope processing in cochlear implant users.

Cochlear-implant (CI) users rely on temporal envelope modulations (TEMs) to understand speech, and clinical outcomes depend on the accuracy with which these TEMs are encoded by the electrically-stimulated neural ensembles. Non-invasive EEG measures of this encoding could help clinicians identify and disable electrodes that evoke poor neural responses so as to improve CI outcomes. However, recording EEG during CI stimulation reveals huge stimulation artifacts that are up to orders of magnitude larger than the neural response. Here we used a custom-built EEG system having an exceptionally high sample rate to accurately measure the artefact, which we then removed using linear interpolation so as to reveal the neural response during continuous electrical stimulation. In ten adult CI users, we measured the 40-Hz electrically evoked auditory steady-state response (eASSR) and electrically evoked auditory change complex (eACC) to amplitude-modulated 900-pulses-per-second pulse trains, stimulated in monopolar mode (i.e. the clinical default), and at different modulation depths. We successfully measured artifact-free 40-Hz eASSRs and eACCs. Moreover, we found that the 40-Hz eASSR, in contrast to the eACC, showed substantial responses even at shallow modulation depths. We argue that the 40-Hz eASSR is a clinically feasible objective measure to assess TEM encoding in CI users.

Age Affects Speech Understanding and Multitask Costs.

OBJECTIVES: We examined the effect of age on speech understanding and multitask costs in the ecologically relevant "Audiovisual True-to-Life Assessment of Auditory Rehabilitation"-paradigm (AVATAR). DESIGN: Twenty-nine normal-hearing middle-aged adults completed AVATAR, which combines an auditory-visual speech-in-noise task with three secondary tasks on auditory localization or visual short-term memory in different dual-, triple-, and quadruple-task combinations. Performance decrements on the secondary tasks were considered to reflect the cognitive resources allocated during listening. Self-reported hearing difficulties were administered via a questionnaire. Results were compared with scores of 35 young normal-hearing adults. RESULTS: Middle-aged adults performed consistently worse than young adults on speech understanding and, in the triple- and quadruple-task combinations only, on secondary task performance. Furthermore, middle-agers reported higher levels of daily listening concentration and more difficulties with speech understanding. CONCLUSIONS: This study demonstrated the adverse effect of age on speech-in-noise understanding and the amount of allocated cognitive resources during challenging listening situations realized in AVATAR.

AVATAR Assesses Speech Understanding and Multitask Costs in Ecologically Relevant Listening Situations.

OBJECTIVES: There is a high need among clinicians and researchers for an ecologically valid measure of auditory functioning and listening effort. Therefore, we developed AVATAR: an "Audiovisual True-to-life Assessment of Auditory Rehabilitation" which takes important characteristics of real-life listening situations into account, such as multimodal speech presentation, spatial separation of sound sources and multitasking. As such, AVATAR aims to assess both auditory functioning and the amount of allocated processing resources during listening in a realistic yet controllable way. In the present study, we evaluated AVATAR and investigated whether speech understanding in noise and multitask costs during realistic listening environments changed with increasing task complexity. DESIGN: Thirty-five young normal-hearing participants performed different task combinations of an auditory-visual speech-in-noise task and three secondary tasks on both auditory localization and visual short-term memory in a simulated restaurant environment. Tasks were combined in increasing complexity and multitask costs on the secondary tasks were investigated as an estimate of the amount of cognitive resources allocated during listening and multitasking. In addition to behavioral measures of auditory functioning and effort, working memory capacity and self-reported hearing difficulties were established using a reading span test and a questionnaire on daily hearing abilities. RESULTS: Whereas performance on the speech-in-noise task was not affected by task complexity, multitask costs on one of the secondary tasks became significantly larger with increasing task complexity. Working memory capacity correlated significantly with multitask costs, but no association was observed between behavioral outcome measures and self-reported hearing abilities or effort. CONCLUSIONS: AVATAR proved to be a promising model to assess speech intelligibility and auditory localization abilities and to gauge the amount of processing resources during effortful listening in ecologically relevant multitasking situations by means of multitask costs. In contrast with current clinical measures of auditory functioning, results showed that listening and multitasking in challenging listening environments can require a considerable amount of processing resources, even for young normal-hearing adults. Furthermore, the allocation of resources increased in more demanding listening situations. These findings open avenues for a more realistic assessment of auditory functioning and individually tuned auditory rehabilitation for individuals of different age and hearing profiles.

Diffusion tensor imaging and resting-state functional MRI-scanning in 5- and 6-year-old children: training protocol and motion assessment.

Advanced Magnetic Resonance Imaging (MRI) techniques such as Diffusion Tensor Imaging (DTI) and resting-state functional MRI (rfMRI) are widely used to study structural and functional neural connectivity. However, as these techniques are highly sensitive to motion artifacts and require a considerable amount of time for image acquisition, successful acquisition of these images can be challenging to complete with certain populations. This is especially true for young children. This paper describes a new approach termed the 'submarine protocol', designed to prepare 5- and 6-year-old children for advanced MRI scanning. The submarine protocol aims to ensure that successful scans can be acquired in a time- and resource-efficient manner, without the need for sedation. This manuscript outlines the protocol and details its outcomes, as measured through the number of children who completed the scanning procedure and analysis of the degree of motion present in the acquired images. Seventy-six children aged between 5.8 and 6.9 years were trained using the submarine protocol and subsequently underwent DTI and rfMRI scanning. After completing the submarine protocol, 75 of the 76 children (99%) completed their DTI-scan and 72 children (95%) completed the full 35-minute scan session. Results of diffusion data, acquired in 75 children, showed that the motion in 60 of the scans (80%) did not exceed the threshold for excessive motion. In the rfMRI scans, this was the case for 62 of the 71 scans (87%). When placed in the context of previous studies, the motion data of the 5- and 6-year-old children reported here were as good as, or better than those previously reported for groups of older children (i.e., 8-year-olds). Overall, this study shows that the submarine protocol can be used successfully to acquire DTI and rfMRI scans in 5 and 6-year-old children, without the need for sedation or lengthy training procedures.

Objective assessment of frequency-specific hearing thresholds in babies.

OBJECTIVE: To report on clinical experience using dichotic multiple-stimulus auditory steady-state responses (ASSRs) as an objective technique to estimate frequency-specific hearing thresholds in hearing-impaired infants. METHODS: A comparison was made between the click-evoked auditory brainstem response (ABR), auditory steady-state responses and behavioral hearing thresholds (BHTs). Both ears of 10 infants between 3 and 14 months of age were tested. ABR and ASSRs were recorded during the same test session. ABR was evoked by 100 micros clicks. ASSRs were evoked by amplitude- and frequency-modulated tones with carrier frequencies of 0.5, 1, 2 and 4 kHz and modulation frequencies ranging from 82 to 110 Hz. Eight signals (four to each ear) were presented simultaneously. ASSR thresholds were derived after separate recordings of approximately 5, 7.5 and 10 min to compare the influence of test duration. BHTs were defined in later test sessions as soon as possible after the ASSR test, dependent on medical and developmental factors. RESULTS: For the subjects tested in this study 60% of ABR thresholds and 95% of ASSR thresholds for 1, 2 and 4 kHz were found at an average age of 7 months. Only 51% of frequency-specific BHTs could be obtained but on average 5 months later. The correlation of ABR thresholds and ASSR thresholds at 2 kHz was 0.77. The correlation of ASSRs and BHTs was 0.92. The mean differences and associated standard deviations were 4 +/- 14, 4 +/- 11, -2 +/- 14 and -1 +/- 13 dB for 0.5, 1, 2 and 4 kHz, respectively. The average test duration was 45 min for ABR (one threshold in both ears) and 58 min for ASSR (four thresholds in both ears). By reducing the duration of the separate recordings of ASSR, the precision of the hearing threshold estimate decreased and the number of outlying and missing values increased. Correlation coefficients were 0.92, 0.89 and 0.83 for recordings of maximum 10, 7.5 and 5 min, respectively. A compromise between test duration and precision has to be sought. CONCLUSIONS: Multiple-frequency ASSRs offer the possibility to estimate frequency-specific hearing thresholds in babies in a time-efficient way.

Hearing assessment by recording multiple auditory steady-state responses: the influence of test duration.

The influence of test duration on the precision of hearing thresholds estimated by recording multiple auditory steady-state responses (ASSRs) was investigated. ASSR thresholds at four frequencies in both ears were assessed in 10 normal-hearing and 10 hearing-impaired subjects. The precision of the estimated hearing thresholds was compared for ASSR recordings of 5, 10 and 15 min per intensity level, corresponding to total test durations of approximately 30, 55 and 70 min for hearing-impaired ears. Furthermore, an intensity step size of 10 dB was compared to a step size of 5 dB. The mean difference scores averaged over the four frequencies were 15 +/- 10, 12 +/- 9 and 11 +/- 8 dB after recordings of 5, 10 and 15 min respectively. The corresponding Pearson correlation coefficients were 0.93, 0.95 and 0.96. Increasing the length of the separate recordings increases the precision of the estimates, independent of tested frequency. A compromise between both will have to be made. With a total test duration of approximately 1 h, four hearing thresholds in both ears can be estimated with a standard error of the estimate of 8 dB.