What factors are associated with infant hearing aid use? A parent survey using the Theoretical Domains Framework.

OBJECTIVE: Hearing aid use is lowest in 0-3-year-olds with hearing loss, placing spoken language development at risk. Existing interventions lack effectiveness and are typically not based on a theoretically driven, comprehensive understanding of the factors influencing infant hearing aid use. The present study is the first to address this gap in understanding. DESIGN AND STUDY SAMPLE: A 55-item online survey based on the Theoretical Domains Framework (TDF) was completed by 56 parents of 0-3-year-old hearing aid users. RESULTS: Participants reported a wide range of barriers across TDF domains, which were associated with parent-reported hearing aid use and more pronounced in parents of lower hearing aid users. The most strongly reported domains across participants were "emotion" (e.g. feelings of worry when using hearing aids), "beliefs about capabilities" (e.g. belief in ability to use hearing aids consistently), and "environmental context and resources" (e.g. child removing hearing aids). CONCLUSIONS: Parents report a wider range of barriers to infant hearing aid use than existing investigations suggest and current interventions address. Interventions would benefit from: (i) targeting a wider range of TDF domains in their design; and (ii) implementing the present TDF survey to identify and target family-specific barriers to infant hearing aid use.

Aided Cortical Auditory Evoked Potentials in Infants With Frequency-Specific Synthetic Speech Stimuli: Sensitivity, Repeatability, and Feasibility.

OBJECTIVES: The cortical auditory evoked potential (CAEP) test is a candidate for supplementing clinical practice for infant hearing aid users and others who are not developmentally ready for behavioral testing. Sensitivity of the test for given sensation levels (SLs) has been reported to some degree, but further data are needed from large numbers of infants within the target age range, including repeat data where CAEPs were not detected initially. This study aims to assess sensitivity, repeatability, acceptability, and feasibility of CAEPs as a clinical measure of aided audibility in infants. DESIGN: One hundred and three infant hearing aid users were recruited from 53 pediatric audiology centers across the UK. Infants underwent aided CAEP testing at age 3 to 7 months to a mid-frequency (MF) and (mid-)high-frequency (HF) synthetic speech stimulus. CAEP testing was repeated within 7 days. When developmentally ready (aged 7-21 months), the infants underwent aided behavioral hearing testing using the same stimuli, to estimate the decibel (dB) SL (i.e., level above threshold) of those stimuli when presented at the CAEP test sessions. Percentage of CAEP detections for different dB SLs are reported using an objective detection method (Hotellings T 2 ). Acceptability was assessed using caregiver interviews and a questionnaire, and feasibility by recording test duration and completion rate. RESULTS: The overall sensitivity for a single CAEP test when the stimuli were ≥0 dB SL (i.e., audible) was 70% for the MF stimulus and 54% for the HF stimulus. After repeat testing, this increased to 84% and 72%, respectively. For SL >10 dB, the respective MF and HF test sensitivities were 80% and 60% for a single test, increasing to 94% and 79% for the two tests combined. Clinical feasibility was demonstrated by an excellent >99% completion rate, and acceptable median test duration of 24 minutes, including preparation time. Caregivers reported overall positive experiences of the test. CONCLUSIONS: By addressing the clinical need to provide data in the target age group at different SLs, we have demonstrated that aided CAEP testing can supplement existing clinical practice when infants with hearing loss are not developmentally ready for traditional behavioral assessment. Repeat testing is valuable to increase test sensitivity. For clinical application, it is important to be aware of CAEP response variability in this age group.

Modified T2 Statistics for Improved Detection of Aided Cortical Auditory Evoked Potentials in Hearing-Impaired Infants.

The cortical auditory evoked potential (CAEP) is a change in neural activity in response to sound, and is of interest for audiological assessment of infants, especially those who use hearing aids. Within this population, CAEP waveforms are known to vary substantially across individuals, which makes detecting the CAEP through visual inspection a challenging task. It also means that some of the best automated CAEP detection methods used in adults are probably not suitable for this population. This study therefore evaluates and optimizes the performance of new and existing methods for aided (i.e., the stimuli are presented through subjects' hearing aid(s)) CAEP detection in infants with hearing loss. Methods include the conventional Hotellings T2 test, various modified q-sample statistics, and two novel variants of T2 statistics, which were designed to exploit the correlation structure underlying the data. Various additional methods from the literature were also evaluated, including the previously best-performing methods for adult CAEP detection. Data for the assessment consisted of aided CAEPs recorded from 59 infant hearing aid users with mild to profound bilateral hearing loss, and simulated signals. The highest test sensitivities were observed for the modified T2 statistics, followed by the modified q-sample statistics, and lastly by the conventional Hotelling's T2 test, which showed low detection rates for ensemble sizes <80 epochs. The high test sensitivities at small ensemble sizes observed for the modified T2 and q-sample statistics are especially relevant for infant testing, as the time available for data collection tends to be limited in this population.

Longitudinal assessment of listening skills in UK infants with hearing aids using the LittlEARS® auditory questionnaire.

OBJECTIVE: To investigate listening skills in infant hearing aid users using the LittlEARS® Auditory Questionnaire (LEAQ). DESIGN: Caregivers completed the LEAQ, and hearing aid data logging was recorded, at infant age 3-7 months and 7-21 months. STUDY SAMPLE: Seventy infant hearing aid users with permanent bilateral hearing loss, no developmental comorbidities, aged 3-7 months at first visit. RESULTS: Infants with mild and moderate losses tended to have scores within the normative range at the early time point (88%), but 29% were below the normative range when older. Thirty percent of infants with severe hearing loss were outside the normative range at the early time point and 60% outside the normative range when older. Infants with profound loss were almost always (95%) outside the normative range. At the later time point, and for infants with severe-to-profound loss, low LEAQ scores were associated with fewer daily hours hearing aid use. Scores were poorer than previous reports in the literature for infant hearing aid users. CONCLUSIONS: This study provides further knowledge on infant listening performance and hearing aid use over time that can be used to guide management of individual cases and to develop and audit service quality improvements.

Patient and public involvement in hearing research: opportunities, impact and reflections with case studies from the Manchester Centre for Audiology and Deafness.

OBJECTIVE: Patient and public involvement (PPI) in research improves relevance to end users and improves processes including recruitment participants. PPI in our research has gone from being non-existent to ubiquitous over a few years. We provide critical reflections on the benefits and challenges of PPI. DESIGN: Case studies are reported according to a modified GRIP2 framework; the aims, methodology, impact of PPI and critical reflections on each case and our experiences with PPI in general. STUDY SAMPLE: We report five UK projects that included PPI from teenagers, families, people living with dementia, autistic people, and people from South Asian and d/Deaf communities. RESULTS: Our experience has progressed from understanding the rationale to grappling methodologies and integrating PPI in our research. PPI took place at all stages of research, although commonly involved input to design including recruitment and development of study materials. Methodologies varied between projects, including PPI co-investigators, advisory panels and online surveys. CONCLUSION: On-going challenges include addressing social exclusion from research for people that lack digital access following increasing on-line PPI and involvement from underserved communities. PPI was initially motivated by funders; however the benefits have driven widespread PPI, ensuring our research is relevant to people living with hearing loss.

Longitudinal Changes in Hearing Aid Use and Hearing Aid Management Challenges in Infants.

OBJECTIVE: If the benefits of newborn hearing screening and early intervention are to be fully realized, there is a need to understand the challenges of hearing aid management in infants. The aim was to investigate longitudinal changes in hearing aid use and hearing aid management challenges in very young infants. DESIGN: Eighty-one primarily female (99%) caregivers of infant hearing aid users completed a questionnaire about hearing aid management experiences, first when their infants were 3 to 7 months old (1 to 6 months after hearing aid fitting) and again at 7 to 21 months of age. Hearing aid data logging was compared with caregiver reports of daily use for 66 infants. RESULTS: The main hearing aid management challenges reported by caregivers were performing listening checks and troubleshooting. These challenges reduced over the approximately 5-month time period but remained a problem with around a quarter of respondents still not confident or unsure about troubleshooting, and around a third not performing a daily listening check. Mean daily hearing aid use, obtained from data logging, declined significantly over time from 6.6 to 5.3 hours. Further analysis revealed reduced hearing aid use was primarily among infants with profound losses (n = 11). Caregivers overestimated daily hours of use at both time points. Caregivers reported difficulty with the infants pulling out their hearing aids, especially at the later time point. CONCLUSIONS: The findings from this relatively large sample of caregivers of young infants, assessed at two time points, revealed significant challenges in hearing aid management, including highly variable daily hearing aid use. Interventions that use behavior change techniques may be needed to ensure intentions are consistently turned into successful actions, if the benefits of newborn hearing screening and early intervention are to be fully realized.

Efficient Detection of Cortical Auditory Evoked Potentials in Adults Using Bootstrapped Methods.

BACKGROUND: Statistical detection methods are useful tools for assisting clinicians with cortical auditory evoked potential (CAEP) detection, and can help improve the overall efficiency and reliability of the test. However, many of these detection methods rely on parametric distributions when evaluating test significance, and thus make various assumptions regarding the electroencephalogram (EEG) data. When these assumptions are violated, reduced test sensitivities and/or increased or decreased false-positive rates can be expected. As an alternative to the parametric approach, test significance can be evaluated using a bootstrap, which does not require some of the aforementioned assumptions. Bootstrapping also permits a large amount of freedom when choosing or designing the statistical test for response detection, as the distributions underlying the test statistic no longer need to be known prior to the test. OBJECTIVES: To improve the reliability and efficiency of CAEP-related applications by improving the specificity and sensitivity of objective CAEP detection methods. DESIGN: The methods included in the assessment were Hotelling's T2 test, the Fmp, four modified q-sample statistics, and various template-based detection methods (calculated between the ensemble coherent average and some predefined template), including the correlation coefficient, covariance, and dynamic time-warping (DTW). The assessment was carried out using both simulations and a CAEP threshold series collected from 23 adults with normal hearing. RESULTS: The most sensitive method was DTW, evaluated using the bootstrap, with maximum increases in test sensitivity (relative to the conventional Hotelling's T2 test) of up to 30%. An important factor underlying the performance of DTW is that the template adopted for the analysis correlates well with the subjects' CAEP. CONCLUSION: When subjects' CAEP morphology is approximately known before the test, then the DTW algorithm provides a highly sensitive method for CAEP detection.

Impacts of face coverings on communication: an indirect impact of COVID-19.

OBJECTIVE: To understand the impact of face coverings on hearing and communication. DESIGN: An online survey consisting of closed-set and open-ended questions distributed within the UK to gain insights into experiences of interactions involving face coverings, and of the impact of face coverings on communication. SAMPLE: Four hundred and sixty members of the general public were recruited via snowball sampling. People with hearing loss were intentionally oversampled to more thoroughly assess the effect of face coverings in this group. RESULTS: With few exceptions, participants reported that face coverings negatively impacted hearing, understanding, engagement, and feelings of connection with the speaker. Impacts were greatest when communicating in medical situations. People with hearing loss were significantly more impacted than those without hearing loss. Face coverings impacted communication content, interpersonal connectedness, and willingness to engage in conversation; they increased anxiety and stress, and made communication fatiguing, frustrating and embarrassing - both as a speaker wearing a face covering, and when listening to someone else who is wearing one. CONCLUSIONS: Face coverings have far-reaching impacts on communication for everyone, but especially for people with hearing loss. These findings illustrate the need for communication-friendly face-coverings, and emphasise the need to be communication-aware when wearing a face covering.

Recording Obligatory Cortical Auditory Evoked Potentials in Infants: Quantitative Information on Feasibility and Parent Acceptability.

OBJECTIVES: With the advent of newborn hearing screening and early intervention, there is a growing interest in using supra-threshold obligatory cortical auditory evoked potentials (CAEPs) to complement established pediatric clinical test procedures. The aim of this study was to assess the feasibility, and parent acceptability, of recording infant CAEPs. DESIGN: Typically developing infants (n = 104) who had passed newborn hearing screening and whose parents expressed no hearing concerns were recruited. Testing was not possible in 6 infants, leaving 98, age range 5 to 39 weeks (mean age = 21.9, SD = 9.4). Three short duration speech-like stimuli (/m/, /g/, /t/) were presented at 65 dB SPL via a loudspeaker at 0° azimuth. Three criteria were used to assess clinical feasibility: (i) median test duration <30 min, (ii) >90% completion rate in a single test session, and (iii) >90% response detection for each stimulus. We also recorded response amplitude, latency, and CAEP signal to noise ratio. Response amplitudes and residual noise levels were compared for Fpz (n = 56) and Cz (n = 42) noninverting electrode locations. Parental acceptability was based on an 8-item questionnaire (7-point scale, 1 being best). In addition, we explored the patient experience in semistructured telephone interviews with seven families. RESULTS: The median time taken to complete 2 runs for 3 stimuli, including preparation, was 27 min (range 17 to 59 min). Of the 104 infants, 98 (94%) were in an appropriate behavioral state for testing. A further 7 became restless during testing and their results were classified as "inconclusive." In the remaining 91 infants, CAEPs were detected in every case with normal bilateral tympanograms. Detection of CAEPs in response to /m/, /g/, and /t/ in these individuals was 86%, 100%, and 92%, respectively. Residual noise levels and CAEP amplitudes were higher for Cz electrode recordings. Mean scores on the acceptability questionnaire ranged from 1.1 to 2.6. Analysis of interviews indicated that parents found CAEP testing to be a positive experience and recognized the benefit of having an assessment procedure that uses conversational level speech stimuli. CONCLUSIONS: Test duration, completion rates, and response detection rates met (or were close to) our feasibility targets, and parent acceptability was high. CAEPs have the potential to supplement existing practice in 3- to 9-month olds.

A Set of Time-and-Frequency-Localized Short-Duration Speech-Like Stimuli for Assessing Hearing-Aid Performance via Cortical Auditory-Evoked Potentials.

Short-duration speech-like stimuli, for example, excised from running speech, can be used in the clinical setting to assess the integrity of the human auditory pathway at the level of the cortex. Modeling of the cochlear response to these stimuli demonstrated an imprecision in the location of the spectrotemporal energy, giving rise to uncertainty as to what and when of a stimulus caused any evoked electrophysiological response. This article reports the development and assessment of four short-duration, limited-bandwidth stimuli centered at low, mid, mid-high, and high frequencies, suitable for free-field delivery and, in addition, reproduction via hearing aids. The durations were determined by the British Society of Audiology recommended procedure for measuring Cortical Auditory-Evoked Potentials. The levels and bandwidths were chosen via a computational model to produce uniform cochlear excitation over a width exceeding that likely in a worst-case hearing-impaired listener. These parameters produce robustness against errors in insertion gains, and variation in frequency responses, due to transducer imperfections, room modes, and age-related variation in meatal resonances. The parameter choice predicts large spectral separation between adjacent stimuli on the cochlea. Analysis of the signals processed by examples of recent digital hearing aids mostly show similar levels of gain applied to each stimulus, independent of whether the stimulus was presented in isolation, bursts, continuous, or embedded in continuous speech. These stimuli seem to be suitable for measuring hearing-aided Cortical Auditory-Evoked Potentials and have the potential to be of benefit in the clinical setting.

Cortical auditory evoked potentials as an objective measure of behavioral thresholds in cochlear implant users.

The aim of this study was to assess the suitability of using cortical auditory evoked potentials (CAEPs) as an objective tool for predicting behavioral hearing thresholds in cochlear implant (CI) users. Nine experienced adult CI users of Cochlear(™) devices participated. Behavioral thresholds were measured in CI users across apical, mid and basal electrodes. CAEPs were measured for the same stimuli (50 ms pulse trains of 900-pps rate) at a range of input levels across the individual's psychophysical dynamic range (DR). Amplitude growth functions using global field power (GFP) were plotted, and from this the CAEP thresholds were extrapolated and compared to the behavioral thresholds. Increased amplitude and decreased latency of the N1-P2 response was seen with increasing input level. A strong correlation was found between CAEP and behavioral thresholds (r = 0.93), implying that the cortical response may be more useful as an objective programming tool for cochlear implants than the auditory nerve response.

Voice gender differences and separation of simultaneous talkers in cochlear implant users with residual hearing.

Perception of a target voice in the presence of a competing talker, of same or different gender as the target, was investigated in cochlear implant users, in implant-alone and bimodal (acoustic hearing in the non-implanted ear) conditions. Recordings of two male and two female talkers acted as targets and maskers, to investigate whether bimodal benefit increased for different compared to same gender target/maskers due to increased ability to perceive and utilize fundamental frequency and spectral-shape differences. In both listening conditions participants showed benefit of target/masker gender difference. There was an overall bimodal benefit, which was independent of target/masker gender difference.

Beneficial acoustic speech cues for cochlear implant users with residual acoustic hearing.

This study investigated which acoustic cues within the speech signal are responsible for bimodal speech perception benefit. Seven cochlear implant (CI) users with usable residual hearing at low frequencies in the non-implanted ear participated. Sentence tests were performed in near-quiet (some noise on the CI side to reduce scores from ceiling) and in a modulated noise background, with the implant alone and with the addition, in the hearing ear, of one of four types of acoustic signals derived from the same sentences: (1) a complex tone modulated by the fundamental frequency (F0) and amplitude envelope contours; (2) a pure tone modulated by the F0 and amplitude contours; (3) a noise-vocoded signal; (4) unprocessed speech. The modulated tones provided F0 information without spectral shape information, whilst the vocoded signal presented spectral shape information without F0 information. For the group as a whole, only the unprocessed speech condition provided significant benefit over implant-alone scores, in both near-quiet and noise. This suggests that, on average, F0 or spectral cues in isolation provided limited benefit for these subjects in the tested listening conditions, and that the significant benefit observed in the full-signal condition was derived from implantees' use of a combination of these cues.