Project description:IntroductionIn the new revised National Institute for Health & Care Excellence (NICE, TA566, 2019) guidelines for cochlear implantation (CI) have clearly stipulated that the hearing loss must be bilateral. Prior to this revision, children and young people (CYP) with asymmetrical thresholds have been considered for unilateral CI when one ear was in audiological criteria. Children with asymmetrical hearing loss represent an important cohort of potential CI candidates, who will continue to be prevented from benefiting from CI unless evidence is produced to support implantation and maximise subsequent benefit.The aim of this study is to evaluate the 'real-life' hearing performance in a group of children who have received a unilateral CI and who have hearing thresholds in the contralateral ear that are outside the current UK NICE 2019 audiological criteria for CI. The contralateral ear will be aided using a conventional hearing aid (HA). The outcomes from this 'bimodal' group will be compared with a group of children who have received bilateral CI, and a group of children using bilateral HA, to extend the current knowledge about the different performance levels between bilateral CI, bilateral HA and bimodal hearing in CYP.Methods and analysisThirty CYP aged 6-17 years old, 10 bimodal users, 10 bilateral HA users and 10 bilateral cochlear implant users will be subjected to a test battery consisting of: (1) spatial release from masking, (2) complex pitch direction discrimination, (3) melodic identification, (4) perception of prosodic features in speech and (5) TEN test. Subjects will be tested in their optimal device modality. Standard demographic and hearing health information will be collected. In the absence of comparable published data to power the study, sample size was determined on pragmatic grounds. Tests are exploratory and for hypothesis generating purposes. Therefore, the standard criterion of p<0.05 will be used.Ethics and disseminationThis has been approved by the Health Research Authority and NHS REC within the UK (22/EM/0104). Industry funding was secured via a competitive researcher-led grant application process. Trial results will be subject to publication according to the definition of the outcome presented in this protocol.
Project description:This study directly compared the performance of a contralateral routing of signal (CROS)/bilateral routing of signal (BiCROS) and a soft-band bone-anchored hearing aid (BAHA) in patients with unilateral sensorineural hearing loss (SNHL) and assessed the relationship between hearing aid benefits and personal factors. Participants with unilateral SNHL were prospectively enrolled in the study and were tested under the following three conditions: unaided, with CROS/BiCROS, and with soft-band BAHA. Sound localization, consonant, hearing in noise, and psychoacoustic tests were performed. Pseudobinaural benefits (e.g., squelch, summation, and head shadow effect) were obtained in both the CROS/BiCROS and soft-band BAHA conditions and compared to the unaided condition. Sound localization ability was not improved in either the CROS/BiCROS condition or soft-band BAHA condition. Rather, sound localization ability was significantly decreased in the CROS/BiCROS setting. A CROS/BiCROS hearing aid and a soft-band BAHA provided additional benefit for speech-in-noise perception when target speech was directed to the impaired ear side. The CROS/BiCROS hearing aid was superior to the soft-band BAHA one in decreasing the head shadow effect, but it appeared to have a negative effect when the noise was delivered to the better ear. The positive and negative effects of CROS/BiCROS for localization and speech perception were significantly correlated with personal factors such as age, hearing threshold in the better ear, and unaided psychoacoustic performances. Despite the lack of device acclimatization, we believe that this study provides counseling information for hearing aid clinics to use in the context of patients with unilateral SNHL.
Project description:ObjectivesUnilateral hearing loss increases the risk of academic and behavioral challenges for school-aged children. Previous research suggests that remote microphone (RM) systems offer the most consistent benefits for children with unilateral hearing loss in classroom environments relative to other nonsurgical interventions. However, generalizability of previous laboratory work is limited because of the specific listening situations evaluated, which often included speech and noise signals originating from the side. In addition, early studies focused on speech recognition tasks requiring limited cognitive engagement. However, those laboratory conditions do not reflect characteristics of contemporary classrooms, which are cognitively demanding and typically include multiple talkers of interest in relatively diffuse background noise. The purpose of this study was to evaluate the potential effects of rerouting amplification systems, specifically a RM system and a contralateral routing of signal (CROS) system, on speech recognition and comprehension of school-age children in a laboratory environment designed to emulate the dynamic characteristics of contemporary classrooms. It was expected that listeners would benefit from the CROS system when the head shadow limits audibility (e.g., monaural indirect listening). It was also expected that listeners would benefit from the RM system only when the RM was near the talker of interest.DesignTwenty-one children (10 to 14 years, M = 11.86) with normal hearing participated in laboratory tests of speech recognition and comprehension. Unilateral hearing loss was simulated by presenting speech-shaped masking noise to one ear via an insert earphone. Speech stimuli were presented from 1 of 4 loudspeakers located at either 0°, +45°, -90°, and -135° or 0°, -45°, +90°, and +135°. Cafeteria noise was presented from separate loudspeakers surrounding the listener. Participants repeated sentences (sentence recognition) and also answered questions after listening to an unfamiliar story (comprehension). They were tested unaided, with a RM system (microphone near the front loudspeaker), and with a CROS system (ear-level microphone on the ear with simulated hearing loss).ResultsRelative to unaided listening, both rerouting systems reduced sentence recognition performance for most signals originating near the ear with normal hearing (monaural direct loudspeakers). Only the RM system improved speech recognition for midline signals, which were near the RM. Only the CROS system significantly improved speech recognition for signals originating near the ear with simulated hearing loss (monaural indirect loudspeakers). Although the benefits were generally small (approximately 6.5 percentage points), the CROS system also improved comprehension scores, which reflect overall listening across all four loudspeakers. Conversely, the RM system did not improve comprehension scores relative to unaided listening.ConclusionsBenefits of the CROS system in this study were small, specific to situations where speech is directed toward the ear with hearing loss, and relative only to a RM system utilizing one microphone. Although future study is warranted to evaluate the generalizability of the findings, the data demonstrate both CROS and RM systems are nonsurgical interventions that have the potential to improve speech recognition and comprehension for children with limited useable unilateral hearing in dynamic, noisy classroom situations.
Project description:A definitive study on the prevalence of adult unilateral hearing loss and hearing aid rehabilitation is lacking in Korea. The purpose of our study was to investigate the prevalence of adult unilateral hearing loss and the factors associated with hearing aid use in patients with unilateral hearing loss in South Korea. We obtained data from 2009 to 2012 from the Korea National Health and Nutrition Examination Surveys (KNHANES), a cross-sectional, nationwide and population-based survey in the Republic of Korea. We analyzed the prevalence and associated factors of unilateral hearing loss and hearing aid adoption by univariable and multivariable analysis. Unilateral hearing loss was defined as pure tone average ≥ 41 dB in the worse hearing ear, and < 41 dB in the other ear assessed at 0.5, 1.0, 2.0, and 3.0 kHz. From 2009 to 2012, 33,252 individuals participated in the KNHANES. Among them, the number of patients with unilateral hearing loss was 1632 (5.55%) and the prevalence of hearing aid adoption in unilateral hearing loss was 1.56%. We also compared the factors between hearing aid users and non-users. Occupational status (OR 3.759, 95% CI 1.443-9.804), the hearing threshold in the better ear (OR 1.088, 95% CI 1.029-1.151), and hearing threshold in the worse ear (OR 1.031, 1.005-1.058) were found to affect the adoption of hearing aids. The prevalence of noise exposure at work in hearing aid users was significantly lower than the prevalence of noise exposure at work in those with no hearing aid. The prevalence of hearing aid use in patients with unilateral hearing loss in Korea is very low compared to other countries. Public health education is needed to increase public awareness of unilateral hearing loss, hearing aid adoption and its continued usage. Auditory rehabilitation should be actively recommended to patients with unilateral hearing loss.
Project description:Longitudinal electronic health records from a large sample of new hearing-aid (HA) recipients in the US Veterans Affairs healthcare system were used to evaluate associations of fitting laterality with long-term HA use persistence as measured by battery order records, as well as with short-term HA use and satisfaction as assessed using the International Outcome Inventory for Hearing Aids (IOI-HA), completed within 180 days of HA fitting. The large size of our dataset allowed us to address two aspects of fitting laterality that have not received much attention, namely the degree of hearing asymmetry and the question of which ear to fit if fitting unilaterally. The key findings were that long-term HA use persistence was considerably lower for unilateral fittings for symmetric hearing loss (HL) and for unilateral worse-ear fittings for asymmetric HL, as compared to bilateral and unilateral better-ear fittings. In contrast, no differences across laterality categories were observed for short-term self-reported HA usage. Total IOI-HA score was poorer for unilateral fittings of symmetric HL and for unilateral better-ear fittings compared to bilateral for asymmetric HL. We thus conclude that bilateral fittings yield the best short- and long-term outcomes, and while unilateral and bilateral fittings can result in similar outcomes on some measures, we did not identify any HL configuration for which a bilateral fitting would lead to poorer outcomes. However, if a single HA is to be fitted, then our results indicate that a better-ear fitting has a higher probability of long-term HA use persistence than a worse-ear fitting.
Project description:Hearing with a cochlear implant (CI) is limited compared to natural hearing. Although CI users may develop compensatory strategies, it is currently unknown whether these extend from auditory to visual functions, and whether compensatory strategies vary between different CI user groups. To better understand the experience-dependent contributions to multisensory plasticity in audiovisual speech perception, the current event-related potential (ERP) study presented syllables in auditory, visual, and audiovisual conditions to CI users with unilateral or bilateral hearing loss, as well as to normal-hearing (NH) controls. Behavioural results revealed shorter audiovisual response times compared to unisensory conditions for all groups. Multisensory integration was confirmed by electrical neuroimaging, including topographic and ERP source analysis, showing a visual modulation of the auditory-cortex response at N1 and P2 latency. However, CI users with bilateral hearing loss showed a distinct pattern of N1 topography, indicating a stronger visual impact on auditory speech processing compared to CI users with unilateral hearing loss and NH listeners. Furthermore, both CI user groups showed a delayed auditory-cortex activation and an additional recruitment of the visual cortex, and a better lip-reading ability compared to NH listeners. In sum, these results extend previous findings by showing distinct multisensory processes not only between NH listeners and CI users in general, but even between CI users with unilateral and bilateral hearing loss. However, the comparably enhanced lip-reading ability and visual-cortex activation in both CI user groups suggest that these visual improvements are evident regardless of the hearing status of the contralateral ear.
Project description:In patients with bilateral asymmetrical hearing loss (AHL), where only one hearing aid is available, it is difficult to decide which ear to amplify. The aim of this study was to evaluate the outcomes of hearing aid use for AHL patients fitted with a hearing aid in their worse ear only. One-hundred-two adults with asymmetrical-mixed or sensorineural hearing loss were retrospectively included. AHL was classified into three subgroups: unilateral hearing loss (UHL) and AHL type 1 (AHL1) and type 2 (AHL2). The main outcome measures were (1) the time spent wearing a hearing aid, (2) the hearing in a noise test (HINT), (3) the sound localization test and (4) the Korean version of the International Outcome Inventory for Hearing Aids (IOI-HA). The 1 kHz-hearing threshold of the better ear was significantly better in the successful users than in the intermittent users for UHL. Younger age was associated with significantly better outcomes than older for AHL1 and AHL2. Among the etiologies of AHL, sudden hearing loss was associated with significantly better outcomes of hearing aid use for AHL, UHL and AHL1 patients. In this study, the success rate and usage rates were 43.1% and 67.6% in AHL patients wearing a hearing aid in the worse ear. This study identified the hearing threshold of 1 kHz from the better ear, age and etiology of sudden hearing loss as audiometric and non-audiometric factors that affected the outcomes of hearing aid use.
Project description:ObjectivesToday, approximately 70 to 80% of hearing aid fittings are made with silicone instant ear tips rather than custom earmolds. Nevertheless, little is known about the impact of instant ear tips on the acoustic coupling between the hearing aid receiver and the individual ear canal, even though it can have a major impact on the overall sound of the hearing aids. This study aimed to investigate the acoustic properties of different instant ear tip types and their across-subject variability, the within-subject reliability of those properties, and the influence of the users' level of experience with ear-tip insertion on the acoustics. Furthermore, subjective ratings of occlusion produced by the ear tips were considered.DesignFive types of instant ear tips (Open, Tulip, Round [2-vent], Round [1-vent], Double Domes) provided by the hearing aid manufacturer Widex were considered in this study. Probe-microphone measurements were performed at the eardrums of 30 participants (60 ears). In the first experiment, the real ear occluded insertion gain and the vent effect (VE) were measured, and the listeners rated the subjective occlusion experienced with each ear tip. In the second experiment, the same measurements were repeated six times per participant. The within-subject variability of the acoustic ear tip properties was investigated as well as the impact of the degree of users' experience with ear tip insertion on the resulting real ear measurements.ResultsAll tested ear tips were, on average, acoustically transparent up to 1 kHz except Double Domes, which were only transparent up to 600 Hz. Distinct VE profiles were found for each ear tip type, but a large across-subject variability was observed for both real ear occluded insertion gain and VE. However, the within-subject reliability was high. The measured VE was highly correlated with the perceived occlusion. Finally, no significant effect of the level of experience in ear tip insertion on the acoustic properties of the ear tips was found, but the within-subject variability was larger in the less experienced group.ConclusionsThese results suggest that the acoustic properties of instant ear tips and their coupling to the individual ear canal impact the resulting hearing aid fitting and should be considered by the hearing care professionals and reflected in the fitting software. The high within-subject reliability indicates that the ear tip acoustics remain stable for the individual in daily use. Finally, real ear measurements should be considered an essential part of the hearing aid fitting process in clinical practice to ensure an optimal fit for the individual hearing aid user.
Project description:IntroductionUsing a probe-tube microphone to measure and adjust the real-ear performance of the hearing aid to match the prescription target is recommended and widely used in clinical practice. Hearing aid fitting software can approximately match the amplification characteristics of the hearing aid to the prescription without real-ear measurements (REMs), but using REM improves the match to the prescribed target. What is unclear is if the improved match results in a better patient-reported outcome. The primary objective of this review is to determine whether the use of REM improves patient-reported outcomes in adult hearing aid users.Methods and analysisThe review's methods are in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines. MEDLINE, EMBASE, PsycINFO, CINAHL, Web of Science and CENTRAL via Cochrane Library will be searched to identify relevant studies. The review's population of interest will include adults with any degree of sensorineural or mixed hearing loss who have been prescribed with acoustic hearing aids. The included studies should compare REM fitting to the initial fit provided by the manufacturer's fitting software. Hearing-specific health-related quality of life is the primary outcome but secondary outcomes include self-reported listening ability, speech recognition scores, generic health-related quality of life, hours of use, number of required follow-up sessions and adverse events. Randomised and non-randomised controlled trials will be included. The risk of bias in the included studies will be evaluated using Down and Black's checklist. The quality of the overall evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations tool.Ethics and disseminationEthical approval will not be sought because this systematic review will only retrieve and analyse data from published studies. Review results will be published in a peer-reviewed journal and presented at relevant scientific conferences.Prospero registration numberCRD42020166074.