Cochlear Implantation Outcomes in Adults With Single-Sided Deafness: A Systematic Review and Meta-analysis.

OBJECTIVE: To assess spatial hearing, tinnitus, and quality-of-life outcomes in adults with single-sided deafness (SSD) who underwent cochlear implantation. DATABASES REVIEWED: PubMed, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched from January 2008 to September 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. METHODS: Studies reporting spatial hearing, tinnitus, and quality-of-life outcomes in adult cochlear implant (CI) recipients (≥18 yr old) with SSD were evaluated. Study characteristics, demographic data, spatial hearing (speech recognition in noise, sound source localization), tinnitus (severity, loudness), and quality-of-life outcomes were collected. RESULTS: From an initial search of 1,147 articles, 36 studies that evaluated CI use in 796 unique adults with SSD (51.3 ± 12.4 yr of age at time of implantation) were included. The mean duration of deafness was 6.2 ± 9.6 years. There was evidence of improvement for speech recognition in noise using different target-to-masker spatial configurations, with the largest benefit observed for target-to-masker configurations assessing head shadow (mean, 1.87-6.2 dB signal-to-noise ratio). Sound source localization, quantified as root-mean-squared error, improved with CI use (mean difference [MD], -25.3 degrees; 95% confidence interval [95% CI], -35.9 to -14.6 degrees; p < 0.001). Also, CI users reported a significant reduction in tinnitus severity as measured with the Tinnitus Handicap Inventory (MD, -29.97; 95% CI, -43.9 to -16.1; p < 0.001) and an improvement in spatial hearing abilities as measured with the Spatial, Speech, and Qualities of Hearing questionnaire (MD, 2.3; 95% CI, 1.7 to 2.8; p < 0.001). CONCLUSIONS: Cochlear implantation and CI use consistently offer improvements in speech recognition in noise, sound source localization, tinnitus, and perceived quality of life in adults with SSD.

Subjective Fatigue in Children With Unaided and Aided Unilateral Hearing Loss.

OBJECTIVES: Fatigue is frequently observed in children with chronic diseases and can affect the quality of life (QoL). However, research in children with unilateral hearing loss (UHL) is scarce. Subsequently, no studies investigated the effects of hearing aids on fatigue in children. This study investigates subjective fatigue and hearing-related QoL in children with UHL. Furthermore, it evaluates the influence of hearing aids, subject-specific factors, and respondent-type on subjective fatigue. STUDY DESIGN: A cross-sectional study was conducted from June 2020 until September 2020 at the department of otorhinolaryngology in a tertiary referral center. METHODS: The primary outcome was the difference in subjective fatigue and hearing-related QoL between children with unaided UHL, aided UHL, and normal hearing. Subjective fatigue and hearing-related QoL were measured using the Pediatric Quality of Life Inventory™ Multidimensional Fatigue Scale (PedsQL™-MFS) and Hearing Environments and Reflection on Quality of Life (HEAR-QL™) questionnaires. RESULTS: Along with 36 aided children with UHL, 34 unaided and 36 normal-hearing children were included. Child reports revealed significantly more cognitive fatigue in children with aided UHL than children with normal hearing (median difference 12.5, P = .013). Parents reported more fatigue in children with UHL compared to normal-hearing siblings. Especially children with aided UHL seemed at increased risk for fatigue. Children with UHL scored lower on hearing-related QoL than children with normal hearing. No apparent differences were found in fatigue and QoL between children with unaided and aided UHL. CONCLUSION: Children with unaided and even aided UHL seem to experience more subjective fatigue and lower hearing-related QoL than children with normal hearing. Prospective longitudinal studies are required to investigate the influence of hearing aids on fatigue and QoL in individual patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 2021 Laryngoscope, 133:189-198, 2023.

Are children with unilateral hearing loss more tired?

OBJECTIVE: To determine whether children with unilateral sensorineural hearing loss (USNHL) and unilateral conductive hearing loss (UCHL) have higher levels of fatigue than literature reported normal hearing (LRNH) children. METHODS: This was a cross-sectional survey utilizing the PedsQL™ Multidimensional Fatigue Scale administered to children with unilateral hearing loss (UHL) and their parents at two tertiary care academic medical centers and a nationwide microtia/atresia conference. The PedsQL™ Multidimensional Fatigue Scale was used to compare child and parental proxy reports of fatigue among USNHL, UCHL, and LRNH children. ANOVA and post-hoc Tukey Honest Significant Difference testing were used for statistical analysis. RESULTS: Of 69 children included in the study, 42 had UCHL (61%) and 27 (39%) had USNHL. Children with USNHL reported more total fatigue (mean 69.1, SD 19.3) than LRNH children (mean 80.5, SD 13.3; difference -11.4; 95% CI: -19.98 to -2.84) and children with UCHL (mean 78.0, SD 14.5; difference -8.95; 95% CI: -17.86 to 0.04). Children with UCHL reported similar levels of fatigue compared to LRNH children (difference -2.5; 95% CI: -9.95 to 5.03). Parents of children with USNHL reported greater levels of fatigue (mean 67.6, SD 22.6) in their children than parents of LRNH children (mean 89.6, SD 11.4; difference -22.0; 95% CI: -29.8 to -14.3) and parents of children with UCHL (mean 76.2, SD 17.3; difference -8.6; 95% CI: -17.5 to 0.21). Parents of children with UCHL also report higher levels of fatigue than parents of LRNH children (difference -13.4; 95% CI: -19.98 to -6.84). CONCLUSIONS: Children with USNHL reported greater levels of fatigue than LRNH children and children with UCHL. Results implicate cognitive load as an important consideration in children with hearing loss. The measurement of fatigue may be a useful indicator to determine the benefit of intervention (e.g., amplification) for these children.

Rehabilitation for unilateral deafness - Narrative review comparing a novel bone conduction solution with existing options.

Patients with single sided deafness (SSD) struggle with sound localization and speech in noise. Existing treatment options include contralateral routing of signal (CROS) systems, percutaneous bone conduction hearing devices (BCHDs), passive transcutaneous BCHDs, active BCHDs, and cochlear implants. Implanted devices provide benefits in speech in noise compared to CROS devices. Percutaneous BCHDs transmit sound efficiently but have aesthetic drawbacks and skin complications. Scalp attenuation impacts passive transcutaneous BCHD performance. Active BCHDs overcome these issues and provide benefits for speech in noise. Cochlear implantation is the only existing option that restores binaural input but introduces electrical rather than acoustic stimuli to the deaf ear. Active BCHDs have been designed to maintain efficient sound transmission and avoid chronic skin irritation and cosmetic concerns that may occur with percutaneous BCHDs. Cochlear implantation may be a superior option for recently deafened SSD patients, though this requires further study. The duration of deafness, patient age and comorbidities, and a shared decision-making model among patients, surgeons, and audiologists should be considered in device selection. The aim of this manuscript is to review available devices, discuss surgical considerations for implantable devices, review available published results for speech in noise and sound quality with each device, and provide an overview to guide shared decision making for patients and providers. This review consolidates available literature and reviews experience with a newer active transcutaneous active BCHD available for use in the SSD population.

Quality of life of children treated for unilateral hearing loss: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the treatments' consequences for unilateral hearing loss in children. DESIGN: Systematic review and meta-analysis (CRD42018109417). The MEDLINE, CENTRAL, ISRCTN and ClinicalTrials databases were searched between September 2018 and May 2019. Articles were screened and data were collected independently by two authors following the Cochrane and Preferred Reporting Items for Systematic review and Meta-Analysis guidelines. The risk of bias was evaluated using the Cochrane tool, the Newcastle-Ottawa Scale, the National Institute of Health, USA tool and considering the risk of confounding. In the studies with the lowest risk of bias, a meta-analysis was conducted. INTERVENTIONS: Validated hearing rehabilitation devices. PATIENTS: 6-15 years old children with moderate to profound unilateral hearing loss. MAIN OUTCOME MEASURES: The primary study outcome was children's quality of life. Academic performances were studied as an additional outcome. RESULTS: 731 unique articles were identified from the primary search. Of these, 18 articles met the Population, Intervention, Control, Outcomes and Study design selection criteria. In the eight studies with the lowest risk of bias, two meta-analysis were conducted. There was not enough data on academic results to conduct a meta-analysis. In 73 children included in a fixed effect meta-analysis (two studies), no effect of treatment could be shown (g=-0.20, p=0.39). In 61 children included in a random-effect meta-analysis (six studies), a strong positive effect of hearing treatment on quality of life was demonstrated (g=1.32, p<0.05). CONCLUSIONS: The treatment of unilateral hearing loss seems to improve children's quality of life. Further research is needed to identify the most effective treatment and its corresponding indications.

The Influence of Forced Social Isolation on the Auditory Ecology and Psychosocial Functions of Listeners With Cochlear Implants During COVID-19 Mitigation Efforts.

OBJECTIVES: The impact of social distancing on communication and psychosocial variables among individuals with hearing impairment during COVID-19 pandemic. It was our concern that patients who already found themselves socially isolated (Wie et al. 2010) as a result of their hearing loss would be perhaps more susceptible to changes in their communication habits resulting in further social isolation, anxiety, and depression. We wanted to better understand how forced social isolation (as part of COVID-19 mitigation) effected a group of individuals with hearing impairment from an auditory ecology and psychosocial perspective. We hypothesized that the listening environments would be different as a result of social isolation when comparing subject's responses regarding activities and participation before COVID-19 and during the COVID-19 pandemic. This change would lead to an increase in experienced and perceived social isolation, anxiety, and depression. DESIGN: A total of 48 adults with at least 12 months of cochlear implant (CI) experience reported their listening contexts and experiences pre-COVID and during-COVID using Ecological Momentary Assessment (EMA; methodology collecting a respondent's self-reports in their natural environments) through a smartphone-based app, and six paper and pencil questionnaires. The Smartphone app and paper-pencil questionnaires address topics related to their listening environment, social isolation, depression, anxiety, lifestyle and demand, loneliness, and satisfaction with amplification. Data from these two-time points were compared to better understand the effects of social distancing on the CI recipients' communication abilities. RESULTS: EMA demonstrated that during-COVID CI recipients were more likely to stay home or be outdoors. CI recipients reported that they were less likely to stay indoors outside of their home relative to the pre-COVID condition. Social distancing also had a significant effect on the overall signal-to-noise ratio of the environments indicating that the listening environments had better signal-to-noise ratios. CI recipients also reported better speech understanding, less listening effort, less activity limitation due to hearing loss, less social isolation due to hearing loss, and less anxiety due to hearing loss. Retrospective questionnaires indicated that social distancing had a significant effect on the social network size, participant's personal image of themselves, and overall loneliness. CONCLUSIONS: Overall, EMA provided us with a glimpse of the effect that forced social isolation has had on the listening environments and psychosocial perspectives of a select number of CI listeners. CI participants in this study reported that they were spending more time at home in a quieter environments during-COVID. Contrary to our hypothesis, CI recipients overall felt less socially isolated and reported less anxiety resulting from their hearing difficulties during-COVID in comparison to pre-COVID. This, perhaps, implies that having a more controlled environment with fewer speakers provided a more relaxing listening experience.

Effects of SoundBite Bone Conduction Hearing Aids on Speech Recognition and Quality of Life in Patients with Single-Sided Deafness.

Objectives: To analyze the clinical application of SoundBite bone conduction hearing aids by assessing the improvement of speech recognition and the scores of the benefit scale questionnaire for patients with single-sided deafness (SSD). Design: Nine patients aged 24 to 61 years with SSD for more than 3 months were enrolled in this study. The patients could understand and repeat Mandarin and have good compliance with the study. The measurements were evaluated before and after one month of wearing hearing aids using the pure tone audiometry threshold, speech recognition in quiet and in noise, and the Glasgow Benefit Inventory (GBI) benefit scale score. Results: Pure tone audiometry results showed that the average hearing threshold of good ears and bad ears was 11.4 ± 2.6 dB HL and 89.9 ± 6.4 dB HL, respectively. The average hearing threshold of bad ears after wearing hearing aids was 23.5 ± 9.0 dB HL. Statistical analysis showed that the hearing improvement for the bad ears after wearing hearing aids was significant. The speech audiometry results showed that the disyllable word recognition score of the bad ears in quiet increased significantly at 50 dB SPL by 40 ± 12 percentage points and at 65 dB SPL by 71 ± 15 percentage points. As for the speech recognition in noise, when the signal sound came from the bad ear side and the noise from the good ear side (SSSDNAH), the speech recognition score (SRS) significantly increased by 17 ± 6 and 9 ± 4 at a signal-to-noise ratio (SNR) of -2 dB and -5 dB, respectively, after wearing the hearing aids. When the signal sound came from the front of the patient and the noise from the bad ear side (S0NSSD), the SRS scores were reduced by 5 ± 5 and 7 ± 5 percentage points at SNR equal to -2 dB and -5 dB, which was significantly different from that before wearing the hearing aids. When the signal and noise both came from the front of the patients (S0N0), the SRS was not significantly increased by 5 ± 4 percentage points at SNR equal to -2 dB compared to before wearing hearing aids. However, the SRS was significantly increased by 5 ± 2 percentage points at SNR equal to -5 dB compared to before wearing hearing aids. The average total GBI score was 31 ± 12 for the nine patients, with an average score of 32 ± 10, 31 ± 8, and 30 ± 7 for general conditions, social support, and physical health, respectively. The results of the questionnaires showed that patients' quality of life was improved after wearing SoundBite bone conduction hearing aids. Conclusions: SoundBite bone conduction hearing aids are a good choice for patients with SSD, as it could improve the speech recognition ability of patients both in a quiet and noisy environment and improves the quality of life after wearing hearing aids.

What can we learn from adult cochlear implant recipients with single-sided deafness who became elective non-users?

Objective: This retrospective study investigates the incidence of elective cochlear implant (CI) non-use amongst a cohort of adult CI recipients with single-sided deafness (SSD), identifies the causes that led to non-use, and assesses how non-use could be prevented. Methods: All adults with SSD who received a CI between 2008 and 2018 and who became elective CI non-users were included. Elective non-users were defined as CI recipients who decided to stop using their CI or, if explantation was necessary, refused reimplantation. Results: 5/114 (4.4%) adults with SSD who received a CI became elective non-users. The 5 non-users were a mean 44.2 years old (range 33-70 years) at implantation, had a mean duration of deafness of 7.1 years (range 0.5-20 years) at implantation, and used their CI for a mean 11.5 months (range 1.5-60 months) before (fully) discontinuing use. The primary cause of elective non-use was postoperative discouragement due to unrealistic expectations (4 participants) regarding sound perception with the CI or about the greater than expected level of commitment necessary for rehabilitation. Conclusions: Elective non-use among adult CI recipients with single-sided deafness was very rare and could be further prevented by comprehensive counselling to ensure that candidates have realistic expectations about the rehabilitation requirements and the outcomes with the CI.

Multifactorial positive influence of cochlear implantation on patients with single-sided deafness.

OBJECTIVES: Single-sided deafness (SSD) is an extreme case with profound unilateral hearing loss in the poorer ear and regular hearing in the other ear. The aim of this study is to investigate the impairment in the daily life of SSD patients and the influence of cochlear implants (CI) on their health-related quality of life (HRQoL), the impact on existing tinnitus distress and psychological comorbidities, and audiometric parameters. METHODS: In total, 21 patients (8 male and 13 female) were included, and the Charité Test Battery was applied for all patients. Data on HRQoL were collected with the Nijmegen Cochlear Implant Questionnaire and the Medical Outcome Study Short Form 36 (SF-36) Survey. Tinnitus distress was assessed with the Tinnitus Questionnaire (TQ). Data with regard to psychological comorbidities were collected using four validated questionnaires. Speech perception was assessed with the Freiburg Monosyllable Test (FMS), the Oldenburg Sentence Test (OLSA), and the Oldenburg Inventory (OI). RESULTS: HRQoL improved in the subdomain social interactions. Tinnitus distress dropped significantly 6 months postoperatively. SSD patients preoperatively showed elevated levels of stress, depressive symptoms, and anxiety. Postoperatively, these psychological symptoms improved with regard to stress, tension, and demands. The audiometry tools revealed a significant improvement in directional hearing (OI), speech perception in silence, and in the speech intelligibility threshold (OLSA). CONCLUSION: There was an improvement in HRQoL and a reduction of tinnitus and cognitive distress. The preoperatively elevated stress level decreased significantly, and psychological comorbidities such as depressive symptoms and anxiety all improved postimplantation. LEVEL OF EVIDENCE: II-2 Laryngoscope, 130:500-506, 2020.

Contribution of spectral pinna cues for sound localization in children with congenital unilateral conductive hearing loss after hearing rehabilitation.

Congenital unilateral conductive hearing loss (UCHL) jeopardizes directional hearing and speech perception in noisy conditions. Potentially, children with congenital UCHL can benefit from fitting a hearing device, such as a bone-conduction device (BCD). However, the literature reports limited benefit from fitting a BCD, and often, surprisingly, relatively good sound localization in the unaided condition is reported. In this study, we hypothesized that the limited benefit with a BCD is related to (i) insufficient access to binaural cues and (ii) relying on monaural spectral pinna cues for sound localization in the horizontal plane. Directional hearing was tested in seventeen children with congenital UCHL (age 6-19) using a percutaneous BCD. Additionally, a mold was placed in the pinna of the normal-hearing ear to diminish direction-dependent spectral pinna cues. Relatively good localization in azimuth was found in the unaided hearing condition in the majority of the children. Sound localization improved when listening with a BCD, and no correlation between age of implantation and aided localization performance was found. When the mold was inserted, the unaided and aided localization abilities of most children deteriorated. Interestingly, in the children with poor localization performance in the unaided condition, sound localization improved significantly with the BCD, and was hardly affected by molding the pinna of the normal-hearing ear. These observations indicate that the majority of these children rely on spectral pinna cues to localize sounds, independent of listening with or without their device. In conclusion, an important reason for the limited benefit of BCD fitting in children with congenital UCHL might be ascribed to an effective coping strategy (use of spectral pinna cues) that still plays a dominant role after BCD fitting.

Cochlear implant in patients with single sided deafness: hearing results and communicative benefits.

Objective: Evaluate auditory results and communicative benefits in adult patients with single-sided deafness (SSD) treated with cochlear implantation.Study Design: Observational descriptive case series.Setting: Hospital Universitario Fundación Santa Fe de Bogotá.Patients: Ten patients with profound post-lingual SSD were treated with cochlear implantation between January 2011 and March 2016. Two patients were excluded because of incomplete follow-up.Interventions: Medical records included demographic information, pre and post-operative audiometric results, and binaural and monoaural speech discrimination tests in three sound-in-noise configurationswith the cochlear implant turned on and off, respectively. Subjective improvement was evaluated using the Abbreviated Profile of Hearing Aid Benefit (APHAB) and Speech, Spatial, and Qualities of Hearing Scale (SSQ-B).Main Outcome Measures: Pre and post-operative audiometric and speech discrimination results, post-operative binaural and monoaural speech discrimination in noise results, and APHAB and SSQ-B questionnaire results.Results: Significant improvement in speech discrimination in a noisy environment was found when the noise and signal were presented from the front, and when the signal was presented to the implanted ear and the noise to the healthy ear. SSQ-B questionnaire showed improvement in all subscales, while APHAB showed improvement in all subscales except sound aversion.Conclusion: Patients with SSD showed improvement regarding communication skills and sound discrimination in a noisy environment.

Quality of Life in Children with Sensorineural Hearing Loss.

OBJECTIVE: To assess quality of life (QOL) in pediatric patients with sensorineural hearing loss (SNHL) with the Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0) and the Hearing Environments and Reflection on Quality of Life 26 (HEAR-QL-26) and HEAR-QL-28 surveys. STUDY DESIGN: Prospective longitudinal study. SETTING: Tertiary care center. SUBJECTS AND METHODS: Surveys were administered to patients with SNHL (ages 2-18 years) from July 2016 to December 2018 at a multidisciplinary hearing loss clinic. Patients aged >7 years completed the HEAR-QL-26, HEAR-QL-28, and PedsQL 4.0 self-report tool, while parents completed the PedsQL 4.0 parent proxy report for children aged ≤7 years. Previously published data from children with normal hearing were used for controls. The independent t test was used for analysis. RESULTS: In our cohort of 100 patients, the mean age was 7.7 years (SD, 4.5): 62 participants had bilateral SNHL; 63 had mild to moderate SNHL; and 37 had severe to profound SNHL. Sixty-eight patients used a hearing device. Mean (SD) total survey scores for the PedsQL 4.0 (ages 2-7 and 8-18 years), HEAR-QL-26 (ages 7-12 years), and HEAR-QL-28 (ages 13-18 years) were 83.9 (14.0), 79.2 (11.1), 81.2 (9.8), and 77.5 (11.3), respectively. Mean QOL scores for patients with SNHL were significantly lower than those for controls on the basis of previously published normative data (P < .0001). There was no significant difference in QOL between children with unilateral and bilateral SNHL or between children with SNHL who did and did not require a hearing device. Low statistical power due to small subgroup sizes limited our analysis. CONCLUSION: It is feasible to collect QOL data from children with SNHL in a hearing loss clinic. Children with SNHL had significantly lower scores on validated QOL instruments when compared with peers with normal hearing.

Deaf in one ear: Communication and social challenges of patients with single-sided deafness post-diagnosis.

OBJECTIVE: To understand the communication and social challenges that individuals with SSD face post diagnosis. METHODS: Fifty-two single-sided deaf patients from all over the world participated in semi-structured interviews. Interviews were digitally recorded, transcribed verbatim, and coded using a thematic analysis approach. RESULTS: Patients with single sided deafness identified challenges including: increased reliance on family members, decreased sense of autonomy, communication quality changes with family members, information discrepancy across family members and various emotional responses, conflicting information from interactions with multiple medical professionals, and lack of knowledge regarding what to anticipate post diagnosis. CONCLUSION: This study provides insights into patients' perspectives around single-sided deafness and its challenges, and the various health care approaches (e.g., patient- and family-centered care, third party disability, patient navigation) that could be implemented post diagnosis to decrease negative experiences and outcomes associated with SSD. PRACTICAL IMPLICATIONS: This study has practical implications for improving our understanding of what single-sided deaf patients need and for health professionals to offer better care to current and future populations impacted by single-sided deafness.

Auditory, Social, and Behavioral Skills of Children With Unilateral/Mild Hearing Loss.

This study explored the impact of mild bilateral or unilateral hearing loss on auditory, social, and behavior skills in early school-aged children. Thirty-two children (aged 5-9 years) were evaluated with parent and teacher questionnaires. Most outcomes were within the range of expected scores. However, functional auditory skills were below published results for children with typical hearing. On the social skills scale, about 21.4% (parent-reported) and 20.0% (teacher-reported) of children were below one standard deviation (SD) of the normative mean (i.e., a standard score below 85). On the parent-reported behavior test, over a quarter of children scored beyond 1 SD on some subscales. Laterality of hearing loss had no effect on outcomes (p > .05). Agreement between parents and teachers varied from poor (intraclass correlation coefficient [ICC]: .162) to moderate (ICC: .448). Results indicate that these children are functioning in most areas like their peers with typical hearing. Additional research on this population of children who may benefit from early identification and amplification is warranted.

Low-Frequency Pitch Perception in Cochlear Implant Recipients With Normal Hearing in the Contralateral Ear.

Purpose Three experiments were carried out to evaluate the low-frequency pitch perception of adults with unilateral hearing loss who received a cochlear implant (CI). Method Participants were recruited from a cohort of CI users with unilateral hearing loss and normal hearing in the contralateral ear. First, low-frequency pitch perception was assessed for the 5 most apical electrodes at 1, 3, 6, and 12 months after CI activation using an adaptive pitch-matching task. Participants listened with a coding strategy that presents low-frequency temporal fine structure (TFS) and compared the pitch to that of an acoustic target presented to the normal hearing ear. Next, participants listened with an envelope-only, continuous interleaved sampling strategy. Pitch perception was compared between coding strategies to assess the influence of TFS cues on low-frequency pitch perception. Finally, participants completed a vocal pitch-matching task to corroborate the results obtained with the adaptive pitch-matching task. Results Pitch matches roughly corresponded to electrode center frequencies (CFs) in the CI map. Adaptive pitch matches exceeded the CF for the most apical electrode, an effect that was larger for continuous interleaved sampling than TFS. Vocal pitch matches were variable but correlated with the CF of the 3 most apical electrodes. There was no evidence that pitch matches changed between the 1- and 12-month intervals. Conclusions Relatively accurate and asymptotic pitch perception was observed at the 1-month interval, indicating either very rapid acclimatization or the provision of familiar place and rate cues. Early availability of appropriate pitch cues could have played a role in the early improvements in localization and masked speech recognition previously observed in this cohort. Supplemental Material https://doi.org/10.23641/asha.8862389.

Topological reorganization after partial auditory deprivation-a structural connectivity study in single-sided deafness.

Growing evidence shows that partial auditory deprivation leads to extensive neural functional plasticity, which occurs not only in the auditory cortex but also in other sensory regions and cognitive areas. However, studies in structural topological properties are still limited, especially those investigating the relationship between structural connectome alterations and auditory abilities. To clarify this, we investigated white matter structural connectivity changes and the relationship between connection strength and hearing abilities in individuals with long-term single-sided deafness (SSD), a common form of partial hearing deprivation, using diffusion tensor imaging and network-based analysis. The results showed globally improved connection efficiency, locally weakened visual networks, and strengthened fronto-parietal sub-networks in SSD compared to normal hearing controls. Furthermore, a strong positive correlation between hearing abilities (including speech recognition in noise and sound localization) and connection strength, mainly in the fronto-parietal areas, was found in SSD. Our study reveals alteration of the structural network connections in SSD, especially in cognitive related networks, which showed close correlation with hearing abilities. Our findings provide new insights into topological white matter reorganization of the brain after partial sensory deprivation.

Animal and human studies on developmental monaural hearing loss.

Asymmetric hearing has been the focus of many studies on brain plasticity in the past. Recently, the topic has gained clinical importance in cases with sequential cochlear implantation or in cases with deafness in one ear and preserved hearing in the other ear. Convergent evidence from animal experiments and from hearing impaired children suggest that asymmetric hearing during early development can reorganize the central auditory representation of the two ears with the consequence of a "stronger" representation of the better hearing ear with a "weaker" representation of the other, more poorly hearing, ear. These changes lead to a persistent aural preference for one ear, demonstrated by asymmetric speech comprehension when each ear is tested separately. Further, binaural integration is compromised as shown by reduced binaural fusion and reduced sensitivity for binaural cues. Finally, the data demonstrate a significant difference in cortical plasticity in response to juvenile monocular deprivation in the visual system and juvenile monaural deafness in the auditory system. The topic represents a unique example of translational research whereby mechanisms explored in animal models are combined with data from children to understand the clinical consequences of asymmetric hearing in early development.

EEG rhythms lateralization patterns in children with unilateral hearing loss are different from the patterns of normal hearing controls during speech-in-noise listening.

Unilateral hearing loss constitutes a field of growing interest in the scientific community. In fact, this kind of patients represent a unique and physiological way to investigate how neuroplasticity overcame unilateral deafferentation by implementing particular strategies that produce apparently next- to- normal hearing behavioural performances. This explains why such patients have been underinvestigated for a long time. Thanks to the availability of techniques able to study the cerebral activity underlying the mentioned behavioural outcomes, the aim of the present research was to elucidate whether different electroencephalographic (EEG) patterns occurred in unilateral hearing loss (UHL) children in comparison to normal hearing (NH) controls during speech-in-noise listening. Given the intrinsic lateralized nature of such patients, due to the unilateral side of hearing impairment, the experimental question was to assess whether this would reflect a different EEG pattern while performing a word in noise recognition task varying the direction of the noise source. Results showed a correlation between the period of deafness and the cortical activity asymmetry toward the hearing ear side in the frontal, parietal and occipital areas in all the experimental conditions. Concerning alpha and beta activity in the frontal and central areas highlighted that in the NH group, the lateralization was always left-sided during the Quiet condition, while it was right-sided in noise conditions; this evidence was not, however, detected also in the UHL group. In addition, focusing on the theta and alpha activity in the frontal areas (Broca area) during noise conditions, while the activity was always left-lateralized in the NH group, it was ipsilateral to the direction of the background noise in the UHL group, and of a weaker extent than in NH controls. Furthermore, in noise conditions, only the UHL group showed a higher theta activity in the temporal areas ipsilateral to the side where the background noise was directed to. Finally, in the case of bilateral noise (background noise and word signal both coming from the same two sources), the theta and alpha activity in the frontal areas (Broca area) was left-lateralized in the case of the NH group and lateralized towards the side of the better hearing ear in the case of the UHL group. Taken together, this evidence supports the establishment of a particular EEG pattern occurrence in UHL children taking place in the frontal (Broca area), temporal and parietal lobes, probably physiologically established in order to deal with different sound and noise source directions.

The impact of permanent early-onset unilateral hearing impairment in children - A systematic review.

BACKGROUND: Decision-making on treatment and (re)habilitation needs to be based on clinical expertise and scientific evidence. Research evidence for the impact of permanent unilateral hearing impairment (UHI) on children's development has been mixed and, in some of the reports, based on fairly small, heterogeneous samples. Additionally, treatment provided has been highly variable, ranging from no action taken or watchful waiting up to single-sided cochlear implantation. Published information about the effects of treatment has also been heterogeneous. Moreover, earlier reviews and meta-analyses published on the impact of UHI on children's development have generally focused on select areas of development. OBJECTIVES: This systematic review aimed to summarize the impact of children's congenital or early onset unilateral hearing impairment on listening and auditory skills, communication, speech and language development, cognitive development, educational achievements, psycho-social development, and quality of life. METHODS: Literature searches were performed to identify reports published from inception to February 16th, 2018 with the main electronic bibliographic databases in medicine, psychology, education, and speech and hearing sciences as the data sources. PubMed, CINALH, ERIC, LLBA, PsychINFO, and ISI Web of Science were searched for unilateral hearing impairment with its synonyms and consequences of congenital or early onset unilateral hearing impairment. Eligible were articles written in English, German, or Swedish on permanent unilateral hearing impairments that are congenital or with onset before three years of age. Hearing impairment had to be of at least a moderate degree with PTA ≥40 dB averaged over frequencies 0.5 to 2 or 0.5-4 kHz, hearing in the contralateral ear had to have PTA0.5-2 kHz or PTA0.5-4 kHz ≤ 20 dB, and consequences of unilateral hearing impairment needed to be reported in an unanimously defined population in at least one of the areas the review focused on. Four researchers independently screened 1618 abstracts and 566 full-text articles for evaluation of study eligibility. Eligible full-text articles were then reviewed to summarize the results and assess the quality of evidence. Additionally, data from 13 eligible case and multi-case studies, each having less than 10 participants, were extracted to summarize their results. Quality assessment of evidence was made adapting the Grades of Recommendations, Assessment, Development, and Evaluation (GRADE) process, and reporting of the results adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. RESULTS: Three articles with the quality of evidence graded as very-low to low, fulfilled the eligibility criteria set. Due to the heterogeneity of the articles, only a descriptive summary could be generated from the results. Unilateral hearing impairment was reported to have a negative impact on preverbal vocalization of infants and on sound localization and speech perception both in quiet and in noise. CONCLUSIONS: No high-quality studies of consequences of early-onset UHI in children were found. Inconsistency in assessing and reporting outcomes, the relatively small number of participants, low directness of evidence, and the potential risk of confounding factors in the reviewed studies prevented any definite conclusions. Further well-designed prospective research using larger samples is warranted on this topic.

A comparison between wireless CROS/BiCROS and soft-band BAHA for patients with unilateral hearing loss.

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.