Children with hearing loss are at increased risk of mental health conditions, including behavioural problems, but there is limited evidence about available mental health support.We aimed to map the evidence on mental health support for children and adolescents with hearing loss.Medline, Embase, PsycINFO and grey literature databases were searched until April 2021. Articles of any study design were eligible if they described an intervention supporting the mental health of children with hearing loss. No restrictions were placed on geography or publication date. Four reviewers independently screened results by title, abstract and full text. Study characteristics and outcome data were extracted, with results narratively synthesised.n = 22) were from high-income settings, with two-thirds  conducted in the USA. Less than half  of the articles adopted experimental research designs, and the majority of studies included small samples. The interventions presented were diverse, with the majority either therapy based  or skills training . Interventions included ice-skating, parent–child interaction therapy and resilience training. When measured, interventions demonstrated at least some evidence of effectiveness, although this was not always assessed with gold-standard methodology.From 5629 search results, 27 articles were included. A large majority of the studies (81%, The evidence is lacking in breadth, study quality and geographical spread. That said, what is available indicates a range of effective approaches to support the mental health of children with hearing loss. Additional research is needed to improve the breadth of evidence on mental health support for this population. Although hearing loss is more common among older adults, there are approximately 70 million children aged 0–15 with hearing loss across the world.1As of 2019, an estimated 20% of the global population (or 1.57 billion) have hearing loss, with 430 million having moderate-to-complete hearing loss.3 As a result, children with hearing loss are at increased risk of mental health conditions, such as anxiety and depression, with several studies demonstrating significantly higher prevalence of these conditions among children with hearing loss, compared with children without hearing loss.9 Evidence also shows that children with hearing loss are more likely to experience behavioural problems, including conduct and hyperactivity disorders.11 Half of mental health conditions start by the age of 14, yet these often go undetected and untreated.12 Among the general population, these conditions in childhood are associated with an increased risk of mental health concerns in adulthood, lower family income, lower probability of employment and lower probability of being married.14 Mental health conditions may also further disrupt ongoing child development, a challenge already present for children with hearing loss. Addressing mental health concerns, while promoting emotional, behavioural and psychological well-being, is imperative among children with hearing loss, in order to support a healthy childhood and reduce the risk of adverse experiences in adulthood.Children with hearing loss may experience language deprivation, impacting development, communication and socioemotional skills.15 However, there is limited synthesised evidence on interventions and types of support available for children with hearing loss that promote psychological, emotional and behavioural well-being, prevent mental health conditions and treat conditions that do arise. In 2019, a systematic review on the assessment and treatment of behavioural disorders in children with hearing loss found limited evidence of interventions to address behavioural problems.11 Evidence on interventions available for other mental health conditions is lacking. Information on the types of interventions applied, their characteristics and evidence of their effectiveness is needed to inform support programmes for children with hearing loss, whether these be in school, the community or delivered through the healthcare system.Youth mental health has received growing attention in recent years, as evidenced by the inclusion of 104 network meta-analyses and meta-analyses of randomised controlled trials (RCTs) on mental health interventions for children and adolescents in a recent umbrella review published in 2021.What are the characteristics of the available literature describing mental health support for children with hearing loss?What mental health interventions and support have been provided or evaluated for children with hearing loss?What evidence is available on the effectiveness of these interventions?What are the current gaps in the available evidence?This study aimed to systematically identify and map the evidence on mental health support for children and adolescents with hearing loss. We aimed to answer the following questions.16 The protocol for the review was registered on the Open Science Framework on 3 March 2020 (osf.io/8qdbz/). Ethics approval was obtained from the London School of Hygiene & Tropical Medicine Research Ethics Committee (Ref: 19144).With expected limited and heterogeneous data, we chose to conduct a scoping review, rather than an alternative evidence synthesis, in order to map the available evidence.18 We conducted the review across five stages: (a) identifying the research question; (b) identifying relevant studies; (c) study selection; (d) charting the data; and (e) collating and summarising the results.The scoping review has been conducted and reported according to the PRISMA Extension for Scoping Reviews (PRISMA-ScR) guideline and followed Arksey & O'Malley's framework for scoping reviews.Population: children aged 6–18, with diagnosed, proxy-report or self-reported hearing loss, of any severity. Included participants did not need to have a diagnosis of a mental disorder.Intervention: any initiative designed to improve the mental health and well-being of children with hearing loss, including interventions developed specifically for children with hearing loss or those adapted from interventions aimed at the general population. Interventions promoting developmental skills and protective factors, such as emotional regulation, resilience and self-esteem, were included if connection was made to child mental health and well-being. Interventions were also included if they addressed behavioural problems or disorders, such as hyperactivity or aggression. Activities could be focused on promotion, prevention or treatment, such as social interventions, skills development, targeted recreational activities and therapies. They could be delivered by any personnel in any setting. Interventions for parents, caregivers or other adults (for example teachers) were included if children with hearing loss were an intended beneficiary. Similarly, interventions were included if provided to a diverse group, as long as children with hearing loss were one of the beneficiaries.Comparator: studies with and without a control or comparison group were included. If a control or comparator is present, they must also be children with hearing loss of the same age, but who have not received the intervention.Outcomes: studies with or without assessment of any outcome were included. Where applicable, outcomes of interest included scores on mental health screening tools, acceptability/feasibility, cost-effectiveness and other reasonable data.Study design: published literature of any study design . Descriptive literature (i.e. without research methods applied) was included, if sufficient detail was provided on the intervention(s) available for children with hearing loss. Reviews and opinion pieces were excluded. There were no restrictions placed on geographic location, although articles needed to be in English. There were no limits placed on publication date. Grey literature, including dissertations and conference presentations, was included. Only articles with an available full text were included.https://doi.org/10.1192/bjo.2021.1045. Reference lists of each included study were examined in search of additional articles for inclusion.Articles were identified through a systematic search of Medline, Embase and PsycINFO. The search was initially conducted on 27 April 2020 and updated on 27 April 2021. An example of the search strategy is available in Supplementary File 1 available at The search for grey literature was conducted through OpenGrey and Google Scholar. Additionally, experts in this field were contacted for recommendations of known reports, and the websites of notable disability and hearing loss organisations were manually searched (Supplementary File 2).Authors N.S., T.B., D.J.M. and T.O.’F. independently screened all titles and abstracts against the eligibility criteria. Each record was screened by two reviewers. Eligible full-text articles were then independently reviewed by two reviewers. Although excluded from the final synthesis, systematic reviews and full-length books identified in the database search were manually screened by full-text, with included articles and book chapters selected for full-text screen, if relevant. Records identified from the reference lists of included articles were also filtered into the full-text screening. Discrepancies at any stage were discussed between the two reviewers, with a third and fourth reviewer consulted if needed. This review process was conducted using Covidence software.Publication details: author, year of publication, title, country, aims/objectives, study design.Characteristics of mental health support: type , intended outcome, setting, delivery agent, intervention components.Outcomes: type , measurement tools, findings .N.S. extracted the data for each study, using a custom form, developed in Excel. This extraction form was first piloted on three included articles, with amendments made as necessary. T.B., D.J.M. and T.O.’F. each independently reviewed one-third of data extracted. Discrepancies were discussed and resolved with N.S., with support from a third reviewer if needed. Data extracted included:19For an assessment of risk of bias, we used the critical appraisal tools from the Joanna Briggs Institute (JBI). There are various tools provided by JBI, designed for use with different designs, such as case report or RCT. Each tool can be used to determine the extent to which a study has addressed the possibility of bias in its design, conduct and analysis, via a series of relevant questions and standardised responses.Low risk: all or almost all of the criteria were fulfilled, and those that were not fulfilled were thought unlikely to alter the conclusions.Medium risk: some of the criteria were fulfilled, and those not fulfilled were thought unlikely to alter the conclusions of the study.High risk: few or no checklist criteria were fulfilled, and the conclusions of the study were thought likely to alter if these had been met.Studies were assessed by N.S., with scores reviewed by S.P. Based on the assessment against a JBI checklist, each study was rated as having high, medium or low risk of bias.Under the umbrella of mental health, the focus of this review, we have grouped articles by interventions that address psychological well-being and behavioural problems. Psychological well-being, in this instance, refers broadly to emotional well-being and mental health, and includes diagnosis or symptoms of mental health conditions, as well as related domains, such as resilience and self-esteem. Behavioural problems include disorders and concerns relating to disruptive and challenging behaviours, such as aggression, impulsivity and defiance. Specific behavioural disorders include attention-deficit hyperactivity disorder or oppositional defiant disorder.Under these two subheadings, we grouped articles by intervention type. Findings have been summarised narratively, with the focus on the characteristics of the interventions. Information on effectiveness has been narratively presented, where this information was available.When data presented in an article is disaggregated by age, with participants older or younger than the inclusion criteria included, only that attributable to children within the age range of 6–18 years was included in the synthesis.n = 3), records identified via the reference lists of included articles (n = 2) and the grey literature (n = 1). From 136 full texts assessed, 27 articles were included in the synthesis.46The database search generated 5629 results, from which 1253 duplicates were removed. In total, 4376 records were screened by title and abstract, from which 4245 were excluded based on the criteria above . There wOf the 27 included articles, 18 (67%) come from North America, and specifically the USA . Of the Eighteen (67%) provide information on support focused on psychological well-being, and related domains. Of these, four (15%) targeted protective psychological factors (such as resilience and emotion management), one (4%) social anxiety disorder, one (4%) substance misuse disorder and one (4%) obsessive–compulsive disorder. Fourteen (52%) of the 27 included articles focused support on behavioural problems, such as conduct disorder. Some articles focused on both psychological well-being and behavioural problems and the percentages presented therefore total greater than 100%.Twenty (74%) of the interventions included treatment options, 17 (63%) promotion activities and 7 (26%) prevention techniques. Eight (30%) interventions were therapeutic in nature, nine (33%) were a structured training programme, two (7%) based on physical exercise, and one (4%) medical. Seven (26%) others were intervention packages, comprised of multiple single interventions.Eighteen (67%) described activities delivered in schools, nine (33%) of which were special schools, three (11%) special education classrooms in a mainstream school and one (4%) a mainstream school. Four (15%) were conducted in residential settings, with schooling on site. Six (22%) were conducted in healthcare facilities, one (4%) a community setting, and two (7%) artificial/research settings. One (4%) study did not provide information on the setting.Nine (33%) of the included articles presented a case report or case series, six (22%) conducted randomised controlled trials, five (19%) used quasi-experimental methods (of which two were pilot studies) and one (4%) qualitative. Six (22%) of the articles described an intervention or support structure, without any research methods applied. One-third (33%) of articles included a sample size of less than ten participants, with only two studies (7%) including more than 100 participants.Summarising the ages and degree of hearing loss among participants included presented a challenge. Studies provided various classifications on the severity of hearing loss, and we have converted these under the same terms in The six (22%) articles that describe  an intervention were not included in the quality assessment. Of the 21 remaining, 7 (33%) were rated as having a low risk of bias, 10 (48%) medium and 4 (19%) high. Potential sources of bias among those rated to have a medium or high risk, included: inappropriate statistical analysis, including the absence of statistical power or sample size calculations in RCTs; no clinical information provided for participants in a case series; and unsuitable measurement of outcomes, including collection time points and screening method.As seen in Supplementary Table 1, 17 articles targeted psychological well-being and related factors (for example resilience).44 Examples included peer-support groups and therapeutic play. Four (24%) provided structured training and skills-based programmes, including group assertiveness training for social anxiety disorder.36 Two (12%) were focused on physical exercise and related activities, including ice-skating and dance lessons.30 One (6%) study investigated the impact of hearing aids on psychological well-being.38Five (29%) of these focused on forms of counselling, psychotherapy or group support.46 These were typically delivered in healthcare or residential settings. Individual interventions described in the packages were typical of those provided in mental health programmes for the general population, and included cognitive–behavioural therapy, medication, art therapy and peer-support groups.The remaining five (29%) articles provided information on intervention ‘packages’ that included more than one intervention approach.Fourteen articles provided support for behavioural problems. In four articles, the intervention or support provided addressed both psychological well-being and behavioural problems.44 Three (21%) provided parents with training, and typically included skills-building exercises, using role-play and similar techniques.41 Three (21%) focused training efforts on children.35 For example, the PATHS (Promoting Alternative Thinking Strategies) curriculum, which includes daily activities at school, delivered by teachers.34 One (7%) supported physical activity, in this instance, ice-skating.30 A further two (14%) articles described a support package including various activities.27 This included Walden House, a residential programme for children with hearing loss and behavioural problems, providing problem-solving skills, family therapy and role-play exercises.27Five of the 14 (36%) provided counselling or variations of psychotherapy, including video-counselling.Twenty three of the 27 articles provided information on the theory or evidence used to develop the intervention. The remaining four articles provided descriptions of logic-based arguments for the intervention model, without substantial information on evidence or theory. Of the 23 articles providing this information, 12 (52%) provided evidence of previous use or effectiveness of the intervention among children without disabilities or hearing loss, four provided (17%) evidence of its use with children with and without hearing loss, and four (17%) articles provided evidence of the intervention among children with hearing loss only. Four (17%) based the intervention on theories developed for children without hearing loss, such as the ABCD (Affective-Behaviour-Cognitive-Dynamic) model of child development.Of the 27 articles, 16 described specific considerations and adaptations made to the intervention to accommodate the needs of children with hearing loss, particularly when the support provided was initially developed for the general population.Of these, 13 (81%) described considerations of communication methods and needs, such as reading ability. Nine (56%) used sign language or provided sign language interpretation. Three (19%) made adaptations to the physical environment in which the intervention was delivered. For instance, seating groups in a circle to maximise visual contact, or providing pictures and posters to facilitate understanding. Three (19%) adapted the core structure, components, tools and methods of established interventions. For example, established programmes for the general population, such as D.A.R.E. and the PATHS curriculum were adapted and prepared with support from hearing loss specialists.In total, 19 articles provided information on the effectiveness of the intervention or programme.Eleven of these presented outcomes with regards to psychological well-being, with all but one finding some evidence of a positive impact of the intervention. Specifically, three (27%) provided evidence on the effectiveness of training programmes for children with hearing loss, including resilience training. One of these, targeting social anxiety disorder, reported no significant differences in symptomology between intervention and control groups in children with profound hearing loss, but did see a difference for those with moderate hearing loss. Two (18%) demonstrated the positive effect of physical activity interventions; dance lessons and ice-skating. Therapy-based interventions were found beneficial by two (18%) studies, one of which, a qualitative study, provided evidence of the positive perceived benefit from participants of regular peer-support groups, although changes in well-being were not measured nor observed with other standardised methods. One (9%) other found no difference in participants pre- and post-intervention after receiving child-centred play therapy. One demonstrated significant improvements in well-being, including reduced symptoms of anxiety and depression, after children had used hearing aids for 6 months. Two studies (18%) provided evidence on the effectiveness of intervention packages comprised of various approaches, including a package for obsessive–compulsive disorder. Of those described, five (45%) demonstrated improvements in scores on quantitative standardised measurement tools (such as the Strengths and Difficulties Questionnaire) after the intervention was implemented, of which four (36%) RCTs showed significant improvement in the intervention group and not the control group.With regards to behavioural problems, 11 studies reported on outcomes, of which all but one found some evidence of a positive impact of the intervention. Five (45%) found evidence on the benefit of training programmes, including parent behaviour training and teacher delivered resilience behaviour training for children. Three (27%) demonstrated the positive impact of therapy-based interventions on behaviour, although one (9%) showed no benefit. One study (9%) showed improvements among children on the Strengths and Difficulties Questionnaire, including the behavioural domain, after regular ice-skating sessions. One (9%) showed the benefit of a triadic intervention model for behavioural problems, focused on a core of reinforcement in schools. Seven (64%) reported positive improvements in behavioural outcomes, assessed through standardised measurement tools. Three RCTs (27%) demonstrated significant improvement in the intervention group and not the control, after delivery.Four articles provided evidence about the acceptability of the intervention to participants, delivery agents and/or parents. In one pilot study, this was the primary outcome that was measured quantitatively by questionnaire, with participants reporting good acceptance of the counselling method provided to support psychological well-being. In another, teachers reported feeling motivated to deliver the functional communication training for behavioural problems, and were happy with the training provided. In the third, both parents and delivery agents (clinicians) provided positive feedback in a directed workshop, with regards to the structure and components of the Webster-Stratton programme for behavioural problems. In the final case study of parent–child interaction therapy for behavioural problem, the mother expressed the value of learning to play with her child and manage their behaviour in a way that was fun and engaging for them.To the best of our knowledge, this is the first attempt to systematically identify and map the evidence on mental health support for children and adolescents with hearing loss. The scoping review identified 27 articles, two-thirds of which were conducted in the USA and two-thirds published before 2010. A number of interventions and support initiatives were described in the literature, including a broad range of therapy and counselling, and targeted training programmes, for both children and caregivers.47 As the evidence suggests, an effective and sustainable approach to child mental health includes support from an early age, improving information and awareness, providing social and emotional learning activities, increasing detection and identification, and improving access to treatment and rehabilitation. The interventions in this review provide some examples of interventions that may be effective within such a system, although as we will go on to discuss, the strength of the current evidence is limited.The interventions identified were, by and large, found to be effective at supporting the mental health and well-being of children with hearing loss. Although not all articles provided information on outcomes, nor all via quantitative assessment, those that did offered some encouraging signs as to the benefits of mental health support for children with hearing loss. Dance lessons, resilience training programmes and hearing aids demonstrate the diverse gamut of effective interventions that can be utilised to support children with hearing loss. Interventions provided treatment, prevention and promotion options in various settings, supporting recent advocacy for population- and community-level support for child mental health.48 Interventions at school level provide a continuum of care that benefits a child's mental health, as well as their educational attainment. Only one identified intervention was conducted within a mainstream classroom, despite the recent global movement towards inclusive education.49 That said, a recent report outlines the limited transformations in education systems across the world, with most countries facing difficulties in inclusive provision, with understanding of what this means, and resources and evidence on good practice variable across regions.50 As reform continues to spread, there will need to be evidence gathered on appropriate mental health interventions in inclusive classrooms, to ensure children with hearing loss are not excluded.Most of the interventions identified in this review were provided in school, which follows evidence from among the general population as to the benefits of integrated mental health provision within education systems.51 In some settings  such as the UK, and as seen in the included article from Wright et al (2012), specialist mental health services exist for children with hearing loss, where sign language and other accommodations are embedded in the service provided.46 However, in other settings, provision of communication technologies and sign language interpretation may not always be possible, given restricted resources. Often, and especially in low- and middle-income countries, mental health interventions are adapted from one context to another, in order to meet the culture, needs and resources of a population. In low- and middle-income countries, this often includes adapting interventions developed in high-income settings, although there are good examples of adaptation in the other direction, in which we see novel and effective mental health interventions developed in low-resource settings and adapted to those in high-income settings .52 Adaptation is common and needed, and the well-evidenced stages of this process should be noted by those looking to adapt mental health interventions for children with hearing loss, in order to ensure appropriate intervention components and delivery mechanisms. This will include standard adaptations to the context, but also specific adaptation to the needs of children with hearing loss, such as those seen in this review. We did not find any studies that provided evidence of an adaptation process through formative research, theory of change workshop, feasibility study, or similar methods, and this would be a useful area of research going forwards, to promote interventions for children with hearing loss that are contextually and culturally appropriate, and hopefully then effective and sustainable. These approaches also promote the participation of stakeholders, including those with hearing loss and/or mental health conditions.When considering interventions for children with hearing loss, it is important to note components and delivery methods unique to this group. Many of the interventions were initially developed for use in the general population, and more than half of the included articles described interventions that had been developed from evidence for children without hearing loss and adapted for the needs of children with hearing loss. Adaptations were most commonly focused on communication, and often sign language. Communication is often cited as a major barrier and facilitator to accessing healthcare for people with hearing loss, and it is appropriate to see this as the focus of many adaptations.53 Despite an increased focus on global mental health and disability rights, this review suggests that mental health support for children with hearing loss is not gaining sufficient interest in the research community. The Lancet Commission on Global Mental Health and Sustainable Development, published in 2018, may stimulate additional research in the future, calling as it does for a focus on culturally appropriate and participatory approaches to translating evidence for promotion and care in mental health across diverse populations.54 Our approach to classification using a continuum from well-being to mental health diagnosis draws on these ideas. Exploring the evidence among adult populations is also needed given the higher prevalence of hearing loss in this age group.Although 27 articles were identified, there is concern about the breadth, scope and strength of the evidence within the literature available. With two-thirds (67%) of articles published before 2010, and 41% pre-2000, it is evident that the published literature on this topic is not growing at a fast rate. Interest and research in disability has steadily increased since the United Nations Convention on the Rights of Persons with Disabilities (2008), and calls for further evidence on scalable mental health interventions have been delivered by leading figures for many years.55 Relying on data from high-income settings has caused concern in the field of global mental health, as doing so reduces long-term effectiveness and sustainability of mental health interventions, especially when biomedical models of care are transferred to settings where they may not be culturally accepted, contextually feasible or appropriate.54 There is growing evidence on new and adapted mental health interventions for the general population in low- and middle-income settings, and as shown in this review, there is the possibility of adapting these to suit the needs of children with hearing loss (for example sign language provision). Evidence is needed on the process of adaptation and contextualisation, in order to inform delivery in the given country, and to provide a research framework for others.Furthermore, nearly all (81%) of the included articles come from high-income settings, with two-thirds (67%) conducted in the USA. Just one (4%) was conducted in a lower-middle or low-income setting. There are no articles from Latin America or Africa, and just one study from Asia. The geographical scope of study into appropriate interventions for children with hearing loss must increase. Given that 80% of the world's population and people with disabilities are living in low- and middle-income countries, there is an urgent need for evidence on contextualised interventions.Most of the studies were assessed to have medium or high risk of bias. Just six (22%) of the studies available and included are RCTs. The majority of included articles offer interesting case reports, but these provide the rationale for larger-scale trials, rather than high-quality evidence in and of themselves. Most of the studies included have also been conducted with very small sample sizes. Nearly half (48%) of studies contained a sample size smaller than 20, increasing to two-thirds (67%) when including those articles with no sample size available. To improve the evidence base with which to stimulate service provision and policy, there needs to be experimental research, with large samples, with which to build confident conclusions and inform scalable interventions. Potential sources of bias must be addressed, including appropriate statistical methods, including sample size calculations for sufficient power.18 Such consultation is time-consuming and costly, and was not feasible when undertaking this study, and may be an important area to address in any future and updated reviews.There are several limitations to this review. First, we excluded articles that were not in the English language, and there may well be evidence missed that has been published in other languages. This is particularly important when considering the limited evidence from South America and East Asia. Our age range, 6–18 years, is broad and although not necessarily a limitation, it is important that readers of this review pay close attention to the targeted age range of interventions of interest. Younger children and older adolescents will respond differently to interventions, and will have different mental health needs, and not all interventions will be applicable across age groups. Second, we could not source 19 full-text articles, in which there may have been relevant and included studies. We contacted authors directly and utilised various institutional access agreements, but still could not find these for assessment. Third, we did not assess publication bias. When interpreting the results on effectiveness, readers should be conscious of the risk of positive publication bias and a potential lack of interest to publish results on ineffective interventions. Finally, in their framework for scoping reviews, Arksey & O'Malley recommend an optional sixth step; consultation with stakeholders.This review has identified a number of articles and interventions, which generally showed positive results, but there are concerns over the breadth of the evidence available. There is evidence of some effective interventions, such as dance lessons and resilience training, but the applicability of the available evidence is limited by geographic location and publication date, and there is a need for more studies applying high-quality research methods. To improve the current evidence base, we must strengthen the quality of the research methods used and provide further research from low- and middle-income countries on adapting interventions to local contexts and on interventions tested at scale. Having a community of researchers set future research priorities, as informed by practitioners and people affected, will focus and strengthen research activities going forwards.Peer-support: children with hearing loss can benefit from interaction with peers, reducing isolation, while helping them learn more about themselves and their experience as a child with hearing loss. Peer-support can act as both a treatment and health promotion option.Resilience training: identified by a number of studies in this review, resilience training may be an effective way of preventing mental health conditions, especially if implemented at an early age. This type of training may be particularly appropriate to integrate into schools.Emotional and behavioural management training: this type of structured training programme can be provided for both parents and children. Helping parents learn the tools with which to support their child's emotional regulation and behaviour may help create a home environment that promotes well-being and positive coping strategies. Training children themselves, possibly in school, will further help children with hearing loss build the toolkit with which to understand and approach the challenges they face.Physical activity: physical activity is a simple way to build well-being and promote mental health. In this review, the physical interventions identified were specialist in nature – ice-skating and dance therapy are not necessarily available in all settings – but adapting these techniques and principles to a different context may prove effective.Consider the intervention models identified in this review, including the following.Knowledge and awareness: it is important that the delivery agent is given appropriate training and sensitisation on disability and hearing loss. There may also be cause to provide information to children without hearing loss in the same setting, in order to reduce any apparent stigma or discrimination; for example, to hearing children in a mainstream classroom.Communication methods: each child will have different communication needs, depending on their severity of hearing loss and personal preferences. Include appropriate training for delivery agents on communication methods, including clarity of speech and the language used. Where necessary, provide sign language interpretation, and where relevant provide training on hearing aid or cochlear implant use, as this knowledge will facilitate improved communication and reduce stigma.Physical environment: consider the environment in which the intervention is delivered. This may be a mainstream classroom, for instance, that is not set up to accommodate the needs of children with hearing loss. Considering the configuration of seating in a group is one example; children sitting in a circle may help improve visual contact and support those who lipread. Keeping the environment quiet and free from distractions will also help children with hearing loss, as might keeping the door closed and adding soft material to the underside of chairs.Intervention materials and techniques: where suitable, use visual aids and cues to support the intervention components. One example may include pictures matched to emotions, to aid the understanding and communication of feelings. Other techniques to reinforce behaviours and actions may include role-play, storytelling and peer-feedback.Consider the following when adapting or developing an intervention.Interventions identified in this review benefitted from clear communication and coordination between different groups involved. For instance, interventions in schools were strengthened when teachers and parents worked together.Conduct feasibility studies and pilot studies, where possible, in order to make any necessary amendments early in the implementation process. This will also help inform others in the future.Providing a range of interventions within a service or facility (such as a school), where this is feasible, may provide the best model with which to support a personalised approach for each child.Consider the following during intervention development and implementation.Consult the children, their parents, mental health and hearing specialists, and the delivery agents (such as teachers). Understand their needs and context in the adaptation or development phase.In all, talk to the children who are the intended target of the intervention about their own needs and preferences for intervention components, including communication methods.Consultation and coordination may help promote feasible, acceptable and sustainable intervention programmes.Based on the findings of this review, we have listed below a number of considerations for delivering mental health support for children with hearing loss, including adaptations to existing mental health interventions.


Background: The definition of notched audiogram for noise-induced hearing loss (NIHL) is presently based on clinical experience, but audiometric phenotypes of NIHL are highly heterogeneous. The data-driven clustering of subtypes could provide refined characteristics of NIHL, and help identify individuals with typical NIHL at diagnosis.Methods: This cross-sectional study initially recruited 12,218 occupational noise-exposed employees aged 18–60 years from two factories of a shipyard in Eastern China. Of these, 10,307 subjects with no history of otological injurie or disease, family history of hearing loss, or history of ototoxic drug use were eventually enrolled. All these subjects completed health behavior questionnaires, cumulative noise exposure (CNE) measurement, and pure-tone audiometry. We did data-driven cluster analysis (k-means clustering) in subjects with hearing loss audiograms  consist of two independent datasets . Multinomial logistic regression was performed to analyze the relevant characteristics of subjects with different audiometric phenotypes compared to those subjects with normal hearing audiograms .Results: A total of 10,307 subjects  were included, 3,708 (36.0%) of them had completely normal hearing, the other 6,599 (64.0%) with hearing loss audiograms were clustered into four audiometric phenotypes, which were replicable in two distinct datasets. We named the four clusters as the 4–6 kHz sharp-notched, 4–6 kHz flat-notched, 3–8 kHz notched, and 1–8 kHz notched audiogram. Among them, except for the 4–6 kHz flat-notched audiogram which was not significantly related to NIHL, the other three phenotypes with different relevant characteristics were strongly associated with noise exposure. In particular, the 4–6 kHz sharp-notched audiogram might be a typical subtype of NIHL.Conclusions: By data-driven cluster analysis of the large-scale noise-exposed population, we identified three audiometric phenotypes associated with distinct NIHL subtypes. Data-driven sub-stratification of audiograms might eventually contribute to the precise diagnosis and treatment of NIHL. Noise-induced hearing loss (NIHL) is one of the most common hearing loss in adults , with inIt is widely accepted that the noise exposure usually causes high-frequency sensorineural hearing impairment , 8. DespGenerally, descriptions of NIHL phenotypes are limited by subjectivity and poor data support. A data-driven classification that incorporates the multifrequency audiogram of NIHL is needed to identify subtypes with consistent patterns and characteristics. Cluster analysis is an unsupervised exploratory data mining technique able to group the most similar individuals with multiple specified variables in the same group called “cluster” without any previously defined hypothesis . Since aIn the current study, based on audiograms of 10,307 Chinese shipyard employees with various noise exposure levels, we used the k-means clustering algorithm to classify subtypes of NIHL in two distinct noise-exposed populations from different factories. The confounding influencing factors related to these subtypes were further analyzed to optimize the assessment for different subtypes of NIHL, which could provide a powerful tool to identify those individuals at great risk of NIHL and guide optimal prevention of noise exposure.We conducted this hearing and health investigation in a shipyard in eastern China from August 1, 2017, to June 30, 2018. A total of 12,218 subjects aged 18–60 years were initially recruited, and 10,307 from two steel factories  were included in the analysis based on the following criteria: (1) completed questionnaire and audiometric data, (2) no history of otological injuries or diseases, (3) no family history of hearing loss, (4) no history of ototoxic drug use, (5) no profound hearing loss (average threshold at 0.5–2 kHz frequencies >70 dB HL in any ear), and (6) no perforation of tympanic membrane or abnormal tympanogram. Sex and race were self-reported. Pure-tone air-conduction audiometry at frequencies of 0.5, 1, 2, 3, 4, 6, and 8 kHz in both ears was performed by certified audiological technicians using an audiometer  with TDH-39P headsets in a soundproof booth in accordance with the regulations of ISO 8253-1: 2010. The subjects were not exposed to occupational noise or loud sounds within 16 h before being examined. The average threshold of the left and right ears at each frequency was calculated for subsequent analysis without the age-correction according to ISO 7029: 2017, in order to avoid the artificial modification on the subsequent cluster analysis. Normal hearing was defined as hearing threshold ≤25 dB HL over 0.5–8 kHz frequencies. Hearing loss was defined as hearing threshold >25 dB HL at any frequency.2) and obese (≥28 kg/m2) groups.Demographic variables  and behavioral characteristics, including hearing protection device (HPD) use , personal earphone use , tobacco  and alcohol  consumption, and auditory-related symptoms (hearing difficulty and tinnitus), were collected through a self-reported questionnaire. Body mass index (BMI) was measured and calculated by investigators, and then categorized into non-obese , was used to estimate the noise exposure level for each subject, which was calculated using the following formula :LAeq,8h is the equivalent sound pressure level in A weight of 8 continuous hours of a work-day, which was measured and analyzed using the personal exposure dosimeter . Subjects were required to wear the dosimeter on the shoulder for five work-days to calculate the average LAeq,8h. T is the working time-length in years obtained from the questionnaire.where Seven variables including standardized values of thresholds at frequencies of 0.5, 1, 2, 3, 4, 6, and 8 kHz were input for k-means cluster analysis performed using R software (version 4.0.3) . The optn [%]). Statistical significance for differences in continuous variables was examined using Student's t test (between dataset 1 and dataset 2) or ANOVA , and categorical variables were compared by the chi-square test. Multinomial logistic regression models were used to analyze relevant factors of different clusters of audiometric subtypes. For the hierarchical regression, age was categorized into 3 groups . For all models, odds ratios (ORs) and 95% confidence intervals (CIs) are presented. A 2-tailed P < 0.05 was considered statistically significant.Data analysis was performed by using IBM SPSS version 24.0 software  except for cluster analysis. Continuous variables are expressed as the mean , and categorical variables are presented as percentages  were included. Among all subjects, 3,708 (36.0%) had completely normal hearing over 0.5–8 kHz frequencies. The total subjects were recruited from two independent factories in a shipyard, who had similar types of occupational tasks, despite significantly different distributions of sex, age, CNE, hearing loss, and other characteristics. The distributions of age, CNE, sex, BMI, hearing difficulty, tinnitus, HPD use, earphone use, tobacco consumption, and alcohol consumption are shown in n = 6,599), dataset 1  and dataset 2  to verify that the cluster structure described for each dataset was reproducible.To classify NIHL into novel audiometric phenotypes, we used the k-means clustering method in audiograms with hearing loss. We repeated the cluster process, respectively, in total dataset . In comparison with the 4–6 kHz sharp- and flat-notched subtypes, subjects manifested as the 3–8 kHz and 1–8 kHz notched subtypes were significantly older, with higher noise exposure, as well as higher proportions of males, hearing difficulties and tinnitus. In post-hoc analyses, for the 4–6 kHz flat-notched audiogram, the average age of subjects of this subtype was similar (P = 0.293) to that of the 4–6 kHz sharp-notched audiogram, while the mean CNE was slightly smaller (P = 0.008) than that of the 4–6 kHz sharp-notched audiogram, but significantly larger (P < 0.001) than that of the normal-hearing audiogram. The proportions of females, hearing difficulties, tinnitus, and earphone uses were higher in subjects with the 4–6 kHz flat-notched audiogram than that in the 4–6 kHz sharp-notched audiogram. Moreover, the average hearing thresholds of the 4–6 kHz flat-notched audiogram at frequencies of 0.5–3 kHz were obviously higher than that of the 4–6 kHz sharp-notched audiogram . The detailed distribution of characteristics in subjects with different audiometric phenotypes is shown in Audiograms with hearing loss were then classified into 4 subtypes for cluster analysis of the total dataset, which were named 4–6 kHz sharp-notched . According to the adjusted ORs of noise exposure dose for different phenotypes after stratification, the increment of CNE was stably associated with the 4–6 kHz sharp-notched phenotype , as welln = 6,599), we developed the cluster model and identified four phenotypes with distinct audiogram subtypes of hearing loss. We repeated the cluster analysis in two independent parts of the total dataset, dataset 1  and dataset 2  where we were able to replicate the clusters into four similar phenotypes. The relevant demographic and behavioral characteristics of population with different hearing loss phenotypes were analyzed in comparison with the normal hearing population .In this study we performed a cluster analysis of noise-exposed population who had some degree of hearing loss. By using the audiometric thresholds over 0.5–8 kHz of the total hearing loss dataset (Our main finding was that hearing loss in noise-exposed population consisted of four audiogram subtypes that had different characteristics and associations with noise exposure levels. In line with previous studies, we found the presence of a “notch” at high frequencies of 3, 4, and 6 kHz with recovery at 8 kHz in most hearing loss audiograms, some of which extended to involve even 1 kHz and 2 kHz –16. TherIn the present study, the 4–6 kHz sharp-notched audiogram, 3–8 kHz notched audiogram, and 1–8 kHz notched audiogram were strongly related to noise exposure, which represented three distinct subtypes of NIHL. This result supported the conventional description of noise-induced high-frequency audiometric notches , 23 baseIn particular, the 4–6 kHz flat-notched audiogram was the second most common subtype of hearing loss after the 4–6 kHz sharp-notched audiogram, however, it seemed to be unrelated to noise exposure, but associated with age, sex, and some behavioral factors according to the logistic regression . AlthougAs many previous studies reported , 28, 29,It is widely accepted that audiometric phenotypes are based on presumed underlying auditory histopathology, which suggests the causes and degree of auditory organ damage , 33. A fThe main strength of our study is that it first provides various reproducible audiometric subtypes of NIHL by data-driven analysis in a relatively large-scale noise-exposed population. Another strength was that our study was based on consideration of detailed noise exposure history, questionnaire information and audiometric data from standardized protocols, which can give a more nuanced picture than clinical data. Previously Zhao et al. developed machine learning models for the prediction of NIHL , which wIn conclusion, we were able to repeat and identify distinct audiometric phenotypes of NIHL in large-scale noise-exposed populations with different relevant characteristics, by using cluster analysis. Moreover, given the technological advances in machine learning, our study provides a sight into the prospect of involving data-driven audiogram mining for the precise diagnosis and treatment of NIHL in future studies.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding authors.The studies involving human participants were reviewed and approved by the Ethics Committee of the Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. The patients/participants provided their written informed consent to participate in this study.QW, MQ, ZH, and HW: contributed to the study design. QW and MQ: writing the original draft. MQ, LY, JS, YH, and KH: contributed to the acquisition of data. QW, CL, and JL contributed to the analysis of data, ZH and HW contributed to the supervision and funding acquisition of the work, review and revision of the draft. All authors contributed to the interpretation of data and critical revision of the draft. All authors gave final approval of the version to be published.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Scientific Reportshttps://doi.org/10.1038/s41598-020-70032-y, published online 20 August 2020Correction to: This Article contained errors.The version of this Article previously published quoted an incorrect email address for Hanan H. Abd-Elhafeez. Correspondence and requests for materials should be addressed to hhnnzz91@aun.edu.egFurthermore, the legend of Figure 14,A) scanned sample of the intestinal blub. Note the epithelium , lamina propria , muscle .  TCs network (blue colored) in the lamina propria. Note connected teloped (pink colored). (D–F) TCs (blue colored) between muscle bundles (red colored).  TC network between muscle fibers (reddish brown colored). Note serosa (violet colored). (H) TCs in serosa.”“Scanned muscular TCs. (now reads:A) scanned sample of the intestinal blub. Note the epithelium (ep), lamina propria , muscle .  TCs network (blue colored) in the lamina propria. Note connected teloped (pink colored). (D–F) TCs (blue colored) between muscle bundles (red colored).  TC network between muscle fibers (brown colored). Note connetced teloped (pink colored). (H) TCs (blue color) in serosa.”“Scanned muscular TCs. (Lastly, in the Conclusion section,“The current study presented the relation of TCs with different types of immune cells in the intestinal bulb of the Grass carp [17].”now reads:“The current study presented the relation of TCs with different types of immune cells in the intestinal bulb of the Grass carp.”These errors have now been corrected in the PDF and HTML versions of the Article.


To present the extent and site of lesion of auditory dysfunction in a large cohort of individuals with type 2 Stickler Syndrome. Type 2 Stickler Syndrome results from a mutation in the gene coding for α-1 type XI pro-collagen, which has been identified in the human vitreous, cartilage and the cochlea of the mouse. The condition is characterised by classic ocular abnormalities, auditory dysfunction, osteoarthropathy and oro-facial dysplasia.This is a population study which used a combination of audiometric, tympanometric, and self-report measures on a series of 65 individuals  with genetically confirmed type 2 Stickler Syndrome.Hearing impairment was identified in at least one ear for 69% of individuals. Analysis against age-matched normative data showed that reduced hearing sensitivity was present across all test frequencies. Sensorineural hearing loss was most common (77% of ears), with conductive (3%), mixed (7%) and no hearing loss (13%), respectively. The proportion of hypermobile tympanic membranes (24%) was less than previously documented in type 1 Stickler Syndrome. When present, this appears to arise as a direct result of collagen abnormalities in the middle ear. Self-report measures of speech and spatial hearing in sound were comparable to a non-syndromic cohort with similar audiometric thresholds.Auditory impairment in type 2 Stickler Syndrome is predominantly associated with cochlear hearing loss of varying severities across affected individuals. The impact on hearing thresholds can be seen across the frequency range, suggesting a contribution of defective collagen throughout the cochlea. Self-report questionnaires showed that difficulties understanding speech, and spatial information in sound , were worse than a young, normal-hearing population but comparable to a non-syndromic cohort with similar audiometric thresholds. Therefore, it is likely that hearing loss in type 2 Stickler Syndrome arises in the auditory periphery, without significant central processing deficits. In 1965, Dr. Gunnar Stickler and colleagues described a dominant “hereditary arthro-ophthalmopathy” characterised by premature degenerative osteoarthropathy, and progressive myopia beginning in the first decade of life and frequently resulting in retinal detachment and blindness , 3, but Mild hearing loss, affecting the mid- to high frequencies, was first associated with this condition by Stickler and Pugh in 1967 , 9, whicHearing loss is thought to be more common and more severe in type 2 Stickler Syndrome, caused by mutations in COL11A1, than in type 1 Stickler syndrome. In the first description of the Stickler Syndrome associated with a COL11A1 mutation, Richards et al. , reporteRelatively few studies have described the auditory phenotype of the Stickler Syndromes in detail. Acke et al.  conducteSzymko-Bennett and colleagues assessed auditory dysfunction by means of audiometry and tympanometry in 46 Stickler Syndrome patients from 26 family pedigrees . When heHearing assessment of only a limited number of individuals with type 2 Stickler Syndrome have been reported in the literature, which motivates the need to study and report a larger population. Furthermore, there is a lack of information guiding how classifications of severity and aetiology should be made, and much variation in reporting, where this information is available in the Stickler Syndromes. Consequently, to establish the relative contribution of type 2 Stickler Syndrome on hearing impairment, in the context of the expected role of ageing of the auditory system (presbyacusis), careful comparison of findings with age- and gender-matched normative data is required.The aim of the present study was to examine the auditory phenotype of individuals with genetically confirmed type 2 Stickler Syndrome. We aimed to compare the relative proportions of conductive/mixed and sensorineural losses, and re-examine reports that hearing loss in type 2 Stickler Syndrome is restricted to high frequencies by comparing hearing thresholds with age- and gender-matched normative data. Tympanometry was used to determine the proportion of individuals with hypermobile tympanic membranes to facilitate comparison with previous studies. To ascertain if tympanic membrane hypermobility is acquired through repeated infection-related trauma, a clinical questionnaire regarding previous history of ear infections and otological symptoms was collected. In addition, results of a clinically validated hearing loss questionnaire, are reported and compared to data from a population with similar audiometric profiles due to ‘typical’ aetiologies that contribute to hearing loss. If hearing difficulties reported were significantly greater in the Stickler population than the comparative population, this would suggest a potential role of central auditory processing alongside peripheral auditory impairment.This is the largest cohort of genetically confirmed type 2 Stickler Syndrome patients in the literature, and the only report detailing the auditory phenotype in this sub-group of the disorder.Subjects with genetically confirmed type 2 Stickler Syndrome were recruited via the Nationally Commissioned Highly Specialised Stickler Syndrome diagnostic service held at Cambridge University Hospitals, UK (CUH). Data collected on each patient included demographics, otological history, pure-tone audiometry (PTA), tympanometry, and clinically validated auditory handicap questionnaires. This project was conducted following National Research Ethics Service approval (10/H0301/57).Past otological history was assessed using a bespoke patient questionnaire (see appendix 2.1). The questionnaire documented subjective accounts of ear-related pathology, including self-reported hearing loss, frequency of ear infections, history of otological surgery and potential otological symptoms associated with auditory dysfunction.Pure-tone audiometry was undertaken in a sound proofed booth following the Recommended Procedure of the British Society of Audiology  utilisin3 were considered as hypermobile and labelled as Ad had a hearing loss in at least one ear. A mild hearing loss in the better ear was the most common presentation, affecting 46% [30/65] of the population. The majority of hearing loss was bilateral and symmetrical. The proportion of individuals with different configurations of hearing loss is shown in more detail in Table The aetiology of hearing loss was assessed by PTA on an ear-by-ear basis. A total of 102 ears of 65 patients were included, following exclusion of ears, where underlying aetiology could not be reliably established. The distribution of aetiologies, categorised according to age is shown in Fig. Averaged hearing thresholds, presented as an audiogram for three different age groups of patients with type 2 Stickler Syndrome, are shown in Fig. χ2 and p values, is shown in Table χ2 = 54.16, p < 0.01). McNemar’s pairwise comparisons (with Bonferroni corrections for multiple comparisons) indicated a complex relationship between frequency pairs and is not consistent with an obvious monotonic trend for greater hearing loss at higher audiometric frequency.The proportion of ears with sensorineural hearing loss identified to have thresholds falling outside the 95th percentile for each test frequency using age-specific audiometric data, along with corresponding d).Tympanometry results were assessed on an individual ear basis. Results were available for 90 ears. Forty-two (47%) tympanic membranes demonstrated normal type A tympanograms, 10 (11%) were classified as type B, 12 (13%) had negative middle ear pressure (type C) and 4 (5%) had perforations; 22 (24%) of examined tympanic membranes were hypercompliant (type Ad hypercompliant tympanogram.Tympanometry categories correlated to the different aetiologies of hearing loss for 39 ears (measurements for both made on the same day) are shown in Fig. d hypercompliant tympanogram who completed the questionnaire reported regular ear infections; of the 18 patients without hypercompliant tympanograms who completed the questionnaire, five patients reported regular ear infections, suggesting ear infections were more common in patients that did not have type Ad tympanograms.To assess whether hypercompliant tympanograms were linked to a history of recurrent ear infections, tympanogram outcomes were correlated to the reported otological history of previous ear infection. Only one of the eight patients with a type AForty-five patients completed the otological symptoms questionnaire. Thirty-four (77%) reported some degree of hearing impairment and eight (18%) reported recurrent ear infections, with a mean of three infections a year.t test: t = 9.25), but there was no significant difference between the Stickler cohort and a group of individuals with mild–moderate bilateral sensorineural hearing loss . The results from the Stickler type 2 population show that individuals tend to report similar difficulty when discriminating speech, in identifying the properties of sound perception linked to spatial perception, and the quality of sound perception. This is similar to the findings of Demeester et a.l,  of individuals had hearing loss in at least one ear, and the majority of hearing loss was symmetrical. In patients with hearing loss, typically the severity was mild (75% of patients with loss), bilateral (87% of patients with a loss) and sensorineural (77% of ears). The selection of the 4-FA as the metric for hearing impairment was chosen, because it most accurately reflects a hearing loss likely to impair an individual’s ability to follow a conversation. It is relatively conservative as an identifier of hearing loss—for example using a model for age-related sensorineural hearing loss, zero individuals would be expected to have 4-FA greater than 20 dB HL in a population of healthy individuals with only age-related hearing loss of the same size as the cohort examined here. Thus it can be concluded that just over two-thirds of the population tested had hearing loss that can likely be attributed to type 2 Stickler Syndrome. If the least conservative metric for hearing loss is used (any one pure-tone frequency in excess of 20 dB HL), the proportion of individuals with a hearing loss rises to 94%, but this is likely to include individuals with hearing loss attributable to ageing. Furthermore, in keeping with previous studies, audiograms generally displayed a greater impairment in the higher frequency regions . HoweverComparison of self-report disability scores obtained from this population and a young normal-hearing group showed the expected increase in reported difficulty, applying to speech discrimination, as well as spatial and sound quality perception . When coThe exact pathophysiology of Stickler Syndrome type 2 associated hearing impairment remains unknown. Temporal bone computed tomography (CT) scans have revealed no macro-deformity of the inner ear . The und24% of patients were found to have hypermobile tympanic membranes; this is lower than the incidence of 36–46% reported in type 1 Stickler Syndrome patients , 29. OtoA reticence to test below 20 dBHL for a clinical assessment may have potentially introduced testing bias, with the potential for over emphasising differences between the study population and age-matched normative data for mid- and low-frequencies thresholds. However, the existing data suggest the severity of hearing loss in those patients found to have mid- and low-frequency thresholds outside the normal range would not have been affected by this ‘floor’ effect. Thus, low frequency hearing loss reported in the current type 2 Stickler Syndrome population is unlikely to be an artefact, and confirms with previously reported studies .The tympanometry protocol performed in this study utilised probe tones at 226 Hz. Whilst useful clinical information was gleaned, recently developed wideband acoustic immittance techniques describe middle ear function across a wide frequency range, and normative data is now available . Future This is the largest study investigating audiological phenotype of genetically confirmed type 2 Stickler individuals. The dataset comprises pure-tone audiometry and tympanometry, as well as self-reported handicap and otological pathology information. The study is also the first to consider age–gender matched normative data with regards to hearing impairment in the type 2 Stickler Syndrome. Details are included of how hearing loss aetiology and severity are classified, which is often lacking in previous studies, in addition to strict criteria when defining hearing loss. A high prevalence of cochlear hearing loss, with evidence of dysfunction across the audible frequency range, rather than restricted to the high-frequencies, was demonstrated. Hypermobile tympanograms are likely to be due to intrinsic tympanic membrane defects, rather than associated with previous perforations due to otitis media, but are less common than in type 1 Stickler Syndrome.


The acceleration component in the orthogonal direction, the radial acceleration, fluctuated around a negative mean of more than 4g showing that the surrogate head was continuously subjected to centripetal forces caused by rotations.Violent shaking is believed to be a common mechanism of injury in pediatric abusive head trauma. Typical intracranial injuries include subdural and retinal hemorrhages. Using a laboratory surrogate model we conducted experiments evaluating the head motion patterns that may occur in violent shaking. An anthropomorphic test device  matching an infant of 3.5 kg was assembled. The head interior was equipped with accelerometers enabling assessment of three-axial accelerations. Fifteen volunteers were asked to shake the surrogate vigorously holding a firm grip around the torso. We observed the volunteers performing manual shaking of the surrogate at a median duration of 15.5 sec (range 5–54 sec). Typical acceleration/deceleration patterns were produced after 2–3 shakes with a steady-state shaking motion at a pace of 4–6 cycles (back and forth) per second. Mean peak sagittal tangential accelerations at the vertex were 45.7This surrogate experiment showed that violent shaking may induce high peak tangential accelerations and concomitantly a continuous high-magnitude centripetal force. We hypothesize that the latter component may cause increased pressure in the subdural compartment in the cranial roof and may cause constant compression of the brain and possibly increased stretching or shearing of the bridging veins. This may contribute to the mechanism accountable for subdural hematoma in abusive head trauma. This clinical evidence along with the sometimes questionable admissions by perpetrators, form the basis of the hypothesis that violent shaking alone, without impact to the head, may cause severe intracranial injuries.5 Such cases could be referred to as inflicted head injury by shaking trauma (IHI-ST).7Abusive head trauma (AHT) is a major cause of morbidity and mortality in infants and young children.8–11 However, impact trauma differs largely from violent shaking events, especially concerning the duration of the acceleration peaks and the repeated loading due to the cyclic motion. Further, the loads generated by an impact depend on various factors, such as the elastic properties of the surrogate's surface and skull and the impact direction. Therefore, it is highly questionable whether using impact thresholds on non-impact repeated shaking is valid.Biomechanical experiments with manual shaking of surrogates/dummies equipped with sensors have been performed in previous studies, but the accelerations measured have been below the commonly applied injury thresholds for impact trauma in adults.10 or were triaxial but without reporting of the accelerations in all directions.11 Estimates of rotational accelerations were provided based on calculations that ignore the fact that not only does the head rotate with respect to the body, but the body also moves and rotates through space. Yet, such measurements are, from a kinematics point of view, essential to fully grasp the mechanisms potentially underlying IHI-ST. To our knowledge, no biomechanical experiments that measured the head motion pattern and linear accelerations involved in violent shaking in three dimensions  have been reported in the literature. The aim of the present study was to quantify the 3D linear accelerations in repeated shaking to explore possible injury mechanisms.Previous biomechanical surrogate experiments applied simple neck joints such as hinges or short rubber necks. The accelerometers used were usually uniaxial in the anterior-posterior planeAn anthropometric test device (ATD), a human surrogate proportionate to a 1-month-old infant , Q0 dummThe axis of the neck contains a 2-mm diameter steel wire for limiting the neck movements within biofidelic borders. The surrogate was calibrated and tested by the manufacturer before the experiment.g; Silicon Design Inc.), one on each side  in the direction orthogonal to their flat side and were arranged to measure in a right-handed coordinate system: The two accelerometers measuring anteroior-posterior movement (X1 and X2) were mounted on the frontal and occipital side of the bracket, providing positive measurements in the forward direction (occiput to nose); accelerometers Y1 and Y2 were mounted on the lateral sides, providing measurements in a positive direction from right to left; and accelerometers Z1 and Z2 were placed on the top and bottom of the bracket, providing measurements in a positive direction upwards. Using paired sensors placed spatially apart on the same axis improves the measurement robustness, allowing easy detection of any eventual sensor failure, and allowing determining rotations. A seventh uniaxial accelerometer was mounted on the vertex of the head  LabView program and a NI USB 6251 Data Logging Device.g, slight absolute acceleration drift. Before measurements, the setup was calibrated by successively aligning the three measurement axes with gravity and adjusting their offset to display 1g. Intermediate brief drop tests displayed only marginal differences between the readings of any pair of sensors.Accelerations were sampled at ∼1 kHz, which was well below the accelerometers' maximum measurement frequency, and were stored in raw, unfiltered format during the experiments. The measurement sensitivity was ∼0.1Nine male and six female volunteers, 35 to 65 years of age, were asked to hold the surrogate with their hands in a firm grip around the torso and shake as violently and as long as they could. All volunteers shook face-to-face with the surrogate. Each volunteer performed two consecutive shaking tests. Before each test, the setup calibration was confirmed by putting the surrogate horizontally on a flat table. The experiments were video-taped using a camera at 25 frames/sec. For each volunteer, the test run with the highest two consecutive peak vertex accelerations was selected for further analysis to find a reliable worst-case scenario. All volunteers agreed with publishing the gathered data.g (range 14.2–105.1g). The mean peak accelerations in the skull center were 18.6g (range 6.5–36.2g) in the X-direction, 4.9g (range 2.5–11.7g) in the Y-direction, and −17.5g (range −5.2 to −44.0g) in the Z-direction.The mean duration of vigorous surrogate shaking performed by the volunteers was 15.5 sec (range 5–53 sec), with a mean back-and-forth shaking frequency of 4.6 Hz  was up to 3 times larger than in the negative (backwards) direction, as illustrated in It should be noted that during analysis it was discovered that after Volunteer 2 the measured values changed considerably. Further investigation revealed that the steel cable in the dummy neck had broken, which was assumed to have happened after Volunteer 2. Consequently, the first two volunteers showed considerably higher accelerations than the later volunteers. However, because this provided the opportunity to show the importance of proper neck and end-stop modeling favorable instantaneous center of rotation does not necessarily occur during the peak accelerations and values calculated by Duhaime and colleagues2.With the non-hinge necks, rotational speed and acceleration of the torso will be transferred to the head. However, this cannot be measured or calculated with a single sensor or a fixed rotation axis.3.A single sensor setup cannot distinguish between linear and rotational accelerations.In the current study, no rotational accelerations or rotational velocities are reported. That is because straightforward kinematics show that based on the sensors in the dummy alone the instantaneous axes of rotation or acceleration cannot be adequately determined and thus neither can the rotational velocity or acceleration. Duhaime and colleagues used a dummy with an accelerometer on the vertex of its head measuring what would be the vertex acceleration in our experiments.8 (8 Yet more importantly, this illustrated that proper determination of angular components requires the actual center of rotation to be known at all instances of the shaking cycle. Hence, existing published data about the loads acting on infants during fierce shaking should be carefully interpreted.To illustrate the importance of knowing the actual center of rotation, first the current peak vertex accelerations were used to calculate the peak angular velocity and acceleration in the same manner as by Duhaime and colleagues8 . Next, t8 . This sh14 Combined with the consistently negative Z-acceleration shown in the current study, this may become a harmful cocktail during shaking: increased stress in the bridging veins due to increase blood pressure, combined with rapid loading, which further increases the stresses due to the viscoelastic response, and repetitive cyclic loading that leads to rupture at early stress levels. With the instantaneous center of rotation close to the center of the head, the measured accelerations lead to angular velocities and angular accelerations (see 15 Human infant bridging veins seem to endure similar or slightly higher stretch and stress before rupturing, depending on the type of loading.15 This suggests that the measured accelerations could be in a harmful range if the transfer from skull kinematics to bridging vein loading is the same in infants as in piglets. However, the latter has yet to be investigated.Material tests on human infant bridging veins have shown that rupture occurs at much lower stresses after 30 sec of cyclic loading than after a single pull, and also that bridging veins break at lesser elongation for higher deformation rates.ions see  that are16 The surrogate neck in the present study is a scaled adult version that was designed to mimic the motion of a baby neck in high-energy trauma, such as car collisions. It is stiffer than in real infants, who possess little neck muscle tone and may not in such cases adequately support the weight of their heads. A highly flexible neck may allow more extreme head motion with respect to the torso at the end-points of the shaking motion. On the other hand, a stiffer neck transfers more of the rotational accelerations exerted on the torso to the head.A potential error source in the present study is the biofidelity of the surrogate's neck. Several studies have shown that more compliant necks result in higher peak accelerations than stiffer necks.10 all data were kept from the analyses, both due to uncertainty as to whether the intact neck cable was more realistic in terms of neck stiffness and impact, as well as to keep records of the changes that were made during the study.The measurements with the broken neck cable showed reduced peak accelerations but a rougher course of the accelerations in general . WithoutBecause a biofidelic neck, such as in the current tests, does not have a single axis of rotation, the location of the instantaneous axis with respect to the torso varies continuously during shaking and is not determined by geometric constraints alone. Further, during shaking the rotation with respect to the torso is at most instances not equal to the center of rotation with respect to earth, which determines the actual accelerations experienced by the dummy. Therefore, and because no orientation or position measurements were done, it was impossible to reliably determine the instantaneous centers of rotation and acceleration for the dummy head during shaking. Yet, the extent to which a combination of angular velocity and angular acceleration is harmful depends on where the center of rotation is located.As an example, consider the skull and brain as a cup and water, respectively. Then, consider the difference between the accelerations experienced by a cup of water at the center of a rotating disk and one on the outer edge of the same disk. Both cups and the water within will experience the same rotational acceleration and velocity, but the water in the outer cup will behave very differently from that in the center cup. The water in the outer cup will concentrate against the sides of the cup directed away from the disk center and against the rotation direction of the disk. As a consequence, the potential harmfulness of the measured accelerations could not be fully estimated in the current study. It should be noted that these limitations should also be kept in mind when assessing the value of the evidence provided by earlier shaking studies.17 and Caffey18 hypothesized that violent abusive shaking may result in severe head injury in infants and small children. Although much has been learned since then, the current results suggest that more research is needed to properly determine the detailed kinematics of infants during shaking and their effects on the infant's anatomy. Commonly used shaking injury thresholds have recently been called into question for various reasons.19 Many such thresholds have not been properly validated for applicability to infants, and few take into account the very different loading patterns found in shaking versus impacts. Although impacts may cause large impulse transfers by short duration, high-intensity peaks, shaking may transfer just as large or even larger impulses with lower maximum forces, but over longer and repeated cycles. The repetitive loading and constant negative Z-acceleration shown to occur during fierce shaking in the current study may yield clues to understanding the injuries observed in IHI-ST.Approximately 47 years ago Guthkelch


The presented results imply that cochlear implantation of bilaterally hearing-impaired patients over 70 positively influences their cognitive skills.Several studies demonstrated the association of hearing disorders with neurocognitive deficits and dementia disorders, but little is known about the effects of auditory rehabilitation on the cognitive performance of the elderly. Therefore, the research question of the present study was whether cochlear implantation, performed in 21 patients over 70 with bilateral severe hearing impairment, could influence their cognitive skills. The measuring points were before implantation and 12 months after the first cochlear implant (CI) fitting. Evaluation of the working memory (WMI) and processing speed (PSI) was performed using the Wechsler Adult Intelligence Scale 4th edition (WAIS-IV). The audiological assessment included speech perception (SP) in quiet , noise , and self-assessment inventory . Twelve months after the first CI fitting, not only the auditory parameters (SP and OI), but also the WMI and PSI, improved significantly ( According to the WHO, approximately 466 million people worldwide are affected by disabling hearing loss . One-thiHearing disorders contribute to functional and skill decline, and can lead to social isolation, depression, and reduced quality of life ,6. FurthExtensive epidemiological studies have already demonstrated that hearing disorders are associated with neurocognitive deficits and dementia . Mild heDementia affects predominantly, but not exclusively, older people. Dementia is a syndrome manifested by various organic brain disorders ,15, distWorking memory and processing speed strongly correlate with fluid intelligence, which is responsible for abstract reasoning and problem-solving . The fluHearing disorders have only been given a subordinate role in the recent past. Today, almost all types of hearing impairment can be treated. Depending on the severity and localization of hearing impairment, rehabilitation of sensorineural hearing loss ranges from using a digital conventional hearing aid to cochlear implants (CIs). For the auditory rehabilitation of hard-of-hearing people, cochlear implants have been used successfully in various age groups, including the elderly, suggesting that advanced age is not a limitation for CI . The scientific examination of hearing loss and its effects on the elderly is critical for healthy aging. Recent studies demonstrated that hearing impairment has consequences that are more far-reaching than the loss of communication skills. For example, rehabilitation with CIs reduced depression, anxiety, stress, and tinnitus ,30,31,32Based on the link between hearing impairment and a significant increase in cognitive deficits, recent research in the field has focused on studying the association between auditory rehabilitation with CIs and dementia diseases . In the The present work aimed to describe changes in the cognitive performance of bilaterally hearing-impaired patients over 70 who underwent auditory rehabilitation with unilateral CIs. A standardized intelligence test, WAIS-IV, was used to determine cognitive performance  before aThe local ethics committee (permit number EA2/030/13) approved this prospective, non-interventional, and longitudinal study. All investigations were conducted according to the principles expressed in the Declaration of Helsinki. All patients have given their informed written consent. Diagnosis of post-lingual, bilateral, and severe hearing loss with speech perception ≤ 60% in the Freiburg Monosyllabic Test (speech perception in quiet) and with best-fitted hearing aids with sound pressure level (SPL) 65 dB, as previously described German mother tongueAge 70 and aboveUnilateral cochlear implant○Possibility of using general anesthesia○Exclusion of retrocochlear disorder ○Unremarkable cochlear anatomy○Motivation for postoperative audiological rehabilitationMeeting of the clinical criteria for cochlear implantation:Patients of both genders were consecutively included in this study. The following inclusion criteria were used: Diagnosed dementia syndrome or mild cognitive impairment in the medical historySevere visual impairment in the medical historyLost to follow-up On average, our center performs about 135 cochlear implantations annually; about 25% of the patients (33–34 subjects) are over 70 years old. Of them, 65% (21–22 subjects) are severely hearing impaired on both sides. Of these, about 20% (4–5 subjects) will have the second side implanted within a year after the first surgery, and cannot be evaluated further (for the purpose of this particular study). That means that every year, around 17 to 18 patients could be included. However, some do not want to participate in clinical studies; some do not meet the inclusion criteria; and some pass away from reasons unrelated to implantation or are lost to follow-up. In the end, we have about 5–10 patients a year who meet the inclusion criteria and are willing to participate.®  or by Cochlear® . The appointments were scheduled before surgery and twelve months after the first CI fitting   was usedThe Oldenburg Sentence Test (OLSA) was employed to determine the speech perception in noise . The OLSThe audiological assessment was performed one, three, six, and twelve months after the first fitting of the CI. The speech processor was first fitted four weeks after the implantation. Then, as part of the follow-up rehabilitation, the setting was improved weekly by an experienced audiologist and a specialized speech therapist in a face-to-face situation. Thus, with increasing time intervals, twenty therapeutic sessions were completed over 12 months. Each therapy unit consisted of a speech therapy session and an audiological speech processor adaptation. Approximately 90 to a maximum of 120 min were spent per appointment. In addition, no cognitive training and no intermediate intelligence tests were performed during the auditory rehabilitation process.The OI comprises three subcategories: hearing in quiet, hearing with background noise, and sound source localization. The 12 closed questions about everyday situations are rated with points from 1 to 5. The higher the score, the better the subjective hearing .The ADS-L includes 20 items and allows the self-assessment of impairment by depressive symptoms in the last few weeks. The internal consistency (Cronbach’s α) ranges from 0.89 to 0.92; the cutoff value is 23 points . The ADSA validated German version of the WAIS-IV test  was used to assess cognitive abilities. The WAIS-IV is an internationally established, standardized, and validated instrument for measuring age-matched cognitive performance. All subjects were tested before implantation and 12 months after the first CI fitting. In order to avoid learning effects, no cognitive tests were performed in between. The test was carried out in the same order for each subject.The WAIS-IV enables the assessment of the cognitive development status of a person by determining an overall IQ. The scoring allows the calculation of four IQ indicators: speech understanding and perceptual logical thinking for crystalline intelligence, and working memory (WMI) and processing speed (PSI) for fluid intelligence. The individual index values were calculated based on the mandatory subtests connected with the associated tasks. The present study focused on the index processing speed (PSI) and the index working memory (WMI) because of their association with hearing impairments and fluid intelligence described above. The subtests “Coding” and “Symbol Search” were used to determine the PSI, whereas “Digit Span” and “Arithmetic” were used for the WMI ,60. The The raw values recorded were scaled and then converted into age-correlated total values, with normalization to 100 points and a standard deviation of 15 points. This normalization followed a Gaussian distribution; 100 points indicated average intelligence. Deviations up or down indicated above- or below-average intelligence.The test was conducted strictly according to the test procedure manual in a highly standardized manner. The examiner read the instructions out loud. Before commencing each test, the subjects were asked whether they correctly understood the test procedure. Next, the test provided exercises that allowed the determination of whether the test person understood the task. The manual also provided instructions if the exercise was conducted incorrectly or a certain number of tasks would not be completed. Lip-reading was allowed. In addition, the repetition of the task was allowed upon request.Hearing-impaired persons can also use the WAIS-IV. The prerequisite is the use of personal, best-fitted hearing aids on both ears. The test was carried out in a bright, soundproof room by the same investigator under standardized conditions following the WAIS-IV implementation protocol. The internal consistency with the reliability coefficient alpha was α = 0.94 for WMI and alpha α = 0.90 for PSI ,61. Bothsp). Multiple linear regression could not be performed because the test requirements were not met.For the statistical analyses, SPSS version 25.0  was used. The WAIS-IV was evaluated using the original software version 2.1.0 to calculate the scaled scores and the age-related IQ index values. According to a Gaussian distribution, the age-related norm group of the WAIS-IV is defined with an average of 100 IQ points. The results are presented as the mean (MV) ± standard deviation (SD). The level of significance was set at 5%. A two-tailed Wilcoxon signed-rank test was used to compare the scores before and after implantation, as most of the dataset lacked a normal distribution. The effect size was calculated following the recommendations of Cohen for non-parametric tests . CorrelaThe a priori power analysis for calculating the directed difference in WAIS-IV before and after surgery resulted in a sample size of 20 subjects, assuming a normal distribution .Ten female (47.6%) and 11 male (52.4%) subjects were evaluated. The mean age in the study sample was 77.1 ± 5.5 years. There was an average of 39.6 days between the inclusion in the study (and the WAIS-IV test) and implantation. The average duration of hearing impairment was 32.0 ± 22.3 years.p < 0.01). Each ear was tested separately; the opposite ear was masked.Preoperatively, when measured in silence with a masked contralateral ear, SP on the operated ear was 6.0 ± 10.2% (range 0–40%), and that of the contralateral, better-hearing ear was 29.5 ± 20.8% (range 0–60%). Twelve months after the initial CI fitting, the FMT score with CIs and a speech processor was 57.4 ± 22.0%, indicating significant improvement compared to the preoperative baseline value .There was a significant improvement in all domains tested 12 months after the first CI fitting compared to the preoperative baseline value . In addition, none of the patients scored above the critical value of 23 points, which indicated major depression.The mean value of the ADS-L before implantation was 11.3 ± 8.8 points. Twelve months later, the mean ADS-L score was 12.5 ± 10.2. There were no significant differences between the before and after values . In addition, in agreement with earlier studies [p > 0.05).Here, we report for the first time the WAIS-IV IQ index values reflecting the working memory and processing speed of elderly patients with bilateral severe hearing loss before and after unilateral cochlear implantation and auditory rehabilitation. One year after the first CI fitting, we found a significant improvement in the working memory and processing speed  of female to male subjects was balanced. The depression index was low before and remained low after implantation; thus, the possible influence of depressive symptoms on cognitive performance was excluded . AccordiThe measurement of speech perception with the FMT goes beyond pure tone audiometry (PTA). Understanding monosyllabic words in silence (or even sentences in background noise) is a complex hearing situation, and requires cognitive performance . NumerouMoberly et al.  suggesteThe measurement of intelligence is based on the findings of Caroll, Horn, and Cattell, and is known as the CHC model . It paveThe link between hearing rehabilitation using CIs and cognitive performance was already entertained at the beginning of the CI era ,74,75,76More recently, Mosnier et al.  contribuOn the other hand, the WAIS-IV has sufficient sensitivity to determine changes even with an average starting value. We therefore consider that the WAIS-IV offers adequate statistical power to analyze small study cohorts that are common in clinical CI research. In addition, the IQ values in our study had a typical spread and average mean values for both working memory and processing speed, enabling subsequent comparisons with future studies. Nevertheless, impaired hearing function could potentially produce biased results. However, under identical testing conditions, obtaining comparable values would be expected.The cognitive assessment performed during our study was deliberately repeated only one year after the first CI fitting to avoid possible learning effects, which could have occurred if the test was repeated only six months after the first testing session . NeverthVölter et al.  studied Sarant et al.  selectedThe influence of age on cognitive abilities, especially fluid intelligence, has been described many times, and is regarded as a part of the physiological aging process . The preMertens et al.  reportedAlthough Zhan et al.  reportedThe present study determined the effects of a single-sided CI on hearing rehabilitation outcome and cognitive skills in bilaterally hearing-impaired individuals over 70. In addition to improved auditory performance, a significant enhancement of cognitive performance regarding working memory and processing speed was noted. Both working memory and processing speed are essential in speech perception, both in silence and in background noise.