The prevalence of misophonia in a representative population-based survey in Germany.

PURPOSE: Misophonia is a new disorder, currently defined as significant emotional and physiological distress when exposed to certain sounds. Although there is a growing body of literature on the characteristics of the disorder, the prevalence in the general population is still relatively unknown. This study therefore aims at determining the prevalence and symptom severity of misophonia in a large and representative general population sample in Germany. METHODS: To examine the prevalence of misophonic sounds, misophonic reactions and misophonia severity, a cross-sectional population representative survey in Germany has been conducted. Participants (N = 2.522) were questioned retrospectively about misophonic symptoms using the Amsterdam Misophonie Scale - Revised (AMISOS-R). RESULTS: Overall 33.3% reported to be sensitive to at least one specific misophonic sound. Within the total sample, subthreshold symptoms were reported by 21.3%, mild symptoms were reported by 9.9%, moderate to severe symptoms were reported by 2.1%, and severe to extreme symptoms were reported in 0.1% of participants. CONCLUSION: Based on the diverging presentations and prevalence rates of misophonic sounds, reactions and symptoms according to the severity, it seems worthwhile to conceptualize misophonia as a rather continuous spectrum disorder (subthreshold, mild, moderate to severe), still taking into account that an additional categorical diagnostic approach might be necessary to derive a diagnosis in clinical practice.

Misophonia reactions in the general population are correlated with strong emotional reactions to other everyday sensory-emotional experiences.

Misophonic experiences are common in the general population, and they may shed light on everyday emotional reactions to multi-modal stimuli. We performed an online study of a non-clinical sample to understand the extent to which adults who have misophonic reactions are generally reactive to a range of audio-visual emotion-inducing stimuli. We also hypothesized that musicality might be predictive of one's emotional reactions to these stimuli because music is an activity that involves strong connections between sensory processing and meaningful emotional experiences. Participants completed self-report scales of misophonia and musicality. They also watched videos meant to induce misophonia, autonomous sensory meridian response (ASMR) and musical chills, and were asked to click a button whenever they had any emotional reaction to the video. They also rated the emotional valence and arousal of each video. Reactions to misophonia videos were predicted by reactions to ASMR and chills videos, which could indicate that the frequency with which individuals experience emotional responses varies similarly across both negative and positive emotional contexts. Musicality scores were not correlated with measures of misophonia. These findings could reflect a general phenotype of stronger emotional reactivity to meaningful sensory inputs. This article is part of the theme issue 'Sensing and feeling: an integrative approach to sensory processing and emotional experience'.

Beyond sound irritation: cross-cultural evidence on the robustness of the five aspects of misophonic experience measured by the S-Five in a Polish sample.

Misophonia is commonly associated with negative emotional or physiological responses to specific sounds. However, the consensus definition emphasizes that misophonia entails much more than that. Even in cases of subclinical misophonia, where individuals do not meet the disorder criteria, the experience can still be burdensome, despite not currently causing significant distress or impairment. The S-Five is a psychometric tool for comprehensive assessment of five aspects of misophonic experience: internalizing, externalizing, impact, threat, and outburst, and includes S-Five-T section to evaluate feelings evoked by triggering sounds and their intensity. We examined whether the five-factor structure developed in the UK could be replicated in a Polish sample, including individuals with and without self-identified misophonia. The Polish version of the S-Five was translated and tested on 288 Polish-speaking individuals. Comprehensive psychometric evaluation, including factor structure, measurement invariance, test-retest reliability, internal consistency, and concurrent validity evaluations, was conducted on the translated scale. Exploratory factor analysis suggested similar structure to the original English study, while bootstrap exploratory graph analysis showed the factor structure to be reproducible in other samples. The scale was found to be bias free with respect to gender, internally consistent and stable in time, and evidence of validity was provided using MisoQuest and Misophonia Questionnaire. These results offer support for the cross-cultural stability of the five factors and provide preliminary evidence for the suitability of the Polish version for clinical and research purposes. The study also investigated five facets of misophonia, triggering sounds, emotional responses, and their associations with symptoms of psychopathology across various cultures. It underscores the central role of anger, distress, and panic, while also highlighting the mixed role of irritation and disgust in misophonia across different cultural contexts. Mouth sounds evoked the most pronounced reactions compared to other repetitive sounds, although there were discernible cultural differences in the nature and intensity of reactions to various trigger sounds. These findings hold significant implications for future research and underscore the importance of considering cultural nuances in both research and the clinical management of misophonia.

Association between Chronic Misophonia-Induced Stress and Gastrointestinal Pathology in Children-A Hypothesis.

Misophonia is a neurophysiological disorder with behavioral implications, is complex and multifactorial in origin, and is characterized by an atypical and disproportionate emotional response to specific sounds or associated visual stimuli. Triggers include human-generated sounds, mainly sounds related to feeding and breathing processes, and repetitive mechanical sounds. In response to the triggering stimulus, the patient experiences immediate, high-intensity, disproportionate physical and emotional reactions that affect their quality of life and social functioning. The symptoms of misophonia can occur at any age, but onset in childhood or adolescence is most common. Affected children live in a constant state of anxiety, suffer continuous physical and emotional discomfort, and are thus exposed to significant chronic stress. Chronic stress, especially during childhood, has consequences on the main biological systems through the dysregulation of the hypothalamic-pituitary-adrenal axis, including the gastrointestinal tract. Here, we provide arguments for a positive correlation between misophonic pathology and gastrointestinal symptoms, and this hypothesis may be the starting point for further longitudinal studies that could investigate the correlations between these childhood vulnerabilities caused by misophonia and their effect on the gastrointestinal system. Further research to study this hypothesis is essential to ensure correct and timely diagnosis and optimal psychological and pharmacological support.

Structural Variants and Implicated Processes Associated with Familial Tourette Syndrome.

Gilles de la Tourette syndrome (GTS) is a neurodevelopmental psychiatric disorder with complex and elusive etiology with a significant role of genetic factors. The aim of this study was to identify structural variants that could be associated with familial GTS. The study group comprised 17 multiplex families with 80 patients. Structural variants were identified from whole-genome sequencing data and followed by co-segregation and bioinformatic analyses. The localization of these variants was used to select candidate genes and create gene sets, which were subsequently processed in gene ontology and pathway enrichment analysis. Seventy putative pathogenic variants shared among affected individuals within one family but not present in the control group were identified. Only four private or rare deletions were exonic in LDLRAD4, B2M, USH2A, and ZNF765 genes. Notably, the USH2A gene is involved in cochlear development and sensory perception of sound, a process that was associated previously with familial GTS. In addition, two rare variants and three not present in the control group were co-segregating with the disease in two families, and uncommon insertions in GOLM1 and DISC1 were co-segregating in three families each. Enrichment analysis showed that identified structural variants affected synaptic vesicle endocytosis, cell leading-edge organization, and signaling for neurite outgrowth. The results further support the involvement of the regulation of neurotransmission, neuronal migration, and sound-sensing in GTS.

Preliminary validation of the Norwegian version of the Berlin Misophonia Questionnaire Revised (BMQ-R-NOR).

OBJECTIVE: To perform a psychometric evaluation of a Norwegian version of the Berlin Misophonia Questionnaire Revised (BMQ-R-NOR). DESIGN: Participants completed online versions of the self-report questionnaire BMQ-R-NOR on two occasions and MQ-NOR on one occasion. Convergent validity was assessed through Spearman's correlation between BMQ-R-NOR and MQ-NOR. Internal consistency was evaluated with McDonald's omega and Cronbach's alpha. Test-retest reliability was evaluated using Cohen's weighted kappa and intraclass correlation. STUDY SAMPLE: 82 participants with self-reported misophonia took part in the study at T1, and 53 of these participated at T2. However, only 41 of them were included in the test-retest analyses due to 12 participants being in treatment between T1 and T2. RESULTS: Subscales from the BMQ-R-NOR and MQ-NOR were significantly positively correlated, indicating evidence of convergent validity (rs = 0.22*-0.74**). The BMQ-R-NOR showed overall good internal consistency (omega = 0.72-0.93; alpha = 0.70-0.93) and satisfactory test-retest reliability (ICC = 0.35-0.92). CONCLUSION: The psychometric properties of the BMQ-R-NOR are considered satisfactory. However, it is advised to exercise caution when using it until further comprehensive validation studies are conducted to ensure robustness and reliability in clinical practice.

The mediating role of anxiety in the relationship between misophonia and quality of life: findings from the validated Turkish version of MisoQuest.

Introduction: Misophonia is a disorder characterized by decreased tolerance to certain sounds or their associated stimuli, and many measurement tools have been developed for its diagnosis and evaluation. The aims of the current study were to develop the Turkish version of MisoQuest, a fully validated misophonia questionnaire, to evaluate the relationships between misophonia, anxiety, and quality of life, and to examine the mediating role of anxiety in the relationship between misophonia and quality of life. Methods: The reliability of the Turkish version of MisoQuest was conducted using data from 548 participants (Mean age = 28.06 ± 9.36). Then, the relationships between misophonia, anxiety, and quality of life were evaluated in a separate sample of 117 participants (Mean age = 25.50 ± 6.31) using the State-Trait Anxiety Inventory (STAI) and the Short Form 36 (SF-36) questionnaire. Results: The results showed that the Turkish version of MisoQuest has good psychometric properties. Close-to-moderate positive correlations were found between misophonia and anxiety, and weak negative correlations were found between misophonia and quality of life. Anxiety mediated the relationships between misophonia and quality of life. Discussion: These results emphasize that misophonia may be an important problem affecting people's quality of life and reveal the mediating role of anxiety on this effect.

Estimation of Prevalence of Misophonia Among High School Students in India.

Objective: Misophonia, an intriguing psychological disorder is characterized by intense emotional responses to specific sounds produced by others, has gained prominence for its distinct attributes and profound impact on individuals' emotional and psychological well-being. This study addresses the scarcity of research on misophonia's prevalence and severity among high school students, aiming to shed light on the unique challenges faced by this demographic in India. Methods: The study enrolled 597 high school students, including 269 females and 328 males, aged 14 to 16, with no history of psychological or otological problems or medication use. The Misophonia Assessment Questionnaire questionnaire, consisting of 21 questions with a 4-point Likert scale response, assessed emotional and behavioral reactions to sensitive sounds. Participants' scores categorized them as Sub-clinical, Mild, Moderate, or Severe misophonia. Results: The prevalence of misophonia was 34.67% among high school students, with 52.65% categorized as Mild, 45.41% as Moderate, and 1.93% as severe misophonia. A comparison with a similar study on college students in India revealed a higher prevalence of misophonia among high school students. This discrepancy may relate to adolescents' vulnerable psychological states, marked by limited emotional regulation and significant life transitions. Conclusions: This study significantly contributes to the evolving understanding of misophonia by spotlighting its prevalence and severity among high school students in India. The findings underscore the necessity of recognizing and addressing misophonia's impact during adolescence, a crucial developmental phase.

Family Accommodation in Children and Adolescents With Misophonia.

Family accommodation (e.g., reassurance, modifying routines, assisting avoidance) has not been explored among youth with misophonia but may have important clinical and intervention implications. We examined family accommodation in 102 children and adolescents with interview-confirmed misophonia and compared its frequency and content to family accommodation in 95 children and adolescents with anxiety disorders. Findings showed that family accommodation was ubiquitous in pediatric misophonia and may be even more frequent than in youth with anxiety disorders. Assisting the child, participating in misophonia-related behaviors, and modifying family routines were endorsed by more than 70% of parents of children with misophonia. Further, compared to parents of children with anxiety disorders, parents of children with misophonia more frequently reported child distress and anger when they did not accommodate. Family accommodation was moderately to strongly associated with misophonia severity even when accounting for co-occurring internalizing and externalizing symptoms and sociodemographic factors. This first study of family accommodation in pediatric misophonia suggests accommodation may be an important clinical feature. A notable study limitation is that the measure of misophonia did not delineate between adaptive versus maladaptive accommodations. Excessive and maladaptive accommodation may be one potential candidate to target in interventions when considered within a broader treatment plan. Importantly, adaptive accommodations should also be considered in day-to-day management if they improve functioning and quality of life.

Clinical characteristics of treatment-seeking youth with misophonia.

OBJECTIVE: Misophonia is a psychiatric condition characterized by strong emotional and/or behavioral responses to auditory stimuli, leading to distress and functional impairment. Despite previous attempts to define and categorize this condition, misophonia is not currently included in the Diagnostic and Statistical Manual of Mental Disorders or International Classification of Diseases. The lack of formal diagnostic consensus presents challenges for research aimed at assessing and treating this clinical presentation. METHODS: The current study presents clinical characteristics of youth (N = 47) with misophonia in the largest treatment-seeking sample to date. We examined demographic characteristics of the sample, frequency of comorbid disorders, frequency of specific misophonia symptoms (i.e., triggers, emotional and behavioral responses, and impairments), and caregiver-child symptom agreement. Misophonia symptoms were evaluated using a multimodal assessment including clinician, youth, and caregiver reports on empirically established misophonia measures, and concordance among measures was assessed. RESULTS: Youth seeking treatment for misophonia presented with marked misophonia symptoms and an array of comorbid conditions. Youth and caregivers identified various triggers of misophonia symptoms (e.g., chewing sounds, breathing sounds), as well as a wide range of emotional (e.g., anger, annoyance, disgust) and behavioral (e.g., aggression, avoidance) responses to triggers. Youth and caregivers exhibited high agreement on misophonia triggers but lower agreement on symptom severity and associated impairment. Compared to younger children (aged 8-13), older children (aged 14+) appeared to report symptom severity and associated impairment more reliably. CONCLUSION: Misophonia is a heterogenous and impairing clinical condition that warrants future investigation and evidence-based treatment development.

An Automated Online Measure for Misophonia: The Sussex Misophonia Scale for Adults.

Misophonia is a sound sensitivity disorder characterized by a strong aversion to specific sounds (e.g., chewing). Here we present the Sussex Misophonia Scale for Adults (SMS-Adult), within an online open-access portal, with automated scoring and results that can be shared ethically with users and professionals. Receiver operator characteristics show our questionnaire to be "excellent" and "good-to-excellent" at classifying misophonia, both when dividing our n = 501 adult participants by recruitment stream (self-declared misophonics vs. general population), and again when dividing them with by a prior measure of misophonia (as misophonics vs. non-misophonics). Factor analyses identified a five-factor structure in our 39 Likert-type items, and these were Feelings/Isolation, Life consequences, Intersocial reactivity, Avoidance/Repulsion, and Pain. Our measure also elicits misophonia triggers, each rated for their commonness in misophonia. We offer our open-access online tool for wider use (www.misophonia-hub.org), embedded within a well-stocked library of resources for misophonics, researchers, and clinicians.

Psychometric Evaluation and Misophonic Experience in a Portuguese-Speaking Sample.

Misophonia, a disorder characterised by an extreme sensitivity to certain sounds, is increasingly being studied in cross-cultural settings. The S-Five scale is a multidimensional psychometric tool initially developed to measure the severity of misophonia in English-speaking populations. The scale has been validated in several languages, and the present study aimed to validate the European Portuguese S-Five scale in a Portuguese-speaking sample. The scale was translated into Portuguese using a forward-backwards translation method. The psychometric properties of the S-Five scale were evaluated in a sample of 491 Portuguese-speaking adults. Confirmatory factor analysis supported a five-factor structure consistent with previous versions of the S-Five scale. The five factors were as follows: (1) internalising appraisals, (2) externalising appraisals, (3) perceived threat and avoidance behaviour, (4) outbursts, and (5) impact on functioning. The satisfactory psychometric properties of the S-Five scale further indicated its cross-cultural stability. As a psychometrically robust tool, the S-Five can measure misophonia in Portuguese-speaking populations, allowing future studies to explore and compare misophonia in this population.

An experimental examination of neurostimulation and cognitive restructuring as potential components for Misophonia interventions.

Misophonia is a disorder of decreased tolerance to certain aversive, repetitive common sounds, or to stimuli associated with these sounds. Two matched groups of adults (29 participants with misophonia and 30 clinical controls with high emotion dysregulation) received inhibitory neurostimulation (1 Hz) over a personalized medial prefrontal cortex (mPFC) target functionally connected to the left insula; excitatory neurostimulation (10 Hz) over a personalized dorsolateral PFC (dlPFC) target; and sham stimulation over either target. Stimulations were applied while participants were either listening or cognitively downregulating emotions associated with personalized aversive, misophonic, or neutral sounds. Subjective units of distress (SUDS) and psychophysiological measurements (e.g., skin conductance response [SCR] and level [SCL]) were collected. Compared to controls, participants with misophonia reported higher distress (∆SUDS = 1.91-1.93, ps < 0.001) when listening to and when downregulating misophonic distress. Both types of neurostimulation reduced distress significantly more than sham, with excitatory rTMS providing the most benefit (Cohen's dSUDS = 0.53; dSCL = 0.14). Excitatory rTMS also enhanced the regulation of emotions associated with misophonic sounds in both groups when measured by SUDS (dcontrol = 1.28; dMisophonia = 0.94), and in the misophonia group alone when measured with SCL (d = 0.20). Both types of neurostimulation were well tolerated. Engaging in cognitive restructuring enhanced with high-frequency neurostimulation led to the lowest misophonic distress, highlighting the best path forward for misophonia interventions.

Misophonia matters: A case study of the role of brain imaging in debates over new diagnoses.

Misophonia has gained attention in scientific circles that utilise brain imaging to validate diagnoses. The condition is promoted as not merely a symptom of other psychiatric diagnoses but as a discrete clinical entity. We illustrate the social construction of the diagnostic category of misophonia through examining prominent claims in research studies that use brain imaging to substantiate the diagnosis. We show that brain images are insufficient to establish the 'brain basis for misophonia' due to both technical and logical limitations of imaging data. Often misunderstood as providing direct access to the matter of the body, brain images are mediated and manipulated numerical data (Joyce, 2005, Social Studies of Science 35(3), p. 437). Interpretations of brain scans are further shaped by social expectations and attributes considered salient to the data. Causal inferences drawn from these studies are problematic because 'misophonics' are clinically pre-diagnosed before participating. We argue that imaging cannot replace the social process of diagnosis in the case of misophonia, nor validate diagnostic measures or otherwise substantiate the condition. More broadly, we highlight both the cultural authority and inherent limitations of brain imaging in the social construction of contested diagnoses while also illustrating its role in the disaggregation of symptoms into new diagnoses.

Auditory cortical functioning in individuals with misophonia: an electrophysiological investigation.

PURPOSE: Misophonia is characterized by a reduced tolerance for specific sound triggers. This aspect has been relatively underexplored in audiology, with limited research from the audiological angle. Our primary objective is to compare the auditory late latency response (ALLR) findings between individuals with misophonia and those without it. METHODS: A study compared individuals with significant misophonia to a healthy control group. Thirty misophonia participants were categorized into mild and moderate-to-severe groups based on their Amsterdam Misophonia Scale scores. The latency and amplitude of auditory response peaks were analyzed across the groups using the ALLR. Statistical tests included Shapiro-Wilk for data normality, one-way ANOVA for group differences, and Bonferroni post hoc analysis for detailed variation sources. RESULTS: The result showed a significant difference in latency of P1 and N1 peaks (p < 0.05) of ALLR between the groups in both ears. This suggests a deficit in auditory processing at the cortical level in individuals with misophonia. CONCLUSION: Our study substantiates the potential utility of the ALLR as a valuable instrument for evaluating misophonia, particularly from the audiological standpoint.

Normal linear and non-linear cochlear mechanisms and efferent system functioning in individuals with misophonia.

BACKGROUND: Misophonia, a condition characterized by heightened sensitivity and strong emotional reactions to specific sounds, has sparked considerable interest and debate regarding its underlying auditory mechanisms. The study aimed to understand the auditory underpinnings of two such potential inner ear systems, non-linear and linear outer hair cell functioning along with auditory efferent functioning in individuals with misophonia. METHODS: 40 ears with misophonia (20 participants) and 37 ears without misophonia (20 participants), both having normal hearing sensitivity were included in this study. Transient evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) were obtained in two conditions (with and without contralateral noise). RESULTS: Results of independent-samples t-test showed no statistically significant difference (p > 0.05) in the absolute amplitudes of both TEOAEs and DPOAEs between the individuals with and without misophonia. There was no statistically significant difference (p > 0.05) observed in the magnitude of suppression amplitude between the two groups for in both TEOAEs and DPOAEs between individuals with and without misophonia. CONCLUSION: These results suggest that the cochlear and efferent auditory underpinnings examined in this study may not be major contributors to the development or manifestation of misophonia.

Alterations in attentional processing in youth with misophonia: A phenotypical cross-comparison with anxiety patients.

BACKGROUND: Misophonia is a complex condition characterized by extreme emotional distress in response to specific sounds or specific visual stimuli. Despite a growing body of clinical and neuroscientific literature, the etiology of this condition remains unclear. Hyperarousal, that is, a state of heightened alertness and disinhibition, as a core feature of misophonia is supported by behavioral and neuroimaging literature and might represent a viable clinical target for the development of both behavioral and pharmacological interventions. The aim of this study was to investigate how hyperarousal might be linked to neurocognitive processes associated with vigilance and stimulus discrimination in youth with misophonia. METHODS: We compared 72 children and adolescents with misophonia (13.74 ± 2.44 years) (64 % female) and 89 children and adolescents with anxiety (12.35 ± 2.57 years) (58.4 % female) on behavioral and signal detection performance of the immediate memory task (IMT). Anxiety patients were used as a clinical control group to distinguish attentional processes specific for misophonia. RESULTS: Both groups demonstrated similar behavioral performance, including response rate and reaction time. However, misophonia was associated with elevated stimulus discrimination (d prime), which in turn was positively correlated with the severity of misophonia trigger reports. CONCLUSIONS: Our findings are in line with previous cognitive and neuroimaging studies, and support an arousal-based model of misophonia, where individuals with misophonia experience a state of heightened vigilance, being more aware of stimuli in the environment. Our findings provide a neurocognitive basis for future study of neurochemical imaging that might further progress towards clinical targets.

Mimicry in misophonia: A large-scale survey of prevalence and relationship with trigger sounds.

BACKGROUND: Misophonia is often referred to as a disorder that is characterized by excessive negative emotional responses, including anger and anxiety, to "trigger sounds" which are typically day-to-day sounds, such as those generated from people eating, chewing, and breathing. Misophonia (literally "hatred of sounds") has commonly been understood within an auditory processing framework where sounds cause distress due to aberrant processing in the auditory and emotional systems of the brain. However, a recent proposal suggests that it is the perceived action (e.g., mouth movement in eating/chewing sounds as triggers) of the trigger person, and not the sounds per se, that drives the distress in misophonia. Since observation or listening to sounds of actions of others are known to prompt mimicry in perceivers, we hypothesized that mimicking the action of the trigger person may be prevalent in misophonia. Apart from a few case studies and anecdotal information, a relation between mimicking and misophonia has not been systematically evaluated. METHOD: In this work, we addressed this limitation by collecting data on misophonia symptoms and mimicry behavior using online questionnaires from 676 participants. RESULTS: Analysis of these data shows that (i) more than 45% of individuals with misophonia reported mimicry, indicating its wide prevalence, (ii) the tendency to mimic varies in direct proportion to misophonia severity, (iii) compared to other human and environmental sounds, trigger sounds of eating and chewing are more likely to trigger mimicking, and (iv) the act of mimicking provides some degree of relief from distress to people with misophonia. CONCLUSION: This study shows prevalence of mimicry and its relation to misophonia severity and trigger types. The theoretical framework of misophonia needs to incorporate the phenomenon of mimicry and its effect on management of misophonia distress.

Corrigendum: A longitudinal investigation of quality of life and negative emotions in misophonia.

[This corrects the article DOI: 10.3389/fnins.2022.900474.].

The Impact of Mental Health Symptoms in Children With Tinnitus and Misophonia: A Multi-disciplinary Approach.

Tinnitus and misophonia are important "sound annoyance" disorders in pediatric otolaryngology and audiology practices. There is scant published literature to suggest increased anxiety and depression symptoms in these disorders. This study aimed at assessing the clinical characteristics of these 2 disorders and their prevalence in mental health-related symptoms in a 2-year retrospective chart review of a multi-disciplinary (otolaryngology, audiology, and psychology) clinic cohort. Analyses were based on 54 (tinnitus = 33 and misophonia = 21) children consisting of 19 males and 35 females with a mean age (standard deviation) of 14.3 (3.0) years. The entire cohort was negatively affected by diagnosis-based symptom severity instruments as assessed by Tinnitus Functional Index and Amsterdam Misophonia Scale. Both subgroups exhibited elevated anxiety and depression symptoms in psychometric instruments as assessed by Screen for Child Anxiety Related Emotional Disorders and Short Mood and Feelings Questionnaire. Evidence-based management of these disorders is lacking, and clinical trials are needed.