Adverse vocal behavior voice disorders are the most common type of voice disorder in children. They cause a significant reduction in voice quality due to hoarseness, harsh voice or difficulty vocalizing, leading to difficulties in expression and communication.
Compared with children with healthy voices, children with voice disorders are more likely to receive negative evaluations from their parents or peers, which negatively affects children’s physical condition and mental health, educational development, and self-image [ 1].
Compared with adults, children have lower elastin content in the vocal folds [2, 3] and have not yet formed a stable structure, making them more prone to voice disorders due to adverse vocal behaviors such as shouting, crying and excessive use of voice [4].
Voice disorders may include vocal cord nodules, vocal cord polyps, and chronic laryngitis, including intrachordal edema associated with laryngitis, which may be considered at different stages of development of the same disease [5]. Additionally, children’s low levels of self-control, limited understanding, and poor coordination increase the difficulty of treatment.
The purpose of this review is to raise awareness among clinicians and the public about the adverse effects of behavioral voice disorders in children, to highlight the importance of changing these behaviors in children, and hope that it will contribute to the direction and outcomes. Objectives of research on voice disorders due to adverse vocal behavior in children.
| Materials and methods |
> Literature review
A search was conducted in online databases including Google Scholar, PubMed, and CNKI. Search terms included “vocal nodules,” “vocal cord polyp,” “voice disorder,” “voice abuse,” “voice misuse,” “pediatrics,” and “children,” with the appropriate boolean operators.
A total of 315 results were collected in an initial PubMed search. All articles from 2000 to 2022 written in English or Chinese were screened by the authors.
Duplicate articles, those related only to adults or on malignant lesions of the vocal folds were excluded, resulting in 196 articles of interest. References and relevant books were also consulted.
> Etiology and pathogenesis
The immediate causes of adverse vocal behavior voice disorders in children are abuse and misuse of the voice. Voice abuse includes prolonged screaming and crying, and voice misuse means children speak at an incorrect tone or volume [6]. As for the precipitating factor of voice disorders due to adverse vocal behavior, there are two factors: the unique structures of the larynx and vocal cords of children and the personality traits of the child.
First, children’s vocal folds lack the three-layer structure of adults, and vocal folds lack elastin and elastic fibers in their lamina propria [7–9]. Furthermore, laryngeal muscle control is not yet fully developed in children, and they have greater subglottic pressure when speaking than adults [10]. This, combined with poor vocal behavior for a time, can lead to an alteration of the epithelial structure of the vocal folds, a breakdown in the junctions of the epithelial cells and a reduction in the protection of the lower mucosa by the epithelial barrier of the vocal folds. vocal cords, making them more susceptible to injury [11, 12].
Second, Lee and colleagues [13] found that children with vocal fold nodules have significantly lower levels of self-control than normal children in terms of emotional management, behavioral management, or cognition, leading to more impulsive emotions. and uncontrollable and to an increase in the probability of developing undesirable vocal behaviors in unexpected situations.
| Associated causal factors |
> Gender
Differences in verbal behavior between boys and girls are mainly due to differences in emotional expression. Currently, there are three main theoretical models to explain differences in emotional expression which are biological, social developmental and social constructionist [14, 15].
Biological theory suggests that boys have less inhibitory control due to hormones, which can cause boys to be more likely to express negative emotions (anger), in addition to the fact that boys develop their larynx more quickly than girls. , so girls’ voices are more stable than boys’ voices at puberty [16, 17].
Social development theory postulates that children learn behaviors consistent with gender roles through cognitive learning, socialization, and experience [18], meaning that boys engage in more rough play, while girls enjoy rough play. calm cooperatives. This is also consistent with the findings of Carding and colleagues [19] from a cross-sectional study of 8-year-old children in which boys had a significantly higher prevalence rate of voice disorders than girls, possibly due to the excessive volume required to social and physical activities in adolescence [20].
Social construction theory suggests that emotional expression is influenced by specific contexts and social expectations of men and women, with boys expected to display less kind emotions and encouraged to express more external emotions such as anger and disgust.
Recent studies have also shown a predominance of vocal disorders in boys during childhood, possibly due to generally extroverted and impulsive personality and psychological characteristics of prepubertal boys, who are more likely to exhibit inappropriate vocal behavior [21, 22].
> Family atmosphere
Tuzuner and colleagues [23] compared the home environment of normal children and children with voice disorders due to adverse vocal behavior and found that the frequency of use of higher voice decibel levels was higher in children with younger siblings and that the youngest or oldest child in the family had the highest risk of acquiring voice disorders due to adverse vocal behavior.
A Japanese cross-sectional survey of children with hoarseness found a negative association between participation in family conversations and voice quality, suggesting that children’s poor vocal behavior is more likely to occur in conversations with family members. of the family [24].
> Psychological and behavioral characteristics
Vocal fold nodules and vocal fold polyps are the most prevalent adverse vocal behavioral voice disorders in children. The results of a previous psychological investigation of children with vocal fold nodules revealed that children with vocal fold nodules were characterized as more active, extraverted, and inattentive [22], and Reis-Rego and colleagues [25] first found an association between vocal cord nodules and ADHD.
> Excessive participation in extracurricular activities or interest classes
One study found a significant increase in the prevalence of hoarseness in children after extracurricular activities such as summer camps [26], which may be explained by the fact that they often shout during extracurricular activities.
A recent study of a Spanish children’s choir [27] reported that the reason why children in this choir had a lower prevalence of voice disorders compared to other children was due to the choir’s persistent focus on vocal hygiene. voice and the appropriate use of children’s voices. This suggests that although participation in extracurricular activities may increase the prevalence of voice disorders, it can still effectively prevent the occurrence of voice disorders due to poor vocal behavior by paying attention to voice protection.
| Diagnosis |
>> Subjective evaluation
> Evaluation by others
Many questionnaires and scales have been developed in recent years to assess the severity of voice disorders and their impact on children’s quality of life, mostly completed by parents, such as the Voice Disability Index in Pediatrics (pVHI) [28] and Pediatric Voice-Related Quality of Life (PVRQOL) [29].
The pVHI can be used to monitor emotional, physical, and functional changes in children after surgery and voice training and has been used in different countries with high internal consistency (Cronbach’s α range of 0.71–0. .95) [30–32.
The PVRQOL is a valid and reliable scale that can be used as a screening test for children with or without voice disorders and has now been translated into other languages, both of which have good internal consistency (Cronbach’s α range of 0.81–0. .90), validity (r=0.72–0.95) and reliability [33–35]; pVHI was strongly correlated with PVRQOL [36], but there are differences between parents’ and children’s perspectives on voice disorders.
Cohen and Wynne [37] showed that parents are more inclined to overestimate the impact of voice disorders on their children, so Ricci-Maccarini and colleagues [38, 39] developed the Children’s Voice Impairment Index. -10 (CVHI-10) evaluated from the perspective of both the child and the parents. A recent study by Yağcıoğlu and colleagues [40] developed the Teacher-Reported Pediatric Voice Handicap Index (TRPVHI) assessed from the teacher’s perspective.
The combination of the TRPVHI and other subjective instruments may offer a more comprehensive assessment of the physical, functional, and emotional effects of voice disorders in children and provide more references for future research on voice disorders in children.
> Stroboscopic laryngoscope
The advantage of a stroboscopic laryngoscope as a first examination to evaluate voice disorders is that it can evaluate the vibration, symmetry and closure of the vocal folds using mucosal waves [41] and detect micro lesions of the vocal fold mucosa.
However, for children who cannot fully cooperate with laryngoscopy like adults, Zacharias et al [42] recommend high-speed video endoscopy (HSV), and [43] used HSV to compare vocal fold movement patterns. in normal children and in children with vocal fold lesions (nodules, polyps, cysts) and found that HSV could observe true vocal fold vibration cycles and more subtle changes in vocal fold mucosal waves [44].
Deliyski and colleagues [45] found that HSV with frame rates above 4000 fps was much more efficient in evaluating vocal fold mucosal wave motion. However, the HSV analysis process is quite time-consuming and requires a large amount of data storage space and an advanced computer, making it so expensive that it is not widely used in clinical practice [46].
Over the past decade, video strobochymography (VSK) has become a cheaper and more convenient alternative to HSV. It is feasible for the examination of vocal cord lesions in children [47].
> Ultrasound of the larynx in children
In cases where children cannot tolerate laryngoscopy, ultrasound of the larynx can provide information about vocal fold pathology and vocal fold motility, although the mucosal waves themselves cannot be obtained, but They are useful in evaluating vocal fold movement or asymmetry in anatomy.
Lee et al [48] found that ultrasonography of the larynx was the most effective way to detect postoperative vocal cord paralysis in newborns and young children.
Ongkasuwan and colleagues [49] found that laryngeal ultrasound had a sensitivity of 100% and a specificity of 87% for vocal fold nodules, allowing screening tests for vocal fold nodules. However, this approach could not be used to differentiate other vocal fold lesions, such as vocal fold polyps, vocal fold cysts, and laryngeal papilloma.
> Optical coherence tomography
In recent years, optical coherence tomography (OCT) has been used to image the laryngeal mucosa, cricoid cartilage, and alveoli in children [50-52].
Benboujja and Hartnick [53] found that OCT could clearly present hyperkeratotic areas of vocal fold nodules and show well-defined oval vocal fold cysts within the lamina propria, which helped differentiate vocal fold nodules from cysts. of the vocal folds, and OCT could also be used to detect and quantify the early stages of Reinke’s edema.
Their later findings used OCT to show the microscopic anatomy of the vocal folds at different ages and found that OCT was useful for examining the superficial layers of the lamina propria of the vocal folds in newborns [54].
| Objective evaluation |
> Acoustic sound analysis
Acoustic sound analysis can be divided into linear analysis and nonlinear analysis. Linear analysis mainly includes fundamental frequency (F0), irregularities, waves and NHR.
The vocal folds can produce speech signals with approximately regular movements; Therefore, most scientists agree that linear acoustic analysis of voice can be well applied to children [55, 56].
Bilal and colleagues [57] were the first to use computer-assisted processing techniques to calculate the size of vocal nodules in children and compared objective acoustic values with subjective evaluation, revealing that the fundamental frequency (F0) was strongly influenced by the width of the nodule.
Regarding vocal folds with lesions, since the voice signal produced is non-periodic, Meredith et al [58] suggested analyzing non-linear voice acoustic values among children with voice disorders.
Recently, Esen and colleagues [59] applied cepstral analysis to speech signals and found that cepstral peak prominence (CPP) provided better distinction between children with normal and dysphonic voices, with Demirci and colleagues [60] later finding that the CPP of boys decreases over the years, while the change is not evident in girls. This suggests that more research should be conducted to examine the acoustics of children’s voices, and the use of acoustic analysis in clinical practice is also worthy of exploration.
> Electroglottography
Electroglottography (EGG) is a non-invasive method of monitoring vocal fold vibration by measuring the change in neck resistance at the level of the vocal folds [61].
In a recent study, Patel and Ternström [62] compared the EGG of 26 adults and 22 children and found that the children’s EGG did not have a characteristic inflection point, suggesting that the EGG can distinguish well between adult and adult voices. children’s voices. Szklanny and colleagues [63] found that 95% of children with vocal fold nodules had a characteristic bilateral peak on closed-phase electroglottogram, providing new rationale for differentiating vocal fold cysts from vocal fold nodules. vowels; This technique is more effective than acoustic value analysis for the diagnosis of vocal cord nodules.
| Treatment |
> Conservative treatment
There is no comprehensive clinical guideline or consensus on the treatment of voice disorders associated with adverse vocal behaviors in children.
Since the main causes of voice disorders in children and the histological characteristics of the vocal cords of children are different from those of adults, voice therapy is particularly important and has become the first choice for the treatment of voice disorders associated with adverse vocal behaviors in children, with the aim of reducing poor pronunciation in children and restoring normal vocal fold structure to achieve voice improvement. However, children’s poor self-control and ability to understand and perform at different ages varies greatly, and their personality characteristics, such as extroversion and inattention, make it difficult to implement voice training for children.
Voice training is divided into direct voice therapy and indirect voice therapy. Direct therapy focuses on altering vocal biomechanisms, including vocal tract semi-occlusive exercises, resonant voice, vocal function exercises, and laryngeal massage [64].
Although indirect treatment involves voice hygiene, including management of the larynx through behavioral changes without actual vocal training, indirect treatment may also include psychological counseling that can reduce behaviors such as screaming and crying, which could damage sound. [65].
Comparing children with vocal fold nodules who received indirect voice treatment and direct voice training, Hartnick and colleagues [66] found that both approaches effectively improved the quality of life of children with vocal fold nodules.
Currently, the most widely used voice training method for children with voice disorders is semi-closed vocal tract training, which includes lip trills, straw phonation training, and water resistance training.
Semi-closed vocal tract training is effective not only in improving the child’s subjective experience and objective acoustic evaluation [67, 68] but also in reducing nodule size [69].
Hseu and colleagues [70] recently tested remote voice training for children with vocal fold nodules and found that it can also improve the severity and quality of life of children with hoarseness, so they recommended remote voice training as an alternative treatment.
A systematic review by Feinstein and Abbott [65] can be referenced for a current discussion on voice training modalities and sessions for children.
Recently, remote voice training with apps, video games, and other instruments has also been shown to be a viable technique for voice training [71, 72]. This shows that more clinical studies are needed to explore the best voice training program for children with voice disorders.
| Factors influencing the effectiveness of voice training for children |
> Adhesion
The results of voice training are closely related to children’s adherence. Aside from the many factors that influence adherence in adults, the pediatric age group faces some unique challenges, including the role of family (and its dysfunction) and adolescent variations.
The adherence of pediatric patients with chronic diseases is more complex than that of adult patients. Currently, there is no consensus on methods to predict adherence to voice training in children.
Based on the results of current studies related to adherence in the treatment of chronic diseases in children, it appears that one of the scales and questionnaires used to predict and evaluate adherence in children still has the potential to be successfully applied in the training of the voice in children.
Older children are more likely to participate in and benefit from voice training [64, 66], and some experts recommend voice training for children over 7 years of age [73] who have voice disorders due to adherence. relatively high among this age group.
Ebersole and colleagues [74] found that patient adherence was closely associated with the patient’s subjective assessment of their voice disorder, with VHI-10 scores ≤ 9 or V-RQOL scores >40 being important threshold points for predicting risk. non-adherence.
Hseu and colleagues [64] also concluded that the higher the overall CAPE-V score, the greater the likelihood that the child will receive voice training. Other factors that affected adherence were lack of interest, low recognition of voice therapy, excessive cost, and transportation [75].
> Family participation
According to Sonbay and colleagues [95], voice training is most effective when the mother practices with the child, and Kollbrunner and Seifert [96] believed that reducing conflict within the entire family was also important, so they involved to parents of children with vocal nodules in two to four classes to facilitate parent-child conversations and place the child in a more comfortable home environment. This approach had a positive therapeutic effect on children with voice disorders. King and colleagues developed an interactive video game [97] to motivate children with voice disorders in voice training, and the video game assisted the child in practicing at home, thus increasing family participation and effectiveness.
> Child characteristics
An extroverted and distracted personality is not only a risk factor for behavioral voice disorders, but also affects the effectiveness of voice training. Furthermore, a poor ability to self-regulate behavior and emotions can impair the effectiveness of voice training.
Traditional voice training [13], which focuses on keeping children silent or preventing them from shouting, is not very realistic for children who are extroverted and may affect the development of their expressive skills [98]. Consequently, voice training should focus on children’s psychological and cognitive regulation to improve their incorrect vocal behaviors. For more details on the study of the effects of personality and children’s behavioral characteristics on children with voice disorders, see Lee et al [21].
> Surgery
The surgical treatment of vocal cord nodules or polyps in children is still controversial regarding indications and timing of surgery. Martins and colleagues [99] suggested that the age of surgery should be prolonged as much as possible because vocal fold nodules are likely to gradually disappear with age and that, with immature vocal fold development in children, The scars that may result from surgery can interfere with the normal development of the vocal cords even causing irreversible hoarseness [100].
In contrast, some researchers suggest that children with vocal fold nodules may be considered for surgical treatment by experienced laryngologists after 6 months when regular voice training has been found to be ineffective [101, 102], while Landa et al [103] recommended surgery for resection of vocal cord nodules in children older than 9 years of age.
Compared with vocal cord nodules, there is greater support for surgical intervention in children with vocal cord polyps. However, a standard protocol for timing of surgery is lacking, and some authors suggest that endolaryngeal microsurgery be performed if the child’s vocal cord polyp is not relieved after 3 months of conservative treatment.
Others have suggested that surgical intervention is advisable when frequent dysphonia and difficulty speaking severely affect children’s lives and communication [104].
In summary, voice training is the first choice for behavioral voice disorders in children. Although the short-term results of surgical treatment are beneficial, the long-term effects are unclear, and whether children will relapse after Surgery depends on a variety of factors. Therefore, further research on the indications for surgery, surgical approaches, and perioperative maintenance protocols for children with behavioral voice disorders is necessary for those whose voice training interventions are ineffective.
| Conclusion |
The immediate etiology of vocal disorders of voice behavior in children is well known, but the pathophysiological mechanisms are still poorly understood.
Current clinical recommendations use a stroboscopic laryngoscope to obtain clear vocal fold movements and for children who cannot cooperate, laryngeal ultrasound can also be used. In addition to the pVHI and PVRQOL scales, new subjective scales have been developed in recent years to assess the severity of speech disorders and their impact on children’s quality of life from different perspectives. However, treatment options for voice disorders in children with adverse vocal behavior remain controversial.
The preferred clinical treatment is voice training, but voice training patterns and procedures for children are still immature compared to those of adults, the effectiveness of treatment is uncertain, and the timing of surgical intervention for children who have not shown noticeable improvement after voice training is unclear; Therefore, there is a lack of comprehensive and standardized perioperative management for children who have failed conservative treatment, and the above issues will be the direction and challenges of future research.
| Comment |
Vocal disorders of voice behavior, with hoarseness being the most common symptom in children, are caused by several known causes. In this review, emphasis is placed on the adverse vocal habits of children, the family and personal situations that cause and perpetuate these disorders.
It is highlighted that conservative treatment with voice training is the first option, involving the family to participate and contain the child, favoring adherence to it.
. Although there is no consensus regarding optimal timing and long-term effectiveness, surgical treatment is considered as a second treatment option when voice training does not achieve the expected result.
