Pediatric voice disorders typically have been blamed on vocally "abusive" behaviors, and many practitioners have tended not to provide intervention because they believed that children would "grow out of it." However, changes in pitch, loudness, and overall vocal quality tend to interfere with communicative abilities. Recently, research has focused on pediatric voice disorders and the effects of a voice disorder on a child's life. It has been reported that children and adolescents felt that their voice disorders resulted in negative attention and limited their participation in activities (Connor, Cohen, Theis, Thibeault, Heatley, & Bless, 2008).
Incidence rates of pediatric voice disorders range from 6% to 23% (Maddern, Campbell, & Stool, 1991), with more than 1 million children in the United States affected by chronic dysphonia (Gumpert, Kalach, Dupont, & Contencin, 1998). Childhood dysphonia is a broad condition and can be difficult to quantify and study; however, several studies have shown that voice disruptions negatively affect how children are perceived both by adults and by their peers (Ruscello, Lass, & Podbesek, 1988; Lass, Ruscello, Stout, & Hoffmann, 1991; Lass, Ruscello, Bradshaw, & Blankenship, 1991). Although voice disorders are common in the pediatric population and have recently been gaining more attention, there is still a lack of information available to clinicians regarding evaluation and treatment of pediatric voice disorders.
SLP Shannon Theis performs a flexible fiberoptic endoscopy on a young patient.
The developing larynx and vocal tract change significantly from infancy to adulthood. Although the pediatric larynx differs from the adult larynx, clinicians often consider it as a miniature version of an adult's larynx when treating pediatric dysphonia. When an infant is born, the larynx is positioned very high in the neck, a location that facilitates the coordination of respiration and swallowing while feeding (Gray, Smith, & Schneider, 1996).
As the child grows, the larynx descends; the movement does not necessarily affect phonation, but it does affect the resonance of the vocal tract. As the infant's vocal tract continues to grow, the frequency of the vocal tract formants decreases, as does the fundamental frequency (Gray, Smith, & Schneider, 1996). Therefore, one of the most important features in the developing pediatric voice is the change in pitch as children get older. The laryngeal structure also changes. It has been shown that laryngeal growth is related to overall body growth. This growth accelerates from birth to age 3, then decelerates, then enters a rapid growth phase during adolescence and puberty, particularly in boys (Gray, Smith, & Schneider, 1996). Until puberty, the larynx is similar in size for boys and girls, and voices do not differ greatly (Maddern, Campbell, & Stool, 1991).
Causes of Disorders
Changes in the structure or function of the pediatric larynx can lead to dysphonia, and a child can present with a voice problem for a number of different reasons. A thorough review of pediatric voice disorders is beyond the scope of this article; in general, however, childhood dysphonia can be broadly classified into several categories: infectious, anatomic, congenital, inflammatory, neoplastic, neurologic, and iatrogenic (McMurray, 2003).
Vocal fold nodules are one of the most common forms of pediatric dysphonia (Maddern, Campbell, & Stool, 1991) and are considered inflammatory. Studies have estimated that the incidence of vocal fold nodules as the cause of pediatric dysphonia ranges from 38% to 78% (Gray, Smith, & Schneider, 1996). Vocal fold nodules are defined as swelling (usually bilaterally) in the mid-membranous portions of the true vocal fold that interferes with glottic closure and vocal fold vibration (Heman-Ackah, Kelleher, & Sataloff, 2002). Vocal nodules impede the normal vibratory pattern of the vocal folds and present what we hear acoustically as hoarseness. Vocal nodules are the most common—but not the only—cause of pediatric dysphonia; therefore, a thorough assessment and diagnosis are essential in the evaluation and treatment of pediatric voice disorders.
It is important to note that stridor (noisy inhalation or any other type of airway distress) is an important symptom to differentiate in pediatric voice disorders. Any type of voice change that is associated with airway symptoms or swallowing difficulties should be evaluated and treated immediately because it may be indicative of a potentially life-threatening condition (McMurray, 2003).
Evaluation of pediatric dysphonia requires a multidisciplinary approach to assess vocal function completely. A combined effort between a pediatric otolaryngologist and voice-trained speech-language pathologist is required as the first part of a child's care, with referrals to other medical specialties as needed. A complete pediatric voice evaluation involves many different components including a thorough medical history, acoustic and aerodynamic measures, perceptual judgments of voice quality during spontaneous speech, laryngeal visualization, and medical examination by a physician (McMurray, 2000).
It is imperative to obtain a thorough medical history as the first step in the voice evaluation to understand the onset, course of the problem, surgical history, and associated problems with breathing or swallowing. The specific issues of the dysphonia can aid in differential diagnosis. For example, intermittent dysphonia that is worse in the morning than at night may suggest gastroesophageal reflux. Persistent dysphonia with airway distress may suggest respiratory papillomatosis. Using child-friendly language to obtain the older child's perspective of symptoms is an important step, as parents are often unaware of—and sometimes surprised by—their child's response. For example, asking about "sour burps" or "mini throw-ups" when assessing reflux-related symptoms are terms that pediatric patients can understand and can lead to valuable information regarding their symptoms.
Two formal perceptual assessments commonly used among clinicians to rate voice quality are the GRBAS scale (Grade, Roughness, Breathiness, Asthenicity, Strain) and the CAPE-V (Consensus of Auditory Perceptual Evaluation of Voice). Both scales describe the severity of the voice disorder and its attributes.
However, perceptual rating of voice quality has been shown to be inconsistent across listeners (Millet, 1998). Although the "ear" is an important instrument in analyzing voice quality and always should be incorporated into the voice evaluation, objective measures, such as acoustic and aerodynamic assessments, offer supplemental unbiased documentation of voice change over time (Bless, Hirano, & Feder, 1987).
Acoustic and Aerodynamic Assessment
Acoustic measures can include quantification of fundamental frequency, vocal intensity, frequency and amplitude perturbation (jitter and shimmer), and signal-to-noise ratio (Case, 1999). Aerodynamic measurements of airflow and laryngeal airway resistance also are often calculated (Stemple, Glaze, & Klaben, 2000), although obtaining these measurements can be challenging in the pediatric population.
Proper evaluation and treatment of children with voice disorders requires reliable, quantitative recording and voice analyses for thorough assessment as well for measuring treatment outcomes following behavioral and/or surgical management. Campisi et al. (2002) recently established a database of pediatric normative values for use with the Multidimensional Voice Program (MDVP) based on 94 control subjects ages 4 to 12 years; this database increases the accessibility of computerized voice analysis system in pediatric dysphonia.
Endoscopic examination for laryngeal observation is essential in diagnosing pediatric voice disorders; an accurate diagnosis is otherwise virtually impossible (Hirschberg et al., 1995). According to ASHA's position statement on the use of endoscopy by speech-language pathologists (2008), endoscopy is included within the scope of practice for SLPs. Young children often are not able to tolerate stroboscopy with a rigid endoscope; therefore, a flexible endoscope is used (Chait & Lotz, 1991). The endoscopic evaluation helps assess the upper airway, laryngeal function and structure, and velopharyngeal function.
Adequately preparing a child to be as compliant as possible during this invasive procedure requires a great deal of skill. Typically, both child and caregiver have a great deal of anxiety. Time should be allowed to prepare the child and the family for the procedure in order to obtain the best possible images and exam, which will facilitate appropriate surgical, medical, and behavioral management. It is not enough to get a quick glimpse of the larynx—the goal is to obtain the most comprehensive examination possible with the least amount of discomfort and anxiety. Also, it is likely that the child will need to repeat the endoscopy in the future, so the experience should be as positive as possible to aid in future compliance.
Depending on the diagnosis, a number of treatment options are available for pediatric dysphonia. Treatment for vocal fold cysts often entails surgical removal from the submucosal layer of the vocal folds with as little disruption as possible to the surrounding tissues and mucosae. In recurrent respiratory papillomatosis, the voice and airway are both affected; therefore, surgical intervention is used to maintain an adequate airway while preserving the structures necessary for phonation (McMurray, 2000). Behavioral voice treatment is generally the recommended treatment for pediatric vocal nodules.
Traditional voice treatment typically focuses on vocal hygiene, worksheets, and reducing "abusive" voice behaviors, such as yelling. These approaches, however, have limited effectiveness. The traditional approach to voice treatment presents several problems:
The negative connotations of terms such as "vocal abuse" may cause children to feel as if they have done something wrong, but they see their friends engaging in the same type of behaviors without consequences.
Children are not typically motivated to change behavior based on traditional behavioral approaches.
Many children have been dysphonic since they began speaking, and therefore have no baseline. Adults, conversely, generally have experienced a "normal" voice and are typically motivated to return to that voice, but children may not have that same motivation.
Vocal hygiene and hydration have a role in pediatric voice treatment, but they should not be the only goals. Treatment should focus on directly improving vocal quality and establishing intrinsic motivators for the child to comply with treatment activities.
A variety of behavioral voice treatment approaches that focus on improving vocal technique can be used successfully with children. Typically, techniques used with children are similar to those used with adults, with some modifications: using child-friendly language, incorporating the child's caregiver into the sessions to help facilitate home practice and carry-over, and scheduling additional sessions to achieve treatment goals.
Resonant voice treatment is a common approach to pediatric voice treatment, with the goal of
achieving easy phonation through a barely abducted/barely adducted glottal configuration to produce high amplitude of vibration with low-impact stress (Verdolini, 1998). Treatment focuses on achieving a continuum of oral sensations and easy phonation, beginning with basic speech productions through conversational speech.
Voice treatment with children also can target diaphragmatic breathing, lip trills, stretching, and neck and laryngeal massage. Vocal function exercises also can be utilized with the pediatric population (Stemple, Glaze, & Klaben, 2000). The goals of treatment are to improve breath support, decrease excess muscle tension, improve vocal fold closure, and improve forward focus resonance, all in an effort to improve voice quality and decrease vocal effort and fatigue.
Voice treatment often focuses on concepts that are abstract for both adults and children and require the ability to self-monitor during productions. Therefore, approaches must be modified to be successful with children. Vocal hygiene, which is typically addressed in the initial session, should be presented as education rather than admonishment, with a discussion of alternatives rather than "good" versus "bad" choices. Vocal hygiene should include hydration discussions, behavioral modifications for reflux, and overall good vocal health.
Diaphragmatic breathing, resonant voice therapy, and vocal function exercises can be implemented easily with children using simple modifications to encourage motivation and skill acquisition. Finally, compliance can be an issue with voice treatment programs, but physical outcomes—such as a decrease in vocal fatigue, less pain or effort with speaking, and increased communicative effectiveness with peers and teachers—can be highly motivating to children.