Voice Disorders: Management by Speech Therapy of Dysphonias

Complex physiology of vocal production

Vocal production is an extraordinarily complex phenomenon that involves the perfect coordination of three distinct anatomical and physiological levels. This sophisticated mechanism allows for the creation of articulated sounds that form the basis of our oral communication. Understanding this physiology is essential for any speech therapist wishing to intervene effectively on vocal disorders.

The first level, called the blower, includes the entire respiratory system: the lungs, diaphragm, intercostal muscles, abdominal muscles, and accessory respiratory muscles. These structures provide the air pressure necessary for the vibration of the vocal cords. Effective breathing is the foundation of a quality voice, and many vocal disorders originate from poor breath management.

The second level constitutes the laryngeal vibrator, where the vocal cords are located. These musculo-membranous structures, stretched between the thyroid cartilage and the arytenoid cartilages, vibrate under the effect of expiratory air pressure. The frequency of this vibration determines the pitch of the sound produced, while the amplitude influences vocal intensity. The quality of contact between the vocal cords and their flexibility determine the vocal timbre.

The third level includes the resonators: pharynx, oral cavity, nasal cavities, and sinuses. These cavities amplify and color the fundamental sound produced at the laryngeal level, creating the characteristic vocal timbre of each individual. The modification of the shape and volume of these cavities allows for the production of the different phonemes of speech.

Detailed classification of dysphonias

Dysphonias are classified according to several criteria: their etiological origin, their degree of severity, their temporal evolution, and their functional impact. This classification oriented towards clinical practice allows the speech therapist to adapt their management according to the specific profile of each patient and the involved pathophysiological mechanisms.

Organic dysphonias result from a visible anatomical lesion of the vocal cords or their surrounding structures. These lesions can be benign (nodules, polyps, Reinke's edema, cysts) or malignant (carcinomas). They can also be of traumatic, inflammatory, or neurological origin (laryngeal paralysis). The prognosis and management differ significantly depending on the nature of the lesion.

Functional dysphonias, representing about 60% of cases, do not present an initially visible anatomical lesion. They result from improper vocal use, often related to inappropriate behavioral habits, chronic vocal strain, or psycho-emotional factors. These dysphonias can evolve into secondary organic lesions if not managed early.

Psychogenic dysphonias constitute a particular category where psychological mechanisms play a predominant role. They can manifest as complete aphonia (total loss of voice) or significant changes in vocal parameters without anatomical substrate. The emotional context and life events are determining factors in these cases.

Modern multidimensional vocal assessment

Speech therapy vocal assessment is a crucial step that determines therapeutic orientation. This multidimensional assessment combines perceptual, acoustic, aerodynamic, and functional approaches to obtain a comprehensive view of the vocal disorder. It relies on standardized tools and increasingly sophisticated technologies.

The detailed anamnesis explores the history of the vocal disorder, the circumstances of onset, the temporal evolution, professional and personal vocal use, lifestyle habits, and medical and surgical history. This step allows for the identification of etiological factors and essential prognostic elements for therapeutic planning.

The perceptual assessment uses standardized scales such as the GRBAS scale (Grade, Roughness, Breathiness, Asthenia, Strain) or the CAPE-V protocol (Consensus Auditory-Perceptual Evaluation of Voice). These tools allow for a systematic and reproducible analysis of the perceptual characteristics of the pathological voice, facilitating the monitoring of evolution under treatment.

Aerodynamic evaluation includes measuring the maximum phonation time on different vowels, calculating the s/z ratio (reflecting glottic efficiency), measuring subglottic pressures, and phonatory airflow. These parameters provide information about the efficiency of the respiratory-phonatory coordination and glottic closure.

The patient's self-assessment, particularly through the Voice Handicap Index (VHI), evaluates the impact of dysphonia on quality of life across three dimensions: functional (limitations in daily activities), physical (vocal sensations and efforts), and emotional (psychological impact). This tool allows for measuring the effectiveness of care from the patient's perspective.

Principles and Objectives of Vocal Rehabilitation

Vocal rehabilitation aims to restore optimal laryngeal function by modifying vocal forcing behaviors and developing an effective, economical, and comfortable vocal gesture. This holistic approach integrates the respiratory, postural, technical, and psycho-emotional dimensions of vocal disorders.

The main objective is to enable the patient to regain a functional voice that meets their personal and professional needs. This involves correcting pathological mechanisms, learning new vocal strategies, and integrating these new behaviors into daily life. Rehabilitation must be tailored to the specificities of each patient.

Awareness is the first fundamental step. The patient must understand the mechanisms behind their vocal disorder and identify forcing situations. This educational phase relies on simple anatomical explanations, visual aids, and vocal proprioception exercises that allow the patient to develop their self-assessment abilities.

The basic work focuses on optimizing breathing, improving posture, and reducing unnecessary muscle tension. Effective costal-abdominal breathing forms the foundation of any quality voice. Progressive exercises help develop respiratory control and the essential pneumo-phonic coordination for easy phonation.

Specialized re-educational techniques and methods

The speech therapist has a wide range of re-educational techniques that they adapt according to the patient's profile, the nature of the vocal disorder, and the therapeutic objectives. These approaches, derived from different methodological currents, can be combined synergistically to optimize therapeutic outcomes.

The manual method, developed by François Le Huche, offers a holistic approach to body-breath-voice. It emphasizes the use of breath exercises, progressive vocalizations, and manual techniques to promote laryngeal and peri-laryngeal relaxation. This method particularly stresses the coordination between the different levels of phonation.

The LSVT (Lee Silverman Voice Treatment) is an intensive approach specifically developed for patients with Parkinson's disease. This standardized protocol, based on increasing vocal intensity and improving movement amplitude, has demonstrated its effectiveness in the rehabilitation of vocal hypokinesia of neurological origin.

Vocal function exercises, developed by Stemple, consist of specific vocalizations aimed at "muscling" and relaxing the phonatory system. These exercises, performed systematically and progressively, improve the strength, endurance, and flexibility of the laryngeal muscles involved in phonation.

The postural approach integrates work on body alignment, reduction of cervical-facial tensions, and optimization of overall statics. Posture directly influences respiratory and vocal quality. Techniques from various disciplines (Feldenkrais, Alexander, yoga) enrich the therapeutic arsenal of the speech therapist.

Particularities of the Voice of Professionals

Voice professionals (teachers, salespeople, artists, speakers, lawyers) constitute a population particularly exposed to vocal disorders. Their management requires a specific approach that takes into account the constraints and demands of their professional activity. The goal is to reconcile vocal performance and preservation of the vocal instrument.

Teaching represents the profession most affected by vocal disorders, with a prevalence that can reach 50% according to studies. The risk factors are numerous: intensive vocal use, noisy environments, stress, chalk dust, inadequate air conditioning. Prevention and training in vocal use are essential in this profession.

Lyric artists and singers have specific needs related to the technical demands of their art. Rehabilitation must preserve artistic capabilities while correcting dysfunctions. Close collaboration with singing teachers and vocal coaches is often necessary to optimize management.

The medico-legal dimension of professional vocal disorders requires precise documentation of assessment and therapeutic follow-up. The speech therapist must establish clear links between professional vocal use and the observed disorder, relying on validated assessment tools and an ergonomic analysis of vocal activity.

Dysphonia in children: developmental specificities

Childhood dysphonia presents particularities related to the anatomical and functional development of the larynx, behavioral habits, and the family and school context. Assessment and management must be adapted to the child's age and actively involve those around them in the therapeutic process.

Vocal nodules are the most common pathology in children, particularly in boys aged 5 to 10 years. They often result from chronic vocal strain behavior (screaming, sound imitations, inappropriate singing) favored by an extroverted temperament and a noisy environment. The prognosis is generally favorable with early management.

Assessment in children prioritizes behavioral observation, listening in natural situations, and the use of playful tools appropriate for their age. Acoustic analysis can be difficult to perform in young children due to behavioral variability and the difficulty of maintaining stable phonation. Perceptual assessment therefore remains predominant.

Pediatric vocal rehabilitation prioritizes playful and creative approaches. Voice games, sound stories, animal imitations, and songs provide motivating supports for the child. The goal is to develop body and vocal awareness while gradually correcting inappropriate behaviors.

The involvement of the family and school environment is crucial for therapeutic success. Parents and teachers must be made aware of good vocal hygiene practices and learn to identify situations of vocal strain. Environmental adjustments (noise reduction, vocal breaks) may be necessary.

Vocal hygiene and prevention: essential foundations

The prevention of vocal disorders relies on education about vocal hygiene and the modification of behavioral and environmental risk factors. This preventive approach is particularly important for voice professionals and should be integrated from the initial vocal training.

Hydration is a fundamental element of vocal hygiene. The vocal cords need optimal hydration to vibrate correctly. Sufficient water intake (1.5 to 2 liters per day), limiting dehydrating substances (alcohol, caffeine), and humidifying the ambient air contribute to maintaining the hydration of the vocal mucosa.

Avoiding tobacco is an absolute priority in vocal hygiene. Smoking causes chronic inflammation of the respiratory tract, dehydration of the mucosa, and significantly increases the risk of benign and malignant lesions of the vocal cords. Quitting smoking is accompanied by a rapid improvement in vocal quality.

Managing gastroesophageal reflux (GERD) is essential as gastric acidity can rise to the larynx and cause inflammation of the vocal cords. Dietary measures (avoiding late meals, acidic and spicy foods) and postural measures (raising the head of the bed) can significantly improve vocal symptoms related to GERD.

The work environment must be optimized: reducing background noise, improving room acoustics, using amplification systems if necessary. Regular vocal breaks help prevent fatigue and inflammation of the vocal cords during intensive vocal use.

Modern Technologies and Therapeutic Innovations

Technological evolution is gradually revolutionizing the practice of vocal rehabilitation. New assessment and rehabilitation tools are emerging, offering unprecedented possibilities for vocal analysis and therapeutic management. These innovations complement the traditional arsenal of the speech therapist without replacing it.

Real-time acoustic analysis allows the patient to instantly visualize the parameters of their vocal production (frequency, intensity, spectral quality). These biofeedback systems facilitate awareness and learning of new vocal behaviors. Mobile applications now offer vocal analysis tools accessible to the general public.

Virtual reality is beginning to be explored for vocal rehabilitation, particularly to reproduce stressful communication situations or complex acoustic environments. This technology allows for gradual training in controlled conditions before transferring to real life.

Surface electromyography allows for the recording of the activity of the laryngeal and peri-laryngeal muscles, providing an objective approach to assessing muscle tension. This technique can guide rehabilitation by precisely identifying dysfunctional muscle groups and objectifying the effectiveness of relaxation techniques.

Tele-therapy is rapidly developing, particularly since the COVID-19 pandemic. Although the initial assessment generally requires an in-person consultation, therapeutic follow-up can benefit from these new modalities, allowing for continuity of care and easier access for geographically isolated patients.

Psycho-emotional approach to vocal disorders

The psycho-emotional dimension of vocal disorders is often underestimated, yet it plays a determining role in the onset, maintenance, and recovery of dysphonias. The speech therapist must integrate this dimension into their assessment and management, in collaboration with other professionals if necessary.

Chronic stress causes muscle tension that directly affects vocal quality. The laryngeal and peri-laryngeal muscles contract, altering laryngeal position and respiratory-phonatory coordination. Stress management is therefore an integral part of vocal rehabilitation and may require the learning of specific relaxation techniques.

Psychic trauma can manifest as vocal disorders, ranging from simple changes in timbre to complete aphonia. These psychogenic dysphonias require a delicate approach, combining vocal techniques and psychological support. Collaboration with a psychologist or psychiatrist may be necessary.

Self-esteem and confidence in one's voice are closely linked to vocal quality. Dysphonic patients often develop an apprehension of oral communication that maintains and worsens the disorder. Rebuilding vocal confidence is a major therapeutic goal, requiring patience and encouragement.

Professional and relational factors significantly influence the voice. Conflicts at work, relational difficulties, and professional overloads can manifest as vocal disorders. The medical history must explore these dimensions, and management may require environmental adjustments.

Long-term follow-up and prevention of recurrences

Long-term follow-up is a crucial element in the management of vocal disorders. Recurrences are common, particularly among voice professionals, and require ongoing vigilance as well as personalized support to maintain therapeutic gains over time.

Educating the patient on self-assessment of their voice allows for early detection of signs of recurrence. Simple tools like a vocal journal, daily self-assessment scales, or mobile voice analysis applications can help the patient maintain active monitoring of their voice and adjust their behaviors accordingly.

Scheduled follow-up consultations allow for regular monitoring of vocal evolution and readjustment of management if necessary. These consultations can be spaced progressively (3 months, 6 months, then annually) depending on the patient's progress and persistent risk factors.

Continuous adaptation to professional and personal changes is essential. Changes in professional activity, hormonal modifications (menopause, pregnancy), aging, or the emergence of new pathologies may require readjustment of vocal management. A flexible and personalized approach is indispensable.

Continuous training of the professional environment (colleagues, hierarchy) in recognizing signs of vocal fatigue and preventive measures contributes to creating a favorable environment for maintaining good vocal hygiene. This collective awareness can effectively prevent recurrences related to environmental factors.