Understanding Resonant Voice Therapy

In the realm of vocal health and speech pathology, the term "resonant voice" refers to a specific quality of sound production that is both powerful and produced with minimal effort. This is not merely about speaking loudly, but about engaging the vocal tract in a way that amplifies the sound efficiently and comfortably. Understanding what constitutes a resonant voice is crucial for individuals experiencing voice difficulties, such as hoarseness, vocal fatigue, or strain. One of the most recognized and effective therapeutic approaches for achieving this is the Lessac-Madsen Resonant Voice Therapy (LMRVT).

What is Resonant Voice?

At its core, resonant voice is a vocal technique that focuses on maximizing vocal efficiency and minimizing vocal fold strain. It is characterised by a forward placement of the vocal sensations, often felt as vibrations along the anterior alveolar ridge (the ridge behind your upper front teeth). When producing a resonant voice, the sound is perceived as clear, strong, and forward, without the feeling of pushing or straining the throat. This is achieved by optimising the way the vocal folds vibrate and how the sound resonates within the vocal tract, particularly the epilarynx tube, a part of the upper airway that plays a significant role in vocal resonance.

The Science Behind Resonant Voice

Research, notably by Dr. Katherine Verdolini and her colleagues, has indicated that a specific vocal fold posturing, described as "barely abducted" or "barely adducted," is key to producing a resonant voice. This optimal glottal width, estimated to be around 0.6 mm, allows for maximum intraglottal pressure, contributing to vocal strength, while simultaneously minimising the impact stress on the vocal folds. This is vital for preventing vocal injury and promoting healing. Unlike complete vocal rest, which can sometimes be less effective in promoting healing of phonotraumatic lesions, LMRVT actively encourages a healthy vibratory pattern that aids recovery and improves vocal function.

Lessac-Madsen Resonant Voice Therapy (LMRVT)

Developed by Dr. Katherine Verdolini, LMRVT is a comprehensive voice therapy program that draws upon the foundational work of Dr. Arthur Lessac and Dr. Mark Madsen. Lessac's expertise in resonant voice production and Madsen's contributions to motor learning form the bedrock of this therapy. LMRVT is designed to address a wide range of voice disorders, irrespective of their specific diagnosis, by guiding patients towards this efficient vocal behaviour.

Origins and Philosophy

LMRVT was conceptualised in the early 2000s, with Verdolini naming the therapy in honour of her mentors. The therapy's unique approach lies in its ability to correct both hypo- (under-adducted) and hyper- (over-adducted) vocal fold posturing. The primary goals for most patients with voice disorders are a strong, clear voice and the prevention of further vocal injury. LMRVT directly targets these goals by promoting the barely ab/adducted laryngeal posture, which scientific evidence suggests is ideal for achieving vocal strength with minimal impact stress.

Key Components of LMRVT

LMRVT is built upon three fundamental pillars, which Verdolini refers to as "the what," "the how," and "the if":

The "What": Biomechanics and Vocal Hygiene

This component focuses on the physiological aspects of voice production. It involves teaching the patient how to achieve the optimal vocal fold posturing for resonant voice. This includes vocal hygiene practices, such as adequate hydration, which can reduce the lung pressure needed for vocal fold vibration, leading to a sensation of decreased effort. Patients are also educated on behaviours to avoid, like screaming, which can cause significant vocal injury due to hyperadduction and high amplitude vibrations. The therapy also addresses other contributing factors, such as reflux, which can exacerbate vocal issues.

The "How": Motor Learning Principles

A distinctive feature of LMRVT is its reliance on motor learning principles. Research indicates that focusing too intensely on the mechanics of a motor skill can hinder immediate performance and long-term retention. Therefore, LMRVT prioritises the patient's sensory awareness. Clinicians guide patients to identify the feeling of resonant voice rather than focusing on specific physical actions. This sensory-based approach, coupled with limited feedback and elements of random and variable practice, aims to maximise the patient's ability to learn, retain, and apply the new vocal behaviours effectively outside the therapy setting.

The "If": Patient Compliance and Integration

The success of any therapy hinges on patient compliance – the willingness and ability to implement learned skills in daily life. LMRVT places a strong emphasis on this by tailoring the therapy to the individual's lifestyle. Voice hygiene programs are personalised, and practice is integrated into daily routines. Patients are actively involved in developing their post-therapy self-care plans, ensuring relevance and adherence. A key advantage is that resonant voice readily transfers to louder speech, allowing patients to maintain their improved vocal quality in various speaking situations without compromising performance.

Therapeutic Methods and Progression

The foundational gesture of LMRVT is the "basic training gesture" (BTG), which aims to elicit the patient's best representation of resonant voice. Following a series of body stretches to promote overall relaxation and body awareness, the clinician guides the patient through a process of self-observation and physical exploration. This guidance often follows the "scan-gel-show-tell" principle, beginning with self-awareness and physical manipulation, then demonstration, and finally, verbal instruction as a last resort.

Once a patient can identify the sensations associated with resonant voice, the therapy progresses to simple phonemes. Specially designed "bridging exercises" gradually introduce more complex voicing patterns, building upon the BTG. The ultimate goal is for the patient to produce normal, conversational speech using the resonant voice quality. Throughout this process, clinicians also focus on the patient's use of inflection to ensure that the resonant voice behaviour becomes a natural and accessible part of their communication.

Crucially, patients are expected to exhibit evidence of improved voice quality and reduced phonatory effort within the first session. This immediate positive feedback is essential for reinforcing the efficacy of the method and motivating the patient to continue.

Efficacy and Evidence

While LMRVT is widely regarded as effective, the body of statistically validated research is still growing. However, preliminary studies have shown promising results. One unpublished study indicated that sensory learning and variable practice – core components of LMRVT – yielded better long-term results than metaphoric learning and non-variable practice, respectively. This supports the therapy's emphasis on self-awareness and varied practice for optimal learning.

Another unpublished study focused on the effects of LMRVT on vocal fold healing. The findings suggested that LMRVT led to more complete vocal fold healing in a shorter period compared to complete voice rest or spontaneous speech. This provides strong evidence for using LMRVT to heal phonotraumatic lesions, potentially offering a more active and efficient alternative to traditional voice rest.

Areas for Further Research

Despite the positive indications, there is a need for more statistically significant studies that directly compare LMRVT with other popular voice therapy methods. Such research would help to definitively establish LMRVT's comparative effectiveness in terms of learning, compliance, and the achievement of biomechanical, medical, and functional goals.

Summary of LMRVT's Strengths

LMRVT distinguishes itself through its comprehensive approach, addressing the needs of a diverse patient population. Its strong foundation in biomechanics, cognitive learning science, and compliance research makes it a robust therapeutic model. The therapy's ability to correct both hypo- and hyperadducted vocal fold configurations, promote efficient voice production, and enhance vocal healing is well-supported. While ongoing research will further refine our understanding of its comparative advantages, LMRVT stands out as a highly effective and evidence-informed method for improving vocal health and function.

Frequently Asked Questions

What does "resonant voice" feel like?

Resonant voice typically feels like a "buzzing" or "vibratory" sensation in the front of your face, particularly around the nose and the alveolar ridge (the ridge behind your upper teeth). It should feel effortless and easy to produce.

Can LMRVT help with vocal nodules?

Yes, studies suggest that LMRVT can be effective in promoting the healing of vocal fold lesions, such as nodules, often more effectively and in a shorter timeframe than complete voice rest.

How long does LMRVT typically take?

Verdolini recommends delivering LMRVT in 45-minute weekly sessions for approximately 8 weeks, though the duration can be adjusted based on individual patient needs and schedules.

Is LMRVT suitable for singers?

Absolutely. LMRVT is beneficial for singers as it teaches efficient vocal production, which can improve vocal power, stamina, and reduce the risk of injury, all crucial for vocal performance.

What is the difference between resonant voice and belting?

Resonant voice focuses on efficient amplification through resonance with minimal strain, feeling forward and easy. Belting, while it can be powerful, often involves a different vocal mechanism that can be more strenuous if not executed correctly, and may not always prioritize the same level of vocal efficiency or comfort.

Can I practice resonant voice on my own?

While LMRVT is best guided by a qualified speech-language pathologist, understanding the principles of resonant voice can help you become more aware of your vocal production. However, it's recommended to seek professional guidance to ensure you are using the technique correctly and safely.