A Proof-of-concept Study of the Complete Vocal Technique (CVT), a Pedagogic Technique Used for Performers, in Improving the Voice and Vocal Function in Patients With Muscle Tension Dysphonia Using Telehealth

Voice problems (dysphonia) affect one in 13 adults annually, causes a major impact on quality of life and livelihood and is a substantial healthcare burden. It is more common in women and in those with vocally demanding professions and the elderly. Forty percent of patients referred for assessment of a voice problem have Muscle Tension Dysphonia (MTD) as a cause brought on by an imbalance of breathing mechanism and/or uncontrolled tightness of the muscles of the voice box or throat. The main symptoms are hoarseness, abnormal pitch or loudness, variability in quality or control of the voice, throat discomfort or difficulty in using the voice such as being able to use a louder voice when needed, or a voice that fatigues with use with a consequent impact on quality of life. Traditionally there are six described recognisable patterns of MTD based on the presenting symptoms, voice quality and on appearance of the larynx (voice box) on examination with a video camera. Three types (MTD patterns I-III) are more related to ineffective voice use, also known as 'voice abuse' or 'voice misuse', while the other three types (MTD patterns IV-VI) have a predominantly psychological basis.

In the United Kingdom (UK), patients with persistent or unexplained hoarseness who are over the age of 45 are referred under the two-week wait (2WW) cancer referral process. In other cases, referral to an Ear, Nose and Throat (ENT) benign voice service is usually considered if the dysphonia persists for more than six weeks, if it has not improved with simple measures such as voice rest, reducing irritation to the vocal cords and drinking plenty of fluids (known as vocal hygiene advice) or it is impacting significantly on the patient's work or social life. In practice patients with MTD may come through both the 2WW and benign voice pathways.

A diagnosis of MTD is made by an ENT surgeon and/or Speech & Language Therapist who has specialised in voice disorders (SLT-V) based on the history of the vocal complaint and by excluding an organic cause by examination of the patient's voice box (larynx) with a small flexible video camera passed through the nose. Treatment is with voice therapy given by a SLT-V. Voice therapy consists of two main types: Indirect Voice Therapy and Direct Voice Therapy and is guided by advice from professional organisations such as Royal College of Speech and Language Therapists Clinical Guidelines and the American Speech-Language-Hearing Association (ASHA) Clinical Practice Guideline: hoarseness (dysphonia). Indirect therapy consists of education, information, vocal hygiene, and stress management to encourage behavioural change. Direct therapy consists of establishing healthy voice production by rebalancing the three subsystems of voice production namely breathing (respiration), voice production (phonation) and more efficient use of resonance.

The aim of voice therapy is generally to (a) return the patient's voice to normal or as best as possible within the patient's anatomic and physiologic capabilities and (b) to satisfy the patient's occupational, social and emotional vocal needs and (c) promote habit changes that will ensure voice improvement will be maintained. Therapeutic goals should be specific and determined by the patient prior to therapy to empower the patient in shared decision making with the aim of improving motivation and compliance. In addition, the aim should be maximum improvement in the minimum time.

MTD is a mixed group of conditions with different patterns of presentation and numerous patient specific factors. In addition, Direct Voice Therapy is not just one treatment method and many SLT-Vs use a hierarchical approach, which focuses in the early stages on postural and relaxation techniques, followed by breathing exercises, voicing and resonance work with final consolidation and review. The techniques applied by a SLT-V are also dependent on abnormal findings on clinical examination the training and experience of the therapist and the response and engagement of the patient. Although having a large variety of techniques that can be used which can be tailored to the individual, Voice therapy has been portrayed as a "black box" and many recognised treatment regimens overlap in the treatment aims and therapeutic goals. This makes it difficult to determine why patients improve, which therapy tasks are most beneficial and for how long the tasks should be continued.