Evaluating the Feasibility of Acapella® Choice as a Dysphonia Treatment

This feasibility study is the natural extension of the researchers' recently completed study (R\&D 16/0242) which assessed how the use of an Acapella Choice (Smiths Medical) positive expiratory pressure (PEP) device as a semi-occluded vocal tract exercise (SOVTE) impacted acoustic, electroglottographic and aerodynamic measures of the voice in a group of normophonic volunteers. In that study, Acapella Choice was found to offer significantly greater oscillating intraoral pressures than techniques in current clinical practice and was found to have measurable benefits in terms of producing a louder and more economical voice. It offered the largest oscillating pressures, likened to a 'massage' of the vocal organs, giving it great therapeutic promise for patients with excess vocal tract tension.

This study seeks to evaluate the immediate effects of Acapella Choice as a voice exercise in patients with Muscle Tension Dysphonia, Presbylaryngis and Vocal Fold Palsy, and compare this to the widely-used voice rehabilitation technique of phonation into a tube held under water (henceforward referred to as "Tube"). Patients will be recruited from four weekly Voice Clinics held at the Royal National Throat Nose and Ear Hospital where their diagnosis will be confirmed. They will be invited to attend a single experimental session during which time they will exercise both with Acapella Choice and with Tube. Baseline and outcome voice measures will be taken and a short questionnaire will be completed, eliciting perceptions of the two exercises and any changes which were felt to have resulted from them.

The researchers' previous work suggests that Acapella Choice as a SOVTE may offer significant clinical benefits in terms of improved efficacy of therapy. It is suggested that it also offers patients a more convenient and user-friendly form of exercise which may well improve compliance and result in better outcomes.

• Acapella Choice (Device), also known as PEP, Semioccluded vocal tract exercise: 3 minutes of exercise consisting of blowing through the device (on setting '5') and phonating at the same time.
• Tube-in-water (Device), also known as Lax Vox, Resonance tube in water, Semi-occluded vocal tract exercise: 3 minutes of exercise consisting of blowing through a silicone tube (10mm internal diameter) submerged in 5 cm of water whilst phonating at the same time.

Primary outcomes

• Change in Baseline Cepstral/Spectral Index of Dysphonia (CSID) [Immediately after 3 minutes of exercise]: A quantitative, multivariate, dysphonia summary tool that incorporates spectral (low/high spectral ratio) and cepstral measures (cepstral peak prominence), and their standard deviations, extracted from a continuous speech or sustained vowel sample utilising the software Analysis of Dysphonia in Speech and Voice (Kay Pentax, Montvale, NJ). The software calculates CSID on the scale of 0-100, whereby 0 represents no evidence of hoarse voice, and 100 represents a maximum amount of hoarseness. See: Awan SN, Roy N, Dromey C. Estimating dysphonia severity in continuous speech: Application of a multi-parameter spectralcepstral model estimating dysphonia severity in continuous speech. Clinical Linguistics and Phonetics. 2009;23(11):825-841. doi:10.3109/02699200903242988.

Secondary outcomes

• Change in Baseline Sound Pressure Level (dB) [Immediately after 3 minutes of exercise]: Intensity of vocal signal
• Change in Baseline Mean Contact Quotient [During 3 minutes of exercise (continual) and immediately following exercise.]: A percentage which illustrates the duration of vocal fold contact during one vocal fold period as measured by electroglottogram (EGG).
• Change in Subglottic Pressure [During 3 minutes of exercise (continual)]: Measures of air pressure in the mouth.
• Transglottic Airflow [During 3 minutes of exercise (continual)]: Measures of flow of air through the vocal tract.
• Change in Baseline Laryngeal Resistance [Immediately after 3 minutes of exercise]: Derived from dividing mean intraoral pressure during /p/ by mean transglottic airflow during /a/ during a task which elicits repetition of 'pa-pa-pa-pa-pa'
• Change in Baseline Perceptual Voice Quality [Immediately after 3 minutes of exercise]: Expert ratings of overall voice quality using a simple ad-hoc 100mm visual analog scale (ranging from 0-100, reflecting a scale of normal voice quality to highly abnormal voice quality {higher numbers reflect more abnormality}).
• Change in Baseline Participant Self-ratings - Voice Quality [Immediately after 3 minutes of exercise]: Participant self-rating of voice quality (on a 100mm visual analog scale (0-100) where higher numbers reflect self-perception of better voice quality/ease of production)

Sex: All, ages: 18 Years to 90 Years

Inclusion Criteria:

* Able to understand written English without the need for an interpreter,
* No diagnosed communication impairment
* Endoscopically confirmed primary ENT diagnosis of either:

  1. muscle tension dysphonia (with no laryngeal abnormality),
  2. Vocal fold palsy
  3. Presbylaryngis.

Exclusion Criteria:

* Previous SLT input
* Any of the following possible contraindications for PEP therapy:

  * Inability to tolerate increased work of breathing,
  * ICP (intracranial pressure) > 20mm Hg,
  * Recent facial/oral/skull surgery or trauma,
  * Oesophageal surgery,
  * Untreated pneumothorax,
  * Known or suspected tympanic membrane rupture/other middle ear pathology,
  * Haemodynamic instability,
  * Acute sinusitis,
  * Epistaxis,
  * Active haemoptysis,
  * Nausea

Participant flow

Outcome results

• Change in Baseline Cepstral/Spectral Index of Dysphonia (CSID) (Primary), Mean, score on a scale: Low Laryngeal Resistance 1.22 +/- 7.72; High Laryngeal Resistance 4.45 +/- 12.2
• Change in Baseline Sound Pressure Level (dB) (Secondary), Mean, dB: Low Laryngeal Resistance 0.79 +/- 1.97; High Laryngeal Resistance 1.46 +/- 2.72
• Change in Baseline Mean Contact Quotient (Secondary), Mean, percentage of contact: Low Laryngeal Resistance 0.01 +/- 0.04; High Laryngeal Resistance -0.01 +/- 0.06
• Change in Subglottic Pressure (Secondary), Mean, cmH2O: Low Laryngeal Resistance 0.16 +/- 1.72; High Laryngeal Resistance 0.95 +/- 1.81
• Transglottic Airflow (Secondary), Mean, l/s: Low Laryngeal Resistance 0.017 +/- 0.163; High Laryngeal Resistance 0.023 +/- 0.075
• Change in Baseline Laryngeal Resistance (Secondary), Mean, cmH20/l/s: Low Laryngeal Resistance 1.40 +/- 23.9; High Laryngeal Resistance -6.01 +/- 58.7
• Change in Baseline Perceptual Voice Quality (Secondary), Mean, units on a scale: Low Laryngeal Resistance -1.82 +/- 6.03; High Laryngeal Resistance 0.175 +/- 4.73
• Change in Baseline Participant Self-ratings - Voice Quality (Secondary), Mean, units on a scale: Low Laryngeal Resistance 12.3 +/- 13.8; High Laryngeal Resistance 4.62 +/- 9.05

Adverse events

Time frame: 1 week

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• Study Protocol and Statistical Analysis Plan (PDF, 2020-09-15)

• Brian Saccente-Kennedy, MSc, Principal investigator, University College London Hospitals