Evaluating a Vibratory Positive Expiratory Pressure (PEP) Device as a Dysphonia Treatment

  • Author Footnotes
    2 First author.
    Brian Saccente-Kennedy
    Address correspondence and reprint requests to Brian Saccente-Kennedy, Department of Speech and Language Therapy (ENT), Royal National Ear, Nose and Throat and Eastman Dental Hospitals, University College London Hospitals NHS Foundation Trust, 47-49 Huntley Street, London, WC1E 6DG, United Kingdom.
    2 First author.
    Department of Speech and Language Therapy (ENT), Royal National Ear, Nose and Throat and Eastman Dental Hospitals, University College London Hospitals NHS Foundation Trust, London, United Kingdom
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  • Pedro Amarante Andrade
    Academy of Performing Arts in Prague, Research Center of Music Acoustics, Prague 1, Czech Republic
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  • Ruth Epstein
    Department of Speech and Language Therapy (ENT), Royal National Ear, Nose and Throat and Eastman Dental Hospitals, University College London Hospitals NHS Foundation Trust, London, United Kingdom
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  • Author Footnotes
    2 First author.
Published:October 28, 2022DOI:



      Previous work investigating Acapella Choice, a vibratory positive expiratory pressure device, as a form of semi-occluded vocal tract exercise (SOVTE) identified that it promoted large oscillatory pressures and promoted improved vocal economy for normophonic volunteers. Its use in a pathological population has not yet been investigated.


      To assess the impact of Acapella Choice as an SOVTE in a group of dysphonic patients and compare outcomes to tube-in-water resistance therapy.


      Thirty participants underwent acoustic, electroglottography (EGG) and aerodynamic assessment before and after 3 minutes of phonation with Acapella Choice and with a 9 mm diameter tube in 5 cm of water (WRT). During exercise, aerodynamic and EGG signals were captured simultaneously. Descriptive statistics and tests of significant differences between groups and exercises were carried out. Outcome variables included expert-rated voice quality, sound pressure level, difference in first and second harmonics (H1-H2), cepstral peak prominence, mean contact quotient (CQ), mean peak pressure, mean flow during voicing, laryngeal resistance and aerodynamic power. Participants rated their perceived vocal clarity, strength, and effortlessness as well as vocal tract discomfort utilizing the Vocal Tract Discomfort Scale.

      Results and Conclusions

      Participants were clustered based on baseline laryngeal resistance, resulting in a high resistance (HR, n = 14) and low resistance (LR, n = 16) groups. Acapella produced twice the static intraoral pressure and oscillatory (root mean square) pressure and flow compared to WRT. Both exercises produced similar static flows. Acapella oscillation frequency was higher than WRT bubbling, but not meaningfully. Flow increased significantly from pre-intervention levels to perform both exercises, and further increased during the task. The glottal response of the groups was categorically different; the HR group had an immediate drop in CQ commencing both tasks, while the LR group demonstrated a steady decline in CQ in Acapella only. Following Acapella, CQ and H1-H2 trended towards normalization. Acapella also produced larger aerodynamic changes. Measures of voice quality deteriorated modestly following both exercises. By contrast, participant ratings of voice production were significantly improved after both tasks, more so with Acapella. The HR group reported significant reductions in tightness and aching following Acapella. Participants favored Acapella, finding it more practical and more likely to be used for daily practice.

      Key Words

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        • Titze IR.
        Voice training and therapy with a semi-occluded vocal tract: rationale and scientific underpinnings.
        Hear Res. 2006; 49: 448-460
        • Menezes MHM
        • Ubrig-Zancanella MT
        • Cunha MGB
        • et al.
        The relationship between tongue trill performance duration and vocal changes in dysphonic women.
        J Voice. 2011; (Published online)
        • Guzman M
        • Acuña G
        • Pacheco F
        • et al.
        The impact of double source of vibration semioccluded voice exercises on objective and subjective outcomes in subjects with voice complaints.
        J Voice. 2018; 32: 770.e1-770.e9
        • Guzman M
        • Calvache C
        • Romero L
        • et al.
        Do different semi-occluded voice exercises affect vocal fold adduction differently in subjects diagnosed with hyperfunctional dysphonia?.
        Folia Phoniatr Logop. 2015; (Published online)
        • Guzman M
        • Castro C
        • Testart A
        • et al.
        Laryngeal and pharyngeal activity during semioccluded vocal tract postures in subjects diagnosed with hyperfunctional dysphonia.
        J Voice. 2013; (Published online)
        • Andrade PA
        • Wood G
        • Ratcliffe P
        • et al.
        Electroglottographic study of seven semi-occluded exercises: LaxVox, straw, lip-trill, tongue-trill, humming, hand-over-mouth, and tongue-trill combined with hand-over-mouth.
        J Voice. 2014; 28: 589-595
        • Calvache C
        • Guzman M
        • Bobadilla M
        • et al.
        Variation on vocal economy after different semioccluded vocal tract exercises in subjects with normal voice and dysphonia.
        J Voice. 2019; (Published online)
        • Frisancho K
        • Salfate L
        • Lizana K
        • et al.
        Immediate effects of the semi-occluded ventilation mask on subjects diagnosed with functional dysphonia and subjects with normal voices.
        J Voice. 2018; (Published online): 1-12
        • Laukkanen AM
        • Horáček J
        • Krupa P
        • et al.
        The effect of phonation into a straw on the vocal tract adjustments and formant frequencies. A preliminary MRI study on a single subject completed with acoustic results.
        Biomed Signal Process Control. 2012; 7: 50-57
        • Laukkanen AM.
        About the so called “resonance tubes” used in Finnish voice training practice: an electroglottographic and acoustic investigation on the effects of this method on the voice quality of subjects with normal voice.
        Scandinavian J Logoped Phoniatr. 1992; 17: 151-161
        • Simberg S
        • Laine A.
        The resonance tube method in voice therapy: description and practical implementations.
        Logoped Phoniatr Vocolog. 2007; (Published online)
        • Saters TL
        • Ribeiro VV
        • Siqueira LTD
        • et al.
        The voiced oral high-frequency oscillation technique's immediate effect on individuals with dysphonic and normal voices.
        J Voice. 2018; (Published online)
        • Hencke D
        • Oliveira Rosa C
        • Emygdio da Silva Antonetti A
        • Alves A. Silverio K C
        • Siqueira L
        Immediate effects of performance time of the voiced high-frequency oscillation with two types of breathing devices in vocally healthy individuals.
        J Voice. 2021;
        • da Silva Antonetti AE
        • Ribeiro VV
        • Moreira PAM
        • et al.
        Voiced high-frequency oscillation and LaxVox: analysis of their immediate effects in subjects with healthy voice.
        J Voice. 2018; (Published online)
        • Antonetti AE da S
        • Ribeiro VV
        • Brasolotto AG
        • et al.
        Effects of performance time of the voiced high-frequency oscillation and Lax Vox technique in vocally healthy subjects.
        J Voice. 2022; 36: 140.e29-140.e37
        • Saccente-Kennedy B
        • Amarante Andrade P
        • Epstein R
        A pilot study assessing the therapeutic potential of a vibratory positive expiratory pressure device (Acapella Choice) in the treatment of voice disorders.
        J Voice. 2020; 34: 487.e21-487.e30
        • Andrade PA
        • Frič M
        • Saccente-Kennedy B
        • et al.
        Pressure, flow, and glottal area waveform profile changes during phonation using the acapella choice device.
        J Voice. 2022; (Published online): 1-11
        • Laukkanen AM
        • Horáček J
        • Radolf V.
        Buzzer versus water resistance phonation used in voice therapy. Results obtained with physical modeling.
        Biomed Signal Process Control. 2021; 66102417
        • Guzman M
        • Laukkanen AM
        • Traser L
        • et al.
        The influence of water resistance therapy on vocal fold vibration: a high-speed digital imaging study.
        Logoped Phoniatr Vocol. 2017; (Published online)
        • Guzmán M
        • Castro C
        • Madrid S
        • et al.
        Air pressure and contact quotient measures during different semioccluded postures in subjects with different voice conditions.
        J Voice. 2016; (Published online)
        • Guzman M
        • Castro C
        • Acevedo K
        • et al.
        How do tube diameter and vocal tract configuration affect oral pressure oscillation characteristics caused by bubbling during water resistance therapy?.
        J Voice. 2020; (Published online)
        • Cardinale M
        • Bosco C.
        The use of vibration as an exercise intervention.
        Exerc Sport Sci Rev. 2003; (Published online)
        • Echternach M
        • Köberlein M
        • Gellrich D
        • et al.
        Duration of biodynamic changes associated with water resistance therapy.
        Logoped Phoniatr Vocol. 2020; 0: 1-8
        • Švec JG
        • Granqvist S.
        Tutorial and guidelines on measurement of sound pressure level in voice and speech.
        J Speech Lang Hear Res. 2018; 61: 441-461
        • MATHIESON L
        Vocal tract discomfort in hyperfunctional dysphonia.
        J Voice. 1993; 2: 40-48
        • Awan SN
        • Roy N
        • Jetté ME
        • et al.
        Quantifying dysphonia severity using a spectral/cepstral-based acoustic index: comparisons with auditory-perceptual judgements from the CAPE-V.
        Clin Linguist Phonetics. 2010; 24: 742-758
        • Zraick RI
        • Smith-Olinde L
        • Shotts LL.
        Adult normative data for the KayPENTAX phonatory aerodynamic system model 6600.
        J Voice. 2012; 26: 164-176
        • Howard DM.
        Variation of electrolaryngographically derived closed quotient for trained and untrained adult female singers.
        J Voice. 1995; 9: 163-172
      1. Walden P. Perceptual Voice Qualities Database (PVQD). 2020;2. Mendeley Data, V2,

        • Morrison MD
        • Rammage LA.
        Muscle misuse voice disorders: description and classification.
        Acta Otolaryngol. 1993; 113: 428-434
        • Kreiman J
        • Shue YL
        • Chen G
        • et al.
        Variability in the relationships among voice quality, harmonic amplitudes, open quotient, and glottal area waveform shape in sustained phonation.
        J Acoust Soc Am. 2012; 132: 2625-2632
        • Hillenbrand J
        • Cleveland RA
        • Erickson RL.
        Acoustic correlates of breathy vocal quality.
        J Speech Hear Res. 1994; 37: 769-778
        • Klatl DH
        • Klati LC.
        Analysis, Synthesis, and Perception of Voice Quality Variations among Female and Male Talkers. 87. 1990
        • Granqvist S
        • Simberg S
        • Hertegård S
        • et al.
        Resonance tube phonation in water: high-speed imaging, electroglottographic and oral pressure observations of vocal fold vibrations - A pilot study.
        Logoped Phoniatr Vocol. 2015; (Published online)
        • Tyrmi J
        • Laukkanen AM.
        How stressful is “Deep Bubbling”?.
        J Voice. 2017; (Published online)
        • Horáček J
        • Radolf V
        • Laukkanen AM.
        Low frequency mechanical resonance of the vocal tract in vocal exercises that apply tubes.
        Biomed Signal Process Control. 2017; (Published online)
        • Dargin TC
        • Searl J
        Semi-occluded vocal tract exercises: aerodynamic and electroglottographic measurements in singers.
        J Voice. 2015; 29: 155-164
        • Guzman M
        • Jara R
        • Olavarria C
        • et al.
        Efficacy of water resistance therapy in subjects diagnosed with behavioral dysphonia: a randomized controlled trial.
        J Voice. 2017; 31: 385.e1-385.e10
        • Titze I.
        A short tutorial on sound level and loudness for voice.
        J Singing. 2013; 70: 191
        • Mathew MM
        • Bhat JS.
        Soft phonation index - A sensitive parameter?.
        Indian J Otolaryngolog Head Neck Surg. 2009; 61: 127-130
        • Meerschman I
        • Van Lierde K
        • Ketels J
        • Coppieters C
        • Claeys S
        • D’haeseleer E
        Effect of three semi-occluded vocal tract therapy programmes on the phonation of patients with dysphonia: lip trill, water-resistance therapy and straw phonation.
        International Journal of Language & Communication Disorders. 2018; 54: 50-61
        • Fadel CBX
        • Dassie-Leite AP
        • Santos RS
        • et al.
        Immediate effects of the semi-occluded vocal tract exercise with LaxVox® tube in singers.
        Codas. 2016; 28: 618-624
      2. elica Emygdio da Silva Antonetti A, da Silva Vitor J, Guzm an M, et al. Efficacy of a semi-occluded vocal tract exercises-therapeutic program in behavioral dysphonia: a randomized and blinded clinical trial. Published online 2020.

      3. Guzman M, Denizoglu I, Fridman D, Loncon C, Rivas C, García R, Morán C, Quezada C, Rodriguez L. Physiologic voice rehabilitation based on water resistance therapy with connected speech in subjects with vocal fatigue. J Voice. 2021. Published online.

        • Di Natale V
        • Cantarella G
        • Manfredi C
        • et al.
        Semioccluded vocal tract exercises improve self-perceived voice quality in healthy actors.
        J Voice. 2020; (Published online)
        • Alencar SAL de
        • Santos JP dos
        • Almeida LN
        • et al.
        Factorial analysis of the Brazilian version of the vocal tract discomfort scale in patients with dysphonia.
        J Voice. 2022; 36: 144.e11-144.e20