Semi-occluded vocal tract exercises in voice therapy
Date First Published:
November 10, 2014
Last Updated:
January 4, 2015
Report by:
Andrea Bromley, Speech and Language Therapist (Central Manchester Foundation Trust)
Search checked by:
Andrea Bromley, Central Manchester Foundation Trust
Three-Part Question:
In [adults with dysphonia], do [semi-occluded vocal tract exercises using a straw] improve [quality of voice]?
Clinical Scenario:
A patient is referred for voice therapy with dysphonia. There are many exercises available which will facilitate efficient phonation. Is the use of semi-occluded vocal tract exercises using a straw likely to lead to improvements in the quality of the person’s voice?
Search Strategy:
Medline 1946-present using the OVID interface.
Search Details:
[straw OR tube OR semi-occluded vocal tract] AND [voice* OR phonation OR dysphoni*]. Limits abstracts, English Language, human.
Outcome:
107 papers found of which 104 irrelevant.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Immediate effects of the Finnish resonance tube method on behavioural dysphonia. Paes, S.M., Zambon, F., Yamasaki, R., Simberg, S. and Behlau, M. 2013 Brazil and Finland | 25 female teachers with diagnosis of chronic behavioural dysphonia (5 years +) performed 10 tokens of sustained phonation into a straw in water. | Cohort study | Self- assessment (rating vocal comfort and voice quality as better, equal or worse than before exercises), auditory perceptual analysis (blinded rating of whether one recording was similar or better than the other) and acoustic evaluation (blinded visual analysis of instability of tracing, subharmonics, noise at high and low frequencies and series of harmonics). | Statistically significant result for self-rating (68% reported improved vocal comfort; 52% reported improved voice quality), auditory perceptual analysis of counting (60% rated as improved) and acoustic measures of instability, subharmonics, noise at high frequencies and fundamental frequency. No significance found on auditory perceptual rating of sustained vowel or on acoustic measures of noise at low frequencies and harmonic series. | No control group No sample size estimates No long-term effects measured Low sensitivity of rating scale |
| Immediate acoustic effects of straw phonation exercises in subjects with dysphonic voices. Guzman, M., Higueras, D., Fincheira, C., Munoz, D., Guajardo, C. and Dowdall, J. 2013 Chile | 41 primary school teachers with mild dysphonia (GRBAS = 1 for grade and breathiness) allocated to experimental group (four phonatory tasks with straw) or control group (four phonatory tasks with /a/). | Control trial | Acoustic measures using long-term average spectrum pre- and post-treatment, providing information about mode of phonation (L1 – L0 ratio), noise in the glottal source (ratio between 1-5khz and 5-8 khz) and spectral slope declination (alpha ratio). Speaking fundamental frequency also measured pre- and post-treatment. | Statistically significant result on all measures for experimental group except for speaking fundamental frequency. | No sample size estimates No long-term effects measured Only looks at mild dysphonia Diagnosis not defined Unclear methodology eg if randomly allocated |
| ). Immediate effects of the phonation into a straw exercise. Costa, C.B., Costa, L.H.C., Oliveira, G. and Behlau, M. 2011 Brazil | 23 individuals with benign vocal fold lesion (GL) 25 without performed sustained phonation into a straw for a period of one minute. | Cohort study | Self- assessment of voice (easier voice, better voice, easier and better voice, no difference), blinded perceptual auditory evaluation (mark the best segment or lack of difference in paired recordings), acoustic analysis (fundamental frequency, jitter and shimmer on sustained vowel) and laryngoscopy (constriction and phonatory gap). | Statistically significant result for self-rating of voice in the lesion group. No other significant results. | No sample size estimates No long-term effects measured Exercise only performed for one minute Low sensitivity of rating scale |
Author Commentary:
There is some evidence of the immediate benefits of phonation through a straw on voice quality, although studies are limited by methodology and small sample size. No studies have considered the long-term effects of the exercises and therefore there is no evidence to support or refute their use for long-term improvement. Further research is needed into the long-term effects before they can be used reliably as a main approach to treatment.
Bottom Line:
Evidence suggests that phonation into a straw exercises are likely to give patients some benefit in terms of voice quality, but they need to be provided in conjunction with other therapy to ensure functional long-term improvement is achieved.
References:
- Paes, S.M., Zambon, F., Yamasaki, R., Simberg, S. and Behlau, M. . Immediate effects of the Finnish resonance tube method on behavioural dysphonia.
- Guzman, M., Higueras, D., Fincheira, C., Munoz, D., Guajardo, C. and Dowdall, J. . Immediate acoustic effects of straw phonation exercises in subjects with dysphonic voices.
- Costa, C.B., Costa, L.H.C., Oliveira, G. and Behlau, M. . ). Immediate effects of the phonation into a straw exercise.