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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.

[straw OR tube OR semi-occluded vocal tract] AND [voice* OR phonation OR dysphoni*]. Limits abstracts, English Language, human.

Search Outcome

107 papers found of which 104 irrelevant.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Paes, Zambon, Yamasaki, Simberg and Behlau 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
Guzman, Higueras, Fincheira, Munoz, Guajardo, Dowdall (2013). Chile. 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
Costa, Costa, Oliveira and Behlau 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

Comment(s)

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.

Clinical 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

1. Paes, S.M., Zambon, F., Yamasaki, R., Simberg, S. and Behlau, M. Immediate effects of the Finnish resonance tube method on behavioural dysphonia. Journal of Voice 27 (6) 2013; Pp 717-722
2. 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. Logopedics Phoniatrics Vocology 38 2012; Pp 35-45
3. Costa, C.B., Costa, L.H.C., Oliveira, G. and Behlau, M. ). Immediate effects of the phonation into a straw exercise. Braz Journal of Otorhinolaryngology 77 (4). 2011; Pp. 461-465.