The Effectiveness of Manual Circumlaryngeal Therapy in Future Elite Professional Voice Users

Evelien D’haeseleer, Sofie Claeys, Kristiane Van Lierde

Department of Speech, Language, and Hearing Sciences Ghent University

Elite professional voice users

• Voice users where even a slight vocal difficulty causes serious consequences

• Musical performers (and students)– Special and vulnerable group for developing voice disorders

• High vocal load of the speaking and singing voice• High physical load• Not enough vocal and physical rest

• Future professional voice users– At risk for developing poor vocal quality (Timmermans et al. 2002)

• How can vocal quality be optimized?

Introduction

Manual Circumlaryngeal Therapy (MCT)

PURPOSE: Relaxation of the laryngeal and perilaryngeal musculature and optimal position of the larynx in the neck to improve phonation.

METHODS:– Hyoid bone

• The hyoid bone was encircled with the thumb and index finger, which were worked posteriorly until the tips of the major horns were felt.

– Thyroid cartilage• The same circular movement procedure beginning

from the thyroid notch and working posteriorly.• The posterior borders of the thyroid cartilage, were

located, and the procedure was repeated.– Total larynx

• With the fingers over the superior borders of the thyroid cartilage, the total larynx was worked downward and moved laterally at the same time.

Introduction

Effectiveness MCT

MCT is effective in patients with hyperfunctional voice disorders. (Roy et al., 1993; Roy et al., 1997; Van Lierde et al., 2004)

– Aronson (1990): manual therapy is the primary approach for patients with musculoskeletal tension disorders.

– MCT is more effective compared to breathing exercises in patients with muscle tension dysphonia. (Van Lierde et al., 2008)

What is the impact of MCT on the vocal quality of (healthy) musical performers (students)

Purpose of this study

Introduction

Methods

SUBJECTS

• 17 students bachelor’s program in music and performing arts (musical)– 6 men– 11 women

• Mean age: 24.4 year (range: 19-25 year)

• Perceptual normal voices (G0R0B0A0S0I0)

• Otorhinolaryngological evaluation: – Good general health, normal hearing, normal physiology and anatomy of the

larynx and the vocal cords (videostroboscopy, otoscopy and audiometry)

• 1 male student was excluded: organic voice disorder

• Vocal load– Mean hours of singing classes per day: 1.6 hours (SD: 0.57h)– Mean hours of acting classes per day: 3.1 hours (SD: 1.40h)

Methods

Methods

PROCEDURE

Pretest-posttest control group design

experimental group control groupn=8 n=7

- voice assessment - voice assessment- MCT 20 min - rest 20 min- voice assessment - voice assessment

Methods

Methods

OBJECTIVE VOICE ASSESSMENT

– Aerodynamic measurement• Maximal phonation time (s)

– Voice Range Profile• Highest intensity, Ihigh(dB)• Lowest intensity, Ilow (dB) • Highest frequency, Fhigh (Hz)• Lowest frequency, Flow (Hz)

– Acoustic analysis• F0

• Jitter (%)• Shimmer (%)• NHR

Methods

Dysphonia Severity Index

-5 +5

Methods

SUBJECTIVE VOICE ASSESSMENT

• Questionnaire:The subjects were asked whether

– the quality of the speaking and singing voice was worse, better, or the same as before the MCT.

– speaking was more difficult, easier, or the same as before.

– the vocal range was smaller, larger, or the same as before.

– the sensations in the throat and the larynx after MCT were painful, open, the same, other.

– the therapy itself was painful, not pleasant, no sensations, pleasant, other.

Methods

Statistical analysis

• Paired non parametric comparison before and after MCT– Experimental group

• Paired non parametric comparison before and after rest– Control group

• Wilcoxon Signed Rank test for two related samples

Methods

Results experimental group

MCT

pre postmedian Pc25 Pc75 median Pc25 Pc75 p-value

Aerodynamic measurement Maximal phonation time(s) 17.2 14.1 24.0 19.3 15.1 25.2 0.263

Vocal Range Lowest intensity (dB) 53.0 52.0 56.0 52.5 52.0 53.5 0.293

Highest intensity (dB) 111.0 1080 116.0 109.0 108.0 113.5 0.672

Lowest frequency (Hz) 116.5 77.8 138.6 123.7 77.8 138.6 1.000

Highest frequency (Hz) 1174.7 932.3 1480.0 1357.3 1053.5 1570.6 0.310

Akoestic analysis F0 (Hz) 222.2 166.8 234.8 237.1 113.1 240.4 0.612

jitter (%) 0.7 0.5 1.2 0.8 0.5 0.9 0.327

shimmer (%) 3.5 3.0 4.0 3.1 2.9 4.5 0.866

Noise to Harmonic Ratio 0.1 0.1 0.1 0.1 0.1 0.1 0.293

Dysphonia Severity Index 6.3 5.4 7.3 7.2 6.4 8.4 0.050

Results

Results control group

Rest

pre postmedian Pc25 Pc75 median Pc25 Pc75 p-value

Aerodynamic measurement Maximal phonation time(s) 18.5 17.5 25.2 18.0 17.0 24.7 0.799

Vocal Range Lowest intensity (dB) 53.0 50.0 53.0 54.0 53.0 55.0 0.071

Highest intensity (dB) 108.0 104.0 114.0 112.0 110.0 115.0 0.107

Lowest frequency (Hz) 138.6 77.8 146.8 130.8 77.8 146.8 0.581

Highest frequency (Hz) 1396.9 830.6 1568.0 1318.5 932.3 1568.0 0.500

Akoestic analysis F0 (Hz) 214.2 153.0 218.5 222.4 138.1 238.7 0.499

jitter (%) 0.6 0.3 0.9 0.6 0.3 1.1 0.735

shimmer (%) 3.3 2.3 3.5 3.0 2.6 3.1 0.237

Noise to Harmonic Ratio 0.1 0.1 0.1 0.1 0.1 0.1 0.498

Dysphonia Severity Index 6.8 6.0 9.1 6.5 5.1 8.8 0.237

Results

Results

Results

pre post2

3

4

5

6

7

8

MCT groupControl goup

p = 0.050

Dysphonia Severity Index

Results questionnaire

Results

Speaking and singing voice n % n % n % worse same better

Quality speaking voice 0/8 0% 5/8 62.5% 3/8 37.5%

Quality singing voice 0/8 0% 3/8 37.5% 5/8 62.5%more difficult same easier

Speaking 0/8 0% 5/8 62.5% 3/8 37.5%smaller same bigger

Vocal Range 0/8 0% 4/8 50% 4/8 50%no yes

Improvement of speaking or singing voice 2/8 25% 6/8 75%

Sensations larynx or throat n % n % n % painful open same

Larynx 0/8 0% 5/8 62.5% 3/8 37.5%

Throat 0/8 0% 5/8 62.5% 3/8 37.5%

Evaluation of MCT n % N % n % n %painful not pleasant no sensations pleasant

MCT 1/8 12.5% 3/8 37.5% 0/8 0% 4/8 50%

Discussion

• Hypothesis– MCT might maximize vocal capacities in this population as a result of a

maximal relaxation of the laryngeal and perilaryngeal musculature, and an optimal position of the larynx in the neck.

• Results: positive effect of MCT!– Increase of DSI (objective vocal quality)

• 6.3 7.2– Subjective experience

• 75%: improvement of the speaking or singing voice• 50%: not pleasant or painful therapy

• Caution– MCT can be carried out by ENT specialists and voice therapists with

profound knowledge of the intrinsic and extrinsic laryngeal musculature, and after practical training managed by a specialist in the field of laryngeal manipulation techniques.

Discussion

Discussion

• Musical students– Intensive training in acting, singing and dancing– Harmful life style habits– Risk for poor vocal quality

• Need for better guidance – Improve vocal hygiene (Timmermans et al. 2002)

– Effective techniques to maintain or improve vocal quality

• MCT– a possible technique for increasing or at least maintaining vocal quality

during rehearsals or before a musical performance.– when vocal capacities are diminished to obtain relaxation of the vocal

mechanism and consequently improve vocal quality.

• HOWEVER• Further research is necessary

Discussion

Thank you for your attention