Laryngeal and Pharyngeal Activity During

Semioccluded Vocal Tract Postures in Subjects

Diagnosed With Hyperfunctional Dysphonia
~ oz, and kJulia Gerhard, *xSantiago, yValparaiso, zVi~na del
*Marco Guzman, Christian Castro, Alba Testart, Daniel Mun

Mar, Chile, and kMiami, Florida

Summary: High vertical laryngeal position (VLP), pharyngeal constriction, and laryngeal compression are common
features associated with hyperfunctional voice disorders. The present study aimed to observe the effect on these variables of different semioccluded vocal tract postures in 20 subjects diagnosed with hyperfunctional dysphonia. During
observation with flexible endoscope, each participant was asked to produce eight different semioccluded exercises: lip
trills, hand-over-mouth technique, phonation into four different tubes, and tube phonation into water using two different
depth levels. Participants were required to produce each exercise at three loudness levels: habitual, soft, and loud. To
determine the VLP, anterior-to-posterior (A-P) compression, and pharyngeal width, a human evaluation test with three
blinded laryngologists was conducted. Judges rated the three endoscopic variables using a five-point Likert scale. An
intraclass correlation coefficient to assess intrarater and interrater agreement was performed. A multivariate linear regression model considering VLP, pharyngeal width, and A-P laryngeal compression as outcomes and phonatory tasks
and intensity levels as predictive variables were carried out. Correlation analysis between variables was also conducted.
Results indicate that all variables differ significantly. Therefore, VLP, A-P constriction, and pharyngeal width changed
differently throughout the eight semioccluded postures. All semioccluded techniques produced a lower VLP, narrower
aryepiglottic opening, and a wider pharynx than resting position. More prominent changes were obtained with a tube
into the water and narrow tube into the air. VLP significantly correlated with pharyngeal width and A-P laryngeal compression. Moreover, pharyngeal width significantly correlated with A-P laryngeal compression.
Key Words: SemiocclusionVocal tractVoice therapyHyperfunctionDysphoniaAryepiglottic narrowingVertical
laryngeal positionPharyngeal width.

INTRODUCTION
It is generally agreed among clinicians and voice scientists that
the vertical laryngeal position (VLP) is an important aspect of
voice production in both normal and pathological voices.1,2 It
seems that several factors affect the VLP, such as phonetic
features,3,4 lung volume,5 voice technique,6,7 pitch control,6 respiratory technique,8 and vocal loudness.9
A high laryngeal position is commonly associated with voices
that have a strong component of muscle tension, especially in
patients diagnosed with hyperfunctional voice disorders. Commonly, the abnormally high tension in extrinsic laryngeal muscles may cause a high position of the larynx.1012 Therefore,
a lowering of the elevated larynx is usually an important goal
in clinical voice therapy and classical singing pedagogy.1,1319
Several vocal exercises have been reported as useful
therapeutic and training tools to lower the larynx. The yawnsigh technique is one of the most popular among voice pathologists and voice teachers.14 Other exercises are the prolonged
consonant /b:/,15 soft and aspirate vocal onset,16 and laryngeal
manipulation.1719
Accepted for publication May 17, 2013.
From the *School of Communication Sciences, University of Chile, Santiago, Chile;
ySchool of Communication Sciences, University of Valparaiso, Valparaiso, Chile;
zSchool of Communication Sciences, Universidad del Mar, Vi~na del Mar, Chile;
xDepartment of Network Management, Barros Luco-Trudeau Hospital, Santiago, Chile;
and the kDepartment of Otolaryngology, University of Miami, Miami, Florida.
Address correspondence and reprint requests to Marco Guzman, School of Communication Sciences, University of Chile, Avenida Independencia 1027, Santiago, Chile. E-mail:
guzmanvoz@gmail.com
Journal of Voice, Vol. 27, No. 6, pp. 709-716
0892-1997/$36.00
2013 The Voice Foundation
http://dx.doi.org/10.1016/j.jvoice.2013.05.007

VLP has both acoustic and physiological implications. An

upward movement of the larynx from its resting position
shortens vocal tract length, which raises all formant frequencies;
this, in turn, produces a brighter vocal quality.20,21 The low
position of the larynx produces the opposite acoustic effect.
The VLP also has important effects on the biomechanical
properties of the vocal folds. A high VLP stiffens the vocal
fold tissues, therefore increasing fundamental frequency and
potentially changing the folds vibratory pattern. Furthermore,
high VLP usually facilitates a tight vocal fold adduction
as part of the valving laryngeal function for airway
protection.20,21 Moreover, Titze22 reported that vocal folds are
likely to be thicker when the larynx is lowered. Thus, the cover
of vocal folds loosens and the medial surfaces make a better glottal closure. When this occurs, a greater maximum flow declination rate is produced, which contributes to the increased vocal
intensity without additional vocal effort.
Another common feature treated by voice therapists in
patients diagnosed with muscle tension is the relaxation and
opening of the pharyngeal area. This is also an important goal
of singing pedagogy. Exercises to produce an open throat
have been one of the most used tools to produce freedom or
lack of tension in the area of the throat, resulting in a lack of
constriction and a better voice quality in both normal and pathological voices.13,23,24 Most teachers include the use of the
open throat technique as an important feature in singing
training, especially in classical singing. The purpose of these
types of exercises is described by voice trainers to be a way
of maximizing pharyngeal space and/or achieving abduction
of the ventricular folds.13 Titze25 as well as Titze and Story26

710
described a wide pharynx as an acoustic enhancement to the
first formant and to the overall sound. An open throat production has perceptually been described as a rounded, free, effortless, and warm sound.27
Supraglottic activity refers to the movements and configurations of structures above the vocal folds. There are two types
of supraglottic activity: (1) anterior-to-posterior (A-P) laryngeal
compression (aryepiglottic narrowing), which occurs when the
arytenoid cartilages approximate the petiole of the epiglottis
and (2) medial constriction, which refers to adduction of the
false vocal folds.28,29 Supraglottic activity has been commonly
classified as a sign of nonorganic hyperfunctional dysphonia by
clinicians.30 In addition, for many years, the development of
several benign lesions on the vocal fold surface has been
assumed to be related to hyperfunctional behavior or phonotrauma.31 On the other hand, some studies show that supraglottic
activity could be present in subjects with normal voice.28,29,32
In fact, both A-P and medial compression have been found
to be normal and even desirable laryngeal behaviors in
singing7,3336 and speaking among professional voice users.37
The present study aimed to observe and compare the effect of
eight semioccluded vocal tract postures on VLP, A-P laryngeal
compression, and pharyngeal width in a group of subjects diagnosed with hyperfunctional dysphonia.
METHODS
Participants
This study was approved by the research ethics committee at the
School of Communication Disorders of the University of Valparaiso, Chile. Informed consent was obtained from 28 adult
subjects (19 women and 9 men). The average age of this subject
set was 26 years, with a range of 2028 years old. Inclusion criteria for this study included (1) no previous voice therapy or
voice training and (2) diagnosis of hyperfunctional dysphonia
without any vocal fold lesions. Individuals with a history of
smoking were excluded from this study. Although 28 subjects
were recruited, seven of them did not meet the inclusion criteria. Therefore, only 21 were included in the analysis. Participants were asked to undergo flexible laryngoscopy to
corroborate laryngeal diagnosis and to perform the phonatory
tasks. The initial diagnosis was made by a laryngologist with
more than 20 years of experience in voice disorders. All participants reported at least 1 year of voice problems.
Laryngoscopic procedure
At the beginning of the examination, participants were asked to
sit upright in a comfortable chair. Assessment of the laryngeal
and pharyngeal activity was carried out through endoscopic examination with a flexible fiberoptic endoscope (Olympus ENF
type p4; Olympus, Center Valley, PA) connected to a video camera (Sony DCX-LS1 Sintek; Sony Corporation, New York, NY)
and a Richard Wolf LP 4200 light source (Richard Wolf Medical Instrument Corporation, Vernon Hills, IL). Analog images
were digitalized with Pinnacle Studio HD 10 software (Corel
Corporation, Fremont, CA), and views were monitored on
a color television monitor (Sony SSM-20L120). All examina-

Journal of Voice, Vol. 27, No. 6, 2013

tions were performed without topical nasal anesthesia. The flexible endoscope was placed directly below the tip of the uvula,
allowing a full view of the pharynx and larynx. This placement
was fixed by securing the fiberscope against the alar cartilage of
the nose with the laryngologists finger. A steady placement of
the fiberscope is crucial because observation of laryngeal height
adjustments and other laryngeal configurations can be affected
by movement of the fiberscope. For the purposes of this study,
three aspects were observed during laryngoscopic procedure:
VLP, pharyngeal width, and A-P laryngeal compression.
Phonatory tasks
During the observation with the flexible endoscope, each participant was required to produce four different semioccluded vocal
tract exercises at habitual speaking pitch: lip trill, hand-overmouth technique, tube phonation into air, and tube phonation
into water. All subjects performed these phonatory tasks twice.
Participants were asked to perform tasks at their habitual speaking pitch to avoid variation (the effect of pitch on) in VLPs. Participants were asked to produce each exercise at three loudness
levels: soft, moderate, and loud. Tube into water exercises were
performed at only moderate loudness. The tube phonation tasks
were performed using four different types of plastic commercial drinking (wide) and stirring (narrow) straws. Each participant was instructed to hold the straw with one hand, straight out
from the mouth. The straw was maintained a few millimeters
between the rounded lips, so that no air would leak from the
mouth; the free end was kept either in the air or submerged under the water as an extension of the vocal tract. Careful control
of pitch throughout the entire sequence was performed. An
electronic keyboard was used to give and control the pitch,
which was monitored auditorily. Pitch control is relevant because it may influence both laryngeal and pharyngeal activities.
Each phonatory task was produced for a minimum of 7 seconds,
and subjects were required to breathe normally between tasks to
avoid the effect of lung volume on the laryngeal height. Before
each semioccluded task, participants returned to a phonatory
resting position to obtain baseline measures.
Each complete assessment session was accomplished in approximately 15 minutes with the following protocol:
1. Phonation into a long-wide tube (6 mm of inner diameter
and 20 cm in length).
2. Phonation into a long-narrow tube (3 mm of inner diameter and 20 cm in length).
3. Phonation into a short-wide tube (6 mm of inner diameter
and 10 cm in length).
4. Phonation into a short-narrow tube (3 mm of inner diameter and 10 cm in length).
5. Phonation into a long-wide tube submerged 3 cm below
the water surface.
6. Phonation into a long-wide tube submerged 10 cm below
the water surface.
7. Phonation using the hand-over-mouth technique.
8. Phonation with lip trill.
The order of the tasks in the protocol was not randomized.

Marco Guzman, et al

Laryngeal and Pharyngeal Activity During Semioccluded Exercises

Visual evaluation
To determine the VLP, A-P compression, and pharyngeal width,
we conducted a human evaluation test with three blinded judges
(2 men, 1 woman; mean age of 46 years with a range of 42
50 years). All judges were laryngologists with more than 4 years
of experience in voice disorders. All audio signals were removed from video samples before performing the assessment
to avoid the possible effect of voice quality on the judges ratings. To standardize the rating parameters and rating scales, the
three judges participated in a 1-hour training session in videolaryngoscopic examinations. Video samples from each subject
were played to the judges, and they were instructed to rate the
three endoscopic variables using a five-point Likert scale; for
VLP (1 very high and 5 very low), A-P laryngeal compression (1 very opened and 5 very narrow), and pharyngeal
width (1 very narrow and 5 very wide). The evaluation
was performed in a quiet room. Ratings were completed in
two sessions by all the raters. Each session lasted no more
than 1 hour. All raters reported normal or corrected-to-normal
vision. Fifteen percent of the samples were randomly repeated
to assess the intrarater reliability. Judges were not aware of
these repetitions.
Statistical analysis
Descriptive statistics were calculated for the variables, including mean and standard deviation. A multivariate linear regression model was used to obtain an intraclass correlation
coefficient (ICC) to assess the judges reliability (intrarater
and interrater agreement) controlled by phonatory task and vocal loudness. Then, another multivariate linear regression
model considering VLP, pharyngeal width, and A-P laryngeal
compression as outcomes as well as phonatory tasks and its intensity as predictive variables (and its interactions if exist) was
performed. Simple correlation analysis using Spearman rho between VLP, pharyngeal width, and A-P laryngeal constriction
was also conducted. One-way analysis of variance for test differences between phonatory task scores was used. The analysis
was performed using Stata 12.1 (StataCorp LP, College Station,
TX) software. An alpha of .05 was used for the statistical
procedures.
RESULTS
Table 1 shows the results from the intrarater reliability analysis.
A good intrarater concordance was demonstrated for each
judge. Moreover, the three blinded judges obtained a high
agreement (interrater reliability) (ICC 0.79 [0.660.87],
P < 0.0001).
Table 2 and Figure 1 display the comparison between score
averages by phonatory task for each variable (outcome).
P values indicate that all variables were found to have a significant effect, and all of them differ significantly from each other
(P < 0.0001). Therefore, VLP, A-P laryngeal compression, and
pharyngeal width changed differently throughout the eight
semioccluded postures.
Results from the multivariate linear regression model including VLP, pharyngeal width, and A-P laryngeal constriction as

711

TABLE 1.
Intrarater Reliability Analysis
Judge
1
2
3

ICC (95% Confidence

Interval)

P Value

0.71 (0.610.86)
0.78 (0.670.88)
0.65 (0.540.79)

<0.0001
<0.0001
<0.0001

outcomes as well as phonatory task and its intensity as predictive variables (and its interactions if they exist) are shown in
Table 3.
VLP significantly correlates with pharyngeal width
(rho 0.578; P < 0.0001) and A-P laryngeal constriction
(rho 0.3364; P < 0.0001). Furthermore, pharyngeal width significantly correlates with A-P laryngeal constriction
(rho 0.18; P 0.001).
DISCUSSION
The present study aimed to observe the effect of eight semioccluded vocal tract postures on VLP, A-P laryngeal compression,
and pharyngeal width in a group of subjects diagnosed with hyperfunctional dysphonia. This is the first study designed to compare the effect of a large number of semioccluded vocal
exercises and different loudness levels on pharyngeal and laryngeal activities. Result revealed that the effect on these variables
is statistically significant throughout all phonatory tasks.
All semioccluded postures produced a decrease in VLP compared with the resting position. Phonation with tube into the
water (10 and 3 cm below the surface) and phonation into
a long-narrow tube produced the three lowest VLPs. Interestingly, the same three phonatory tasks caused the widest pharynx
and the narrowest A-P laryngeal compression. In fact, the correlation analysis demonstrated a high correlation between all
these dependent variables.
Sovijarvi et al38 stated that one of the most relevant effects of
tube phonation is the lowering of the larynx. The degree of this
effect would be related to the length of the tube.3941 The same
author pointed out that the goal is not necessarily to reach a very
low larynx but to avoid a high VLP, especially in subjects with
hyperfunctional laryngeal activity.42
Earlier investigations have demonstrated similar effects of
tube phonation on VLP. In a computerized tomography study,
Guzman et al43 reported lowering of the larynx during both
glass resonance tube and stirring straw phonation. This change
remained during vowel production after tube and straw. In a videofluorographic and dual-channel electroglottographic registration, Laukkanen et al44 found a lower VLP compared
with the resting position during other semioccluded vocal tract
postures. The opposite effect of tube phonation on VLP has also
been demonstrated.45,46 Furthermore, two recent magnetic
resonance imaging studies reported no changes on the VLP
during phonation into a resonance tube and during voiced
plosive consonants.47,48
It is important to highlight that no previous studies have reported the effect of semioccluded postures on VLP in subjects

712
<0.0001
<0.0001
<0.0001
3.47 (0.64)
3.19 (0.56)
3.38 (0.55)
3.73 (0.62)
3.66 (0.67)
3.19 (0.73)
4.80 (0.40)
4.66 (0.57)
4.04 (0.92)
4.28 (0.56)
4.19 (0.51)
3.80 (0.74)
4.17 (0.58)
3.88 (0.59)
3.49 (0.73)
3.71 (0.55)
3.34 (0.57)
3.23 (0.55)
3.96 (0.67)
3.63 (0.65)
3.25 (0.67)
VLP
Pharyngeal width
A-P laryngeal compression

4.38 (0.65)
4.04 (0.79)
3.52 (0.64)

Short-Narrow
Tube
Short-Wide
Tube
Long-Narrow
Tube
Long-Wide
Tube
Variable

Phonatory Task (Mean, Standard Deviation)

TABLE 2.
Comparison Between Score Averages by Phonatory Task for Each Variable

Tube Into the

Water (3 cm)

Tube Into the

Water (10 cm)

Hand Over
Mouth

Lip Trill

P Value

Journal of Voice, Vol. 27, No. 6, 2013

diagnosed with nonorganic hyperfunctional dysphonia. A

high VLP is commonly presented in patients with this vocal
condition.1012 Because VLP significantly decreased in our
participants, it can be concluded that semioccluded postures,
especially tube submerged into the water and phonation into
long-narrow tube (stirring straw), are suitable therapeutic tools
for people with high VLP because of laryngeal muscle tension.
Muscle tension may be reflected in the pharyngeal activity as
well, more specifically in pharyngeal narrowing. Findings from
the present study revealed that all phonatory tasks produced
a widening of the pharynx during exercising. Earlier studies
have demonstrated similar outcomes on pharyngeal configuration.4749 Several changes were observed during both glass
resonance tube and narrow straw phonation in a recent
study.43 The lower pharynx area, middle pharyngeal region,
and A-P width of the hypopharynx increased during exercising
compared with vowel phonation before the exercises. All these
changes were larger during straw than tube phonation. Moreover, in a computed tomography and finite-element modeling
investigation, the most dominant change in the vocal tract during phonation into the tube was caused by expansion of the
cross-sectional area of the oropharynx.49 An increase in the
area of the junction between the pyriform sinuses and epilaryngeal tube was also observed. Hence, lengthening of the vocal
tract may also have a positive effect on pharyngeal configuration in patients with hyperfunction. It may also be used as a vocal training exercise in normal individuals.
Two possible explanations could be reasonable for the effect
on VLP and pharyngeal width of phonation with a tube submerged under the water and a long-narrow tube (stirring straw).
First, oral pressure increases during these types of exercises.43,50 In a previous study, acoustic impedance and mean
supraglottal resistance were raised by phonating into different
tubes (different in length and inner diameter) in the air and
submerged under the water. The results showed that the oral
pressure is higher when phonating into narrow straws (stirring
straws) than wide straws (drinking straws) and even higher
when straws are submerged under the water. Furthermore, the
deeper the straw is under the water the higher the oral
pressure.50 These findings are in line with the results reported
by Titze.51 Guzman et al43 also reported increased oral pressure
during resonance tube and stirring straw phonation, being
greater in the latter. Interestingly, in the present study, the lowest VLP and widest pharynx were observed during the most resistive phonatory tasks: phonation into a straw submerged
under the water (3 and 10 cm) and phonation into a longnarrow tube (stirring straw). The other semioccluded postures
also produced the same effect but with a lower degree. The increased oral pressure during semioccluded exercises may have
directly pushed the larynx down and the pharyngeal walls laterally. Therefore, the first possible explanation would be a mechanical effect. The second explanation of the effect on VLP
and pharyngeal widening of semiocclusions is the muscle relaxation. The pushing effect accomplished by oral pressure may
produce a relaxation of the laryngeal and pharyngeal musculature, and this in turn may have produced a lowering of the larynx and widening of the pharynx.

Marco Guzman, et al

Laryngeal and Pharyngeal Activity During Semioccluded Exercises

Another interesting result from the present study was the aryepiglottic narrowing (A-P compression) found during all phonatory tasks. As occurred for the VLP and pharyngeal width,
the A-P compression was also more prominent during phonation with a tube submerged under the water (3 and 10 cm)
and during phonation with a long-narrow tube. Aryepigottic
narrowing or A-P laryngeal compression has been described
as both a sign of laryngeal hyperfunction28,29 and also as
a good and desirable feature in voice performers.7,3336
Sundberg7 reported that the aryepiglottic narrowing contributes
to the formation of the singers formant, a cluster of the third,
fourth, and fifth formants. This acoustic characteristic, typical
in trained singers, may help singers obtain a louder and brighter
voice quality because of a high concentration of acoustic energy
around 3 kHz. These findings were later confirmed by Titze and
Story.26
It not surprising that in the present study, VLP and A-P laryngeal compression were correlated. In this regard, Sundberg7 has
suggested that aryepiglottic narrowing can be reached by lowering of the larynx. According to the author, a low VLP is a way
to obtain a high ratio between the cross-sectional area of the low
pharynx and the epilaryngeal tube opening, which is the necessary setting to produce the singers formant cluster. Nevertheless, this is not the only way to reach the high ratio. Earlier
investigations have demonstrated that a spectral prominence
near 3 kHz could also be obtained by other vocal tract
strategies.37,47,48
A high correlation between pharyngeal width and A-P laryngeal compression was demonstrated in the present study as
well. This means that when the pharynx widened, there was
also a narrowing of the aryepiglottic sphincter. A greater ratio
of inlet to the pharynx over the outlet of the epilarynx tube
has previously been reported using magnetic resonance imaging and computerized tomography examinations when using artificial lengthening of the vocal tract.43,47,48 This increased ratio
would help to the formation of the singer/speakers formant.7,25

713

Related to this, in the three previous cited studies where

a greater ratio was obtained,43,47,48 a more evident spectral
prominence around 2.5 kHz (singers formant) was also
reported. Therefore, it is feasible to assume that vocal tract
semiocclusions may contribute to a high concentration of
spectral energy at the singers formant region because of an
increment of the ratio between pharyngeal and epilaryngeal
tube openings.
According to Titze and Story,26 when a narrowed epilarynx
(produced by an aryepiglottic narrowing) is combined with
a wide pharynx, the acoustic load of the vocal tract is inertive
for all possible values of fundamental frequencies. This produces strong interactions between the source and the filter. Specifically, the inertance of the vocal tract facilitates vocal fold
vibration by lowering the oscillation threshold pressure. This
effect may also be important for people with hyperfunctional
dysphonia.
In the present study, all dependent variables demonstrated the
greatest degree of change (P < 0.001) when phonating with loud
voice. No significant changes were observed during soft and
moderate loudness for pharyngeal width and A-P laryngeal
compression. For VLP, all loudness levels caused a significantly
lower larynx. However, as mentioned previously, the greatest
change was seen during loud voice production. This is an interesting result that could be related to the degree of oral pressure
produced during artificial lengthening and occlusions of the vocal tract. Therefore, this independent variable should be considered when using these types of exercises to modify the
laryngeal and pharyngeal activities. In an earlier study, Yanagisawa et al34 found similar results with regard to the effect of
loudness on supraglottic activity. The authors reported that
more aryepiglottic narrowing was obtained when loudness level
increased across different singing voice qualities.
Because the order of the tasks in the protocol was not randomized, one could suspect that in fact only the first task had
an effect, which then persisted across the other tasks. However,

FIGURE 1. Comparison between score averages by phonatory task for each variable.

714
TABLE 3.
Multivariate Linear Regression Model Considering VLP, Pharyngeal Width, and A-P Laryngeal Constriction as Outcomes; and Phonatory Task and Its Intensity
as Predictive Variables
VLP

Variables

Coefficients (95%
Confidence Interval)

P Value

Variables

Coefficients (95%
Confidence Interval)

A-P Laryngeal Constriction

P Value

0.21 (0.11, 0.28)

0.23 (0.09, 0.38)
0.38 (0.24, 0.53)

3.11
3.18
5.20

0.007
0.002
<0.001

Soft
Habitual
Loud

0.11 (0.05, 0.18)

0.14 (0.01, 0.29)
0.41 (0.25, 0.56)

1.27
1.84
5.30

0.091 (NS)
0.067 (NS)
<0.001

0.37 (0.19, 0.55)

3.60

<0.001

0.57 (0.25, 0.90)

3.69

<0.001

0.41 (0.20, 0.62)

3.90

<0.001

0.41 (0.19, 0.62)

3.75

<0.001

2.40

0.017

2.60

0.010

0.20 (0.001, 0.41)

1.95

0.052

0.25 (0.03, 0.47)

2.31

0.022

0.28 (0.017, 0.59)

1.85

0.065 (NS)

0.59 (0.27, 0.91)

3.69

<0.001

0.81 (0.50, 1.11)

5.21

<0.001

1.07 (0.75, 1.39)

6.63

<0.001

0.23 (0.44, 0.03)

2.25

0.025

0.03 (0.18, 0.24)

0.29

0.773 (NS)

0.49 (0.70, 0.28)

4.65

<0.001

Long-wide
tube
Long-narrow
tube
Short-wide
tube
Short-narrow
tube
Tube into the
water
(3 cm)
Tube into the
water
(10 cm)
Hand over
mouth
Lip trill

0.25 (0.20, 0.04)

Abbreviation: NS, not significant.

0.28 (0.50, 0.06)

0.44 (0.66, 0.22)

4.04

<0.001

Variables

Coefficients (95%
Confidence
Interval)

P Value

Soft
Habitual
Loud

0.10 (0.08, 0.17)

0.11 (0.04, 0.28)
0.30 (0.13, 0.46)

1.13
1.42
3.60

0.238 (NS)
0.157 (NS)
<0.001

Long-wide
tube
Long-narrow
tube
Short-wide
tube
Short-narrow
tube
Tube into the
water
(3 cm)
Tube into the
water
(10 cm)
Hand over
mouth
Lip trill

0.78 (0.45, 1.11)

4.62

<0.001

0.26 (0.03, 0.50)

2.27

0.023

0.01 (0.24, 0.21)

0.13

0.23 (0.004, 0.47)

2.01

0.045

0.57 (0.23, 0.91)

3.30

0.001

0.81 (0.47, 1.15)

4.67

<0.001

0.894 (NS)

0.06 (0.29, 0.16)

0.54

0.593 (NS)

0.12 (0.10, 0.36)

1.07

0.285 (NS)

Journal of Voice, Vol. 27, No. 6, 2013

Intensity
Soft
Habitual
Loud
Phonatory task
Long-wide
tube
Long-narrow
tube
Short-wide
tube
Short-narrow
tube
Tube into the
water
(3 cm)
Tube into the
water
(10 cm)
Hand over
mouth
Lip trill

Pharyngeal Width

Marco Guzman, et al

Laryngeal and Pharyngeal Activity During Semioccluded Exercises

this is unlikely because of the degree of the effected change

throughout the sequence in all participants. For instance, the
task that showed the most prominent effect in all variables
(tube submerged 10 cm into the water) was performed sixth
in the sequence. Additionally, lip trills, which were carried
out at the end of the sequence, showed the lowest degree of
change in two of the three independent variables.
The present study may have some limitations. First, all the
participants were diagnosed with hyperfunctional dysphonia,
and none of the subjects with hypofunctional dysphonia were
included. A different effect could be likely between these two
groups. Second, only the short-term effect was assessed. Possible long-term changes remain unknown. Finally, quantitative
imaging may be able to provide more accurate information regarding the VLP, pharyngeal width, and A-P compression during semioccluded postures.
CONCLUSION
VLP, A-P laryngeal compression, and pharyngeal width can be
modified by semioccluded vocal tract exercises in subjects diagnosed with nonorganic hyperfunctional dysphonia. A low larynx, narrow aryepiglottic opening, and wide pharynx may be
reached by using these types of exercises. Phonation into
a tube submerged under the water and a stirring straw produce
more prominent changes than the other examined semioccluded
postures. Loud voice productions also demonstrated a greater
degree of change than soft and moderate loudness levels. Two
possible explanations arise for these findings: an increase in
oral pressure (mechanical effect) and/or a relaxation of the laryngeal and pharyngeal musculature because of semiocclusions. The observed effect is only short term, and the
retention of the effect remains unknown.
REFERENCES
1. Aronson A. Clinical Voice Disorders. An Interdisciplinary Approach. New
York, NY: Thieme Medical Publishers; 1985.
2. Colton R, Casper J. Understanding Voice Problems. A Physiological Perspective for Diagnosis and Treatment. Baltimore, MD: Lippincott Williams
& Wilkins; 1990.
3. Ewan WG, Krones R. Measuring larynx movement using the thryroumbrometer. J Phonetics. 1974;2:327335.
4. Riordan CJ. Control of vocal-tract length in speech. J Acoust Soc Am. 1977;
62:9981002.
5. Iwarsson J, Sundberg J. Effects of lung volume on vertical larynx position
during phonation. J Voice. 1998;12:159165.
6. Shipp T, Izdebski K. Vocal frequency and vertical larynx positioning by
singers and nonsingers. J Acoust Soc Am. 1975;58:11041106.
7. Sundberg J. Articulatory interpretations of the singing formant. J Acoust
Soc Am. 1974;55:838844.
8. Iwarsson J. Effects of inhalatory abdominal wall movement on vertical laryngeal position during phonation. J Voice. 2001;15:384394.
9. Shipp T. Effects of vocal frequency and effort on vertical laryngeal position.
J Res Singing. 1984;6:15.
10. Angsuwarangsee T, Morrison M. Extrinsic laryngeal muscular tension in
patients with voice disorders. J Voice. 2002;16:333343.
11. Rubin JS, Blake E, Mathieson L. Musculoskeletal patterns in patients with
voice disorders. J Voice. 2007;21:477484.
12. Lowell SY, Kelley RT, Colton RH, Smith PB, Portnoy JE. Position of the
hyoid and larynx in people with muscle tension dysphonia. Laryngoscope.
2012;122:370377.

715

13. Boone DR. The Voice and Voice Therapy. Englewood Cliffs, NJ: Prentice
Hall; 1977.
14. Boone DR, McFarlane SC. A critical view of the yawn-sigh as a voice therapy technique. J Voice. 1993;7:7580.
15. Elliot N, Sundberg J, Gramming P. Physiological aspects of a vocal exercise. J Voice. 1997;11:171177.
16. Casper JK, Colton RH, Woo P, Brewer D. Physiological characteristics of
selected voice therapy techniques: a preliminary research note. J Voice.
1992;1:131141.
17. Van Lierde KM, De Bodt M, Dhaeseleer E, Wuyts F, Claeys S. The treatment of muscle tension dysphonia: a comparison of two treatment techniques by means of an objective multiparameter approach. J Voice. 2010;
24:294301.
18. Mathieson L, Hirani SP, Epstein R, Baken RJ, Wood G, Rubin JS. Laryngeal manual therapy: a preliminary study to examine its treatment effects
in the management of muscle tension dysphonia. J Voice. 2009;23:
353366.
19. Roy N, Leeper HA. Effects of the manual laryngeal musculoskeletal tension reduction technique as a treatment for functional voice disorders: perceptual and acoustic measures. J Voice. 1993;7:242249.
20. Shipp T. Vertical laryngeal position: research findings and their relationship
for singers. J Voice. 1987;1:217219.
21. Sundberg J, Nordstrom P-E. Raised and lowered larynxthe effect on
vowel formant frequencies. STL-QPSR. 1976;17:3539.
22. Titze IR. Raised versus lowered larynx singing. NATS J. 1993;50:37.
23. Mitchell HF, Kenny DT, Ryan M, Davis PJ. Defining open throat through
content analysis of experts pedagogical practices. Logoped Phoniatr
Vocol. 2003;28:167180.
24. Mitchell HF, Kenny DT. The effects of open throat technique on long term
average spectra (LTAS) of female classical voices. Logoped Phoniatr
Vocol. 2004;29:99118.
25. Titze I. Voice research: the wide pharynx. J Singing. 1998;55:2728.
26. Titze IR, Story BH. Acoustic interactions of the voice source with the lower
vocal tract. J Acoust Soc Am. 1997;101:22342243.
27. Ware C. Basics of Vocal Pedagogy: The Foundations and Process of Singing. New York, NY: McGraw-Hill; 1998.
28. Stager SV, Bielamowicz S, Gupta A, Marullo S, Regnell JR, Barkmeier J.
Quantification of static and dynamic supraglottic activity. J Speech Lang
Hear Res. 2001;44:12451256.
29. Stager S, Bielamowicz S, Regnell J, Gupta A, Brakmeier J. Supraglottic activity: evidence of hyperfunction or laryngeal articulation? J Speech Lang
Hear Res. 2000;43:229238.
30. Behrman A, Dahl L, Abramson A, Schutte H. Anterior-posterior and medial compression of the supraglottis: signs of nonorganic dysphonia or normal postures? J Voice. 2003;17:403410.
31. Hillman RE, Gress C, Hargrave J, Walsh M, Bunting G. The efficacy of
speech-language pathology intervention: voice disorders. Semin Speech
Lang. 1990;11:297310.
32. Sama A, Carding PN, Price S, Kelly P, Wilson JA. The clinical features of
functional dysphonia. Laryngoscope. 2001;111:458463.
33. Lawrence V. Laryngological observations on belting. J Res Singing. 1979;
2:2628.
34. Yanagisawa E, Estill J, Kmucha S, Leder S. The contribution of aryepiglottic constriction to ringing voice qualitya videolaryngoscopic study
with acoustic analysis. J Voice. 1989;3:342350.
35. Pershall KE, Boone DR. Supraglottic contribution to voice quality. J Voice.
1987;1:186190.
36. Hanayama E, Camargo Z, Tsuji D, Pinho S. Metallic voice: physiological
and acoustic features. J Voice. 2009;23:6270.
37. Leino T, Laukkanen AM, Radolf V. Formation of the actors/speakers formant: a study applying spectrum analysis and computer modeling. J Voice.
2011;25:150158.
38. Sovijarvi A, Hayrinen R, Orden-Pannila M, Syvanen M. Aanifysiologisten
Kuntoutusharjoitusten Ohjeita. [Instructions for voice exercises]. Helsinki,
Finland: Publications of Suomen Puheopisto; 1989.
39. Sovijarvi A. Nya metoder vid behandlingen av rostrubbningar. Nordisk Tidskrift for Tale og Stemme. 1969;3:121131.

716
40. Simberg S, Laine A. The resonance tube method in voice therapy: description and practical implementations. Logoped Phoniatr Vocol. 2007;32:
165170.
41. Sovijarvi A. Die Bestimmung der Stimmkategorien mittels Resonanzrohren. Int Kongr Phon Wiss. 1965;8:532535.
42. Sovijarvi A. Adnifysiologiasta ja artikulaatiotekniikasta. [On Voice Physiology and Articulatory Technique] [in Finnish]. Helsinki, Finland: Department of Phonetics, University of Helsinki; 1966.

43. Guzman M, Laukkanen A-M, Krupa P, Horacek J, Svec
J, Geneid A. Vocal
tract and glottal function during and after vocal exercising with resonance
tube and straw. J Voice. 2013;27:523.
44. Laukkanen AM, Takalo R, Vilkman E, Nummenranta J, Lipponen T. Simultaneous videofluorographic and dual-channel electroglottographic registration of the vertical laryngeal position in various phonatory tasks. J Voice.
1999;13:6071.
45. Laukkanen A-M, Lindholm P, Vilkman E, Haataja K, Alku P. A physiological and acoustic study on voiced bilabial fricative /:/ as a vocal exercise.
J Voice. 1996;10:6777.

Journal of Voice, Vol. 27, No. 6, 2013

46. Laukkanen A, Titze I, Hoffman H, Finnegan E. Effects of a semi-occluded
vocal tract on laryngeal muscle activity and glottal adduction in a single female subject. Folia Phoniatr Logop. 2008;60:298311.

47. Laukkanen A-M, Horacek J, Krupa P, Svec
JG. 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. 2010;7:5057.
48. Laukkanen AM, Horacek J, Havlk R. Case-study magnetic resonance imaging and acoustic investigation of the effects of vocal warm-up on two
voice professionals. Logoped Phoniatr Vocol. 2012;37:7582.

49. Vampola T, Laukkanen A-M, Horacek J, Svec
JG. Vocal tract changes
caused by phonation into a tube: a case study using computer tomography
and finite-element modeling. J Acoust Soc Am. 2011;129:310315.
50. Horacek J, RadolF V, Bula V, Vesely J, Laukkanen A-M. Experimental investigation of air pressure and acoustic characteristic of human voice. Part
1: measurement in vivo. Proceedings of the 18th International Conference
on Engineering Mechanics; 2012:403417.
51. Titze I. How to use the flow resistant straws. J Singing. 2002;58:429430.