Hope Lorenz
Introduction
 Three Physiological Systems Required for Voice
Production
 Respiratory
 Phonatory
 Resonation
 Voice Evaluation Includes Measures of…
 Vital Capacity
 Maximum Phonation Time
Previous Research
 Normative Values
 Vital Capacity


Males – 4180 to 4800cc
Females – 3010 to 3500 cc
 Maximum Phonation Time


Males – 24.6 to 31.6 seconds
Females – 20.9 to 24.6 seconds
 Ptacek, et al. (1966), Awan (2001), Rau and Beckett (1984), and
Shanks and Mast (1977
Previous Research Continued…
 Factors Which Influence Vital Capacity and Maximum
Phonation Time
 The best method for eliciting maximum phonation time
is the combination of verbal instructions with a full
model of the task (Soman, 1997).
 Measures of vital capacity and maximum phonation
time do not fall within normal ranges for individuals
who smoke (Awan & Alphonso, 2007)
 Increased age is associated with decreased performance
in vital capacity and maximum phonation time (Awan,
2006)
 Height most strongly predicts measures of vital capacity
(Parma et al., 1996)
Previous Research Continued…
 Impact of Vocal Training
 Singers have slightly higher measures of vital capacity
than wind instrumentalists and normal speakers
(Schorr-Lesnick, Teirstein, Brown, & Miller, 1985)
 A retrospective study compared vital capacity and
maximum phonation time of trained singers with
normative data and found no significant difference
between the two (Carroll et al., 1996)
Purpose
 Singers are trained to effectively use respiration for
phonation
 Suggests singers may be able to sustain phonation for
longer than normal speakers
 Limitations of previous studies



Retrospective
Impact of smoking
Impact of height
Research Questions
 Is there a difference in vital capacity in trained singers
versus normal speakers?
 Is there a difference in maximum phonation time in
trained singers versus normal speakers?
Participants
Trained Singers
Normal Speakers
 18-23 years old
 10 vocal majors
 At least 1 year formal vocal
 19 to 22 years old
 6 CDS majors, 2 elementary





training at collegiate level
Exercised average of 2.4 times
per week
2 Freshman, 2 Sophomores, 3
Juniors, 3 Seniors
No history of smoking
In good health
Average Height = 64.40
inches






education majors, 1 English
major, 1 marketing major
No previous vocal training
Exercised average of 3.4 times
per week
6 Seniors, 4 Sophomores
No history of smoking
In good health
Average Height = 64.40
inches
Measurements
 Vital Capacity
 Measured with a Spiropet dry spirometer
 Standing with good posture, blow air into handheld
device
 Repeatable measures within 10%
 Maximum Phonation Time
 Measured using the Visipitch IV
 Standing with good posture, continue to phonate /a/ as
long as possible
 Repeatable measures within 10%
Correlation Between Maximum
Phonation Time and Vital Capacity
5000
4000
Vital
Capacity
(in cc)
3000
2000
1000
0
0
5
10
15
20
25
Maximum Phonation Time (in seconds)
The correlation between maximum phonation time and vital
capacity was r = .24; p = .29; indicating the two measures were not
significantly correlated.
30
Maximum Phonation Results
 No significant
difference in
maximum
phonation time
between groups
 Both groups
lower than past
norms
 Maximum Phonation Time Norms
 Females – 20.9 to 24.6 seconds
 Ptacek, et al. (1966), Awan (2001), Rau and Beckett
(1984), and Shanks and Mast (1977)
Vital Capacity Results
 Vital capacity
significantly
higher in
normal
speakers; p = .02
 Trained singers
lower than past
norms
 Normal
Speakers within
past norms
 Normative Values
 Vital Capacity

4000
3500
3000
2500
Singers
2000
Control
1500
NormLow
NormHigh
1000
500
0
Vital Capacity
Females – 3010 to 3500cc
 Ptacek, et al. (1966), Awan (2001), Rau and Beckett (1984), and Shanks and Mast (1977)
Discussion of Unexpected Results
 Why was vital capacity significantly lower for trained
singers than the control group?
 Why was maximum phonation time lower for singers
than controls (although not significantly) and why
were both groups lower than past norms?
 What factors may have influenced these results?
Influence of Major
Vital Capacity
Maximum Phonation
Time
4000
3500
3000
2500
2000
1500
1000
500
0
20
15
10
5
0
CDS
Majors
Other
Normals
Vocal
Majors
CDS
Majors
Other
Normals
Communication Disorders and Sciences Majors:
Understanding of task possibly skewed results
Vocal
Majors
Influence of Exercise Each Week
Maximum Phonation
Time
Vital Capacity
4000
3500
3000
2500
2000
1500
1000
500
0
25
20
15
10
5
0
0
1 to 2
3 to 4
0
5+
1 to 2
3 to 4
Times/Week
Trained Singers
Normal Speakers
0
3
0
1-2
1
3
3-4
4
4
5+
2
3
5+
Influence of Years of Vocal Training
Vital Capacity
Maximum Phonation
Time
3000
20
18
16
14
12
10
8
6
4
2
0
2900
2800
2700
2600
2500
2400
2300
2200
One
Two
Three
Four
One
Two
Three
Four
Discussion
 Clinical Implications
 Large range of normal
 Possible contributing factors:



Profession/Education
Years of vocal training
Exercise
 Future Research
 Factors which influence measures
 Amount of vocal training