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Fairbanks, Grant. Experimental Phonetics – T25

A Study of Minor
Organic Deviations in ‘Functional’ Disorders
of Articulation:
1. Rate of Movement of Oral Structures *1

Grant Fairbanks
D. C. Spriestersbach **2

For purposes of classification, administration,
and general orientation many
speech pathologists use the terms
functional 13 and organic. It is recognized
that these are labels of convenience;
that speech disorders to
which they are affixed are not all-or-none;
that so-called ‘functional’ disorders
have their organic elements;
that so-called ‘organic’ disorders have
their functional elements. But in spite
of such admirable reservations one receives
the impression that examination
and clinical practice are sometimes
carried out as if there were a
true dichotomy, and that the details
of clinical practice in particular are
commonly more appropriate to the
labels than to the disorders. Especially
does this appear to be the case with
the ‘functional’ disorders of articulation.
Minor organic deviations thought
to be adverse to speech are found in
many persons with adequate or superior
articulation. Unguided compensations
presumably have taken
place. When similar deviations are observed
in persons with articulatory
disorders it is to be feared that their
importance is minimized, and that
they are often ignored in corrective

The present investigation was designed
to examine the above observations
experimentally. Its purposes may
be stated in the form of two questions:
Are there organic differences
of any magnitude between persons
with ‘functional’ articulatory disorders,
as ordinarily classified, and persons
without disorders? If so, what
are some of the specific differences?
The general procedures may best be
explained in terms of a hypothetical

For reasons that will become clear,
suppose that a jury of speech pathologists,
employing ordinary clinical
standards, were to remove from a given
population of adults those individuals
whom they regard as having
‘organic pathologies’ of the speech or
hearing mechanisms, those with ‘foreign
dialects,’ those with ‘substandard
regional dialects,’ those whose speech
207deviations consist exclusively of ‘voicing
errors,’ 24 and those who ‘stutter.’
The remaining individuals would differ
in articulatory ability and could
be so distributed. Those at the lower
end of such a distribution would
usually be classified by the speech
pathologist as ‘functional articulatory
defectives.’ Suppose that there be
postulated two measures: (1) A single,
valid measure of articulatory ability;
(2) a single, valid measure of the
goodness of the speech-hearing mechanism.
Let both measures be applied
to the hypothetically restricted population
and the results correlated. One
would predict that the correlation
would be low but positive. Now let
the restricted population be distributed
according to the measure of
articulatory ability, let there be drawn
from each extreme of the distribution
a random sample, and let the samples
be compared on the basis of the measure
of the speech-hearing mechanism.
Following the above reasoning, one
would predict that the difference between
the two samples would be small
but significant.

It is with comparison of extreme
groups that the present investigation
has been concerned. But there are
several differences between the hypothetical
development and the actual
experimentation. First, it will be noted
that single measures of both articulatory
ability and the speech-hearing
mechanism were postulated. Neither,
however, exists. In the absence of a
satisfactory measure of articulatory
ability the experimenters employed
the screening criteria described under
Procedure, which, although defensible
for the identification of extremes,
were not useful as quantitative measures.
In the case of the speech-hearing
mechanism no over-all measure was
attempted, but a large number of specific
measurements and estimates were
made of the structure or function 3 5of
the following single components:
(1) the movement of oral structures;
(2) the lips; (3) the tongue; (4) the
teeth and hard palate; (5) hearing.
Separate reports, of which this is the
first, will be made of each portion.

In the second place, the selective
character of the college population
from which the subjects were drawn
clearly restricts interpretation and application
of findings. This population
was sampled because of availability of
subjects, and because estimates of the
speaking ability of all individuals already
had been made, and could be
used for preliminary screening as described
below. With the particular
issues involved this limitation probably
was not unduly serious.

The third major difference between
hypothetical and experimental conditions
was the formation of separate
sex groups. The expectation of systematic
differences in dimensional
measurements was the chief reason for
this. It was also considered a possibility
that in some items the ability
groups might differ in one sex but not
in the other. Such a finding, however,
would need to be interpreted with
caution since, as is explained below,
the sex groups were not perfectly
208matched with respect to articulatory


Selection of Subjects

Selection of Subjects. Sixty young
adults enrolled at the State University
of Iowa, ranging in age from 17 years,
six months to 24 years, four months,
were selected on the basis of superiority
or inferiority in articulation of
consonants, equal sex groups of 15
each being formed at both ability
levels as follows:

tableau superior | inferior | male | female

Preliminary identification of subjects
was accomplished by studying information
obtained in connection
with a beginning course in speech.
The records included examiners' ratings
of the speaking performances
made by approximately 1250 students,
largely freshmen. Ratings had been
made according to the method of
Barnes (7), in which certain attributes
of speaking are rated on a 1-to-7
scale. Among the items were Pronunciation
and Voice Control, which
afforded two bases for evaluation,
neither of which was a direct measure
of ability to articulate consonants, but
both of which, according to the practice
of examiners, included that ability.
Ratings on these items for the
first and last major speeches of the
first semester, given approximately
four months apart, were averaged
separately. The preliminary lower
limit of the superior extreme was defined
as an average rating of 5.0 on
Pronunciation and of 4.0 on Voice
. The upper limit of the inferior
extreme was established as an
average of 3.0 on Pronunciation.

Final limits were determined by
means of a direct test of ability in
consonant articulation. The test, an
inventory-type analysis of consonant
elements, employed the materials and
procedures of Fairbanks (2), in which
loaded sentences, one for each of 25
elements, are read by the subject.
Each consonant was rated on a 1-to-5
scale by two judges who served for
all subjects. Both judges were professional
speech correctionists with extensive
experience in articulatory disorders,
and with superior articulation
and normal hearing by test. During
the test the subject was seated at a
distance of approximately 10 feet
from the judges, who in turn were
separated and made their ratings independently.
The mean of the two
ratings of each consonant was used
as the ability measure for that consonant.

Persons identified by the preliminary
screening were called in at random
for the above test until the four
experimental sub-groups were complete
in number, which was accomplished
with the testing of 121 persons.
Three criteria of acceptance
were used. The first excluded from
any group persons with cerebral palsy,
cleft palate, or other obvious defect
of the speech mechanism, and persons
with claimed hearing impairment in
response to question. The intention
here, in view of the purpose of the
investigation, was to restrict the subjects
to those ordinarily regarded as
‘functional’ types. The second criterion,
in order to simplify the problem
and on grounds of no necessary connection,
excluded persons with substandard
regional dialect, foreign dialect,
persons whose only defects of
articulation were voicing errors, and
stutterers. These procedures were carried
out by the experimenters, all of
whom were experienced in speech
pathology, and involved the usual
209clinical methods of initial interview
and examination. Some of the excluded
cases had been studied previously
by the Speech Clinic and records
were available; others were not
excluded until the articulation test
had been completed. The third criterion
employed the results of the articulation
test. Since the experimenters
felt that one mark of superiority
is uniformity, the minimum requirements
for the superior group were
(1) no mean rating lower than 3.0,
and (2) at least 20 of the 25 mean
ratings higher than 3.0. The requirement
for the inferior group was a
mean raring of 1.0 (i.e., minimum
raring by both judges) on at least one
consonant. In the latter instance it
was considered, on the basis of clinical
experience, that an individual may be
regarded as having clinically defective
articulation if any one of the elements
deviates extremely, and that a justifiable
upper limit for the inferior
groups could thus be defined. In practice
only seven of the 30 inferior subjects
barely met this criterion, while
one subject presented five sounds
rated 1.0.

It will be observed that no attempt
was made to match cases for the two
sex groups at each ability level, subjects
who met the criteria being admitted
at random. Without measures
which can be used with confidence
for quantitative comparison it is difficult
to make statements regarding
equivalence. The superior male and
female groups, with a strict requirement
of uniformity and a high lower
limit, had mean ratings per consonant
of 3.6 and 4.7, respectively. Similar
figures for the two inferior groups
were 3.9, with a range of 3.5 to 4.4,
and 3.1, with a range of 3.8 to 4.4,
but are of doubtful quantitative value
considering the criteria. Another possible
index for comparison of the inferior
groups is the number of defective
sounds per subject. The mean
number of consonants rated 1.0 was
2.7 for the inferior male subjects, and
2.1 for the inferior females. In terms
of number of consonants rated lower
than 3.0 the male and female means
were 5.1 and 3.7, respectively. The
fact that all of the above values seem
to indicate slight inferiority of the
males is suggestive, but the experimenters
do not believe that a definitive

Table 1. Ascending rank order of mean
ratings of consonants, and number of subjects
rated lower than 3.0. Thirty inferior

tableau number of subjects rate | mean rating | 1.0 | lower than 2.0 | lower than 3.0 | [s] | [ʃ] | [z] | [ʒ] | [tʃ] | [dʒ] | [ʍ] | [v] | [l] | [f] | [ɵ] | [t] | [ð] | [d] | [ŋ] | [r] | [w] | [m] | [n] | [k] | [p] | [b] | [g] | [h] | [j]210

conclusion can be reached with
these methods of estimation, which
were designed to screen rather than
to measure.

In Table I the consonant elements
arc arranged in ascending rank order
of the mean ratings of the 30 inferior
subjects. It will be noted that the
usual consonants head the list. If these
means are referred to the l-to-5 scale,
with 3.0 considered as ‘average,’ it
will lie seen that only the upper six
fall below that value. The last three
columns show the frequency of ratings
lower than 3.0, and are cumulative
from left to right. Much the
same concentration may be observed.
In only one case was the rating of
[s] 3.0 or higher, while on 16 of the
25 consonants all subjects were rated
3.0 or higher. In summary, the groups
of inferior subjects, restricted by exclusion
to ‘functional’ cases, displayed
distinct inferiority in articulation of
only the following consonants: [s],
[ʃ], [z], [ʒ], [tʃ], [dʒ]. Scattered
subjects were inferior in articulation
of [ʍ], [l] and [ɵ]. For the remaining
consonants articulation was rated

Three subjective observations regarding
the subjects seem to be in order.
First, it was the general impression
of the experimenters that the articulation
of the inferior subjects was
unmistakably defective, while that of
the contrasting subjects was definitely
superior. Second, there seemed to be
no sex-linked differences in articulation
within cither of the two ability
levels. Third, the extreme groups
were not obviously different in any^
systematic way with respect to observable
superficial characteristics such
as appearance, size, and manner.


Apparatus. The technique employed
in the portion of the study reported
here involved the recording and
counting of rapid, repetitive movements
as follows: (1) Approximation
of upper and lower lips. (2) Vertical
movement of the mandible. (3) Contact
between the tongue and alveolar
ridge. (4) Protrusion of the tongue.
(5) Vertical movement of the eyebrow. 46
Recording was accomplished
by means of apparatus which counted
the total number of movements completed
during a three-second interval.
The main component was a vacuum
tube-relay unit, similar to that described
by Koepp-Baker (3), in which
a relay was tripped when a high resistance,
low amperage current (below
shock threshold) was connected across
the input terminals. The relay operated
a Stoelting counter which recorded
every make-and-break. The
three-second sampling interval was
produced automatically by an electronic
device which disconnected the
counter from the relay three seconds
after the two had been connected by
manual switch. The mean deviation of
the interval for 50 trials was 0.0055
sec. The length of the interval was
selected on the basis of preliminary
tests which showed such a period to
be suitable from the standpoint of
sustained rate of movement.

The relay unit was activated by
means of the various applicator-switches
shown in Figure 1. All but
the tongue-alveolar switch (II) were
mounted on a framework so that they
could be -adjusted individually to the
seated subjects. Part I shows top and
side views of the contact device for
tongue protrusion. The jacket, C, was
made by flattening a piece of brass
piping until it was elliptical in cross-section,
its shorter diameter measuring
approximately 7/8ʺ. A bakelite
plate, D, closed one end. An adjustable211

image scale

Figure 1. Diagrams of applicator-switches used in measuring rate of tongue protrusion
movement (I), tongue-alveolar movement (II), lip movement (III), and jaw movement

metal rod, G, with a metal contact
plate, A, on one end, projected
through the center of D and was fixed
by means of a set-screw, F. The brass
jacket, insulated thus from rod and
contact plate, was placed between the
subject's teeth, the grooves, B, receiving
the incisors. Although, for purposes
of explanation, plate A is shown
projecting beyond the jacket, during
experimentation the plate invariably
was entirely within the jacket, anterior
to the subject's incisors. Its
antero-posterior position was adjusted
212during a preliminary practice period
by moving rod G until the subject
judged the position to be most advantageous
for maximum rate of
movement. This adjustment having
been made, one wire lead from the
relay was connected to terminal E,
while the other lead was fastened to
the subject's ear by means of a modified
brass earring. Contact between
the subject's protruded tongue and
plate A. inside the jacket, completed
the circuit and tripped the relay.

Part II of Figure 1 shows a side view
of the device used for tongue-alveolar
contact. A hollow bakelite cylinder,
R. was closed at one end by a thin
bakelite disc. A, of larger diameter,
producing the hat-shaped appliance
shown. The inside of B was filled with
solder which formed the contact
point, and to this was attached a piece
of No. 32, enamel-insulated, copper
wire, C, leading to one relay terminal.
The other terminal was connected
to the subject's ear as described
above. The contact device was taped
to the alveolar ridge in the midline
immediately posterior to the upper incisors
by means of a strip of adhesive
tape in which a hole large enough to
accommodate B was cut. The area was
dried with a swab before taping. Contact
between the tongue and the solder
core of B closed the circuit.

Lip movements were indicated by
means of the simple switch shown at
III. .Made of spring bronze and
mounted at a right angle to the insulated
handle, B, the switch closed
in response to a slight smacking-like
movement when placed between the

In IV of Figure 1 is shown a side
view of the switch to indicate jaw
movement. The free end of the hinged
lever, D, was placed on the upper
edges of the lower incisors. In its basic
position lever D rested on a stop,
which was formed by bending the
lower end of C at a right angle, and
which prevented further downward
movement. Upward movement was
opposed by a light helical spring, B.
The relay circuit was closed whenever
lever D, following an upward movement
of the jaw, touched contact A.
For this measurement head position
was fixed by resting the upper teeth
upon a wooden tongue blade which
was clamped at both ends and was
adjustable vertically.

The device used for brow movement
is not shown since it resembled
closely that for jaw movement. Essentially,
it was the switch of IV,
Figure I, inverted, with lever D
maintaining light contact with A unless
raised. Downward movement beyond
the position of contact was restrained
by means of a stop similar to
C; lever D rested upon this stop in its
basic position. Spring B was not used.
A flexible wire attached to the free
end of D was taped to the right eyebrow,
and the appliance lowered until
slack was absent. A slight upward
movement of the brow was sufficient
to break the contact at A and activate
the relay. The head positioner was
employed as for jaw movement.

During the experimental procedure
the subject was seated and the various
appliances were swung into position
one at a time and adjusted. The counter
and relay were out of the range of
vision. General instructions were to repeat
the movement as rapidly as possible,
beginning on signal and continuing
until stopped. Each measurement
was preceded by a practice period.
After the subject was able to sustain
the repetition and was satisfied that
he had reached maximum rate, the
starting signal was given. As soon as
sustained movement was definitely213

Table 2. Means, standard deviations, and differences. Units: mean number of movements
per second.

tableau movement | superior | inferior | difference | lips | male female | AM | SD | jaw | tongue-alveolar | tongue protrusion | brow

* Superior — inferior

established, the counter switch, which
also started the automatic interval
timer, was closed.


Tables 2 and 3, in which the results
are presented, should be considered
together for adequate interpretation.
All values are expressed in
mean number of movements per second,
and were derived from individual
means based upon the three-second
sampling interval. The primary
purpose of the investigation being
to study rate of movement in relation
to articulatory ability, comparisons
of the superior and inferior
groups within sex and within measure
are of greatest interest. The data also
permit, however, comparisons of
males and females, and of the five different

Study of the means and standard
deviations in Table 2 shows differences
of varying magnitudes in all
three of the above types of comparison.
That some of these differences
reach significance at the 1% level was
shown by an obtained F of 22.62,
with approximately 1.62 required. 57
Table 3 gives the results of ‘factorial’
analysis, using an ability-by-sex arrangement
with each measure separately.
If the F ratios in the first
column are compared to the required
4.16 and 2.78 at the 1% and 5% levels,
respectively, it will be seen that evidence
for rejection of an hypothesis
of zero difference between the four
groups is present for lip movement
and tongue protrusion movement

In the case of lip movement, evaluation
of the remaining ratios reveals
that for articulatory ability the F of
8.35 exceeds the tabled 1% value, suggesting214

Table 3. Analysis of variance. Units: mean number of movements per second.

tableau source of variation | movement | between groups | ability | sex | interaction | within groups | lips | jaw | tongue-alveolar | tongue protrusion | brow

* df: Between Groups, 3
Ability, Sex, Interaction, 1
Within Groups, 56

F = Given Variance / Within Groups Variance
F, 3 & 55: 1%, 4.16; 5%, 2.78
1 & 55: 1%, 7.12; 5%, 4.02

the existence of a real difference.
The sex and interaction values
are too small for significance, although
the former barely fails at the
5%, level. In Table 2 the minimum
differences required for significance
between any two lip movement means
are 1.04 at the 1% level and 0.78 at
the 5%, level. For ability levels within
sex it is seen that this requirement
is met only in males, where the difference
is 1.06 in favor of the superior
group. Variance was also greater for
the superior male group, 1.82 compared
to 0.55. The ratio of the two,
F, is 3.31, significant beyond the 10%
level. This lack of homogeneity is interesting
in itself; and it does not,
furthermore, alter the interpretation
of the difference between means,
which was found to lie large enough
to withstand a more rigorous test. 68

For tongue protrusion movements,
the only other measure with significantly
large variance between groups,
the analysis of Table 3 yields a very
small F for ability, but a substantial
value for sex. Again, according to
Table 2, the difference is in favor of
the male, but with the requirement of
0.95 or 0.71, however, at the 1% or
5% levels, respectively, this rate advantage
is once more seen to be significant
only for superior males. The
F for interaction is significant at the
5% level, and it may be observed in
Table 2 that the direction of the differences
between ability groups differs
for the two sexes.

In tongue-alveolar movements the F
of 4.68 for sex is significant at the 5%
level (which might be thought of as
suggesting the presence of a between-sex
difference, ability constant), but
the variance between groups is small
and the differences between the basic
sex groups (Table 2) are less than the
required 0.63 at the 5% level.

While it was not an objective of the
study to compare the rates of movement
of various structures, the data
of Table 2 are worth comment in this
regard. The five measures have been
arranged in general descending rank
order, and vertical comparison of
215means will show that this order is
preserved within three of the four
subject groups. It will also be noted
that the range of rate, from lip to
brow movement, is substantially greater
than the differences between groups
for any given structure. Interpretation
of the difference between any
two means in a subject group may be
made with a requirement of 0.86 or
0.65 for significance at the 1% or 5%
level, respectively. If these criteria
are used the following seem to be the
outstanding points: Brow movement
is invariably slower than any other;
tongue protrusion movement is invariably
slower than lip movement (it
is also slower than jaw movement in
three groups, and slower than tongue-alveolar
movement in two groups);
jaw movement and tongue-alveolar
movement differ significantly in no


From a population of young adults
four groups of subjects were chosen
on the basis of sex and ‘functional’ articulatory
ability: 15 males and 15 females
with superior consonant articulation;
15 males and 15 females with
inferior consonant articulation. Numerous
measurements of the structure
or function of the speech-hearing
mechanisms were made. The results
of the investigation, too lengthy for
a single article, are to be presented in
a series, and will be summarized and
interpreted in the final paper. The
present report has been confined to
the data on the rates of repetitive
movements, expressed in mean number
per second, of lips, mandible,
tongue to alveolar ridge, tongue protrusion.
Rate of eyebrow movement
was also measured. Findings of this
portion of the study were as follows:

1. All differences between ability
groups were small. In lip movement a
significant difference in relation to articulatory
ability was found, but only
for the male. In this sex a difference
of 1.06 between means was obtained
in favor of the superior group.

2. Differences between sex groups
were consistently in favor of the male,
but failed of statistical significance in
most instances. The general analysis
showed significant sex variance in
tongue protrusion and tongue-alveolar
movement, but the difference between
basic sex groups, ability constant,
reached significance only in tongue
protrusion, and only at the superior

3. Some of the differences between
the various structures were found to
be large and significant. In all four
groups movements of speech structures
were uniformly found to be significantly
faster than movement of
the eyebrow. In descending order the
speech structures ranked as follows:
Lips, mandible, tongue-alveolar,
tongue protrusion. Lip movement was
found to be significantly faster than
tongue protrusion in all four groups.


1. Barnes, H. G. Speech Handbook. New
York: Prentice-Hall, 1942.

2. Fairbanks, G. Voice and Articulation
. New York: Harper, 1940.

3. Koepp-Baker, H. An electrical phono-kinesograph
and its applications to the
study of speech. Ph.D. Dissertation,
State Univ. Iowa, 1938.

4. Snedecor, G. W. Statistical Methods
(4th Ed.). Ames: Iowa State College
Press, 1946.216

1* Reprinted from the Journal of Speech and Hearing Disorders, Vol. 15, 1950, pp. 60-69.

2** Grant Fairbanks (Ph.D., Iowa, 1936) is
Professor of Speech, University of Illinois.
D. G. Spriestersbach (Ph.D., Iowa, 1948) is
Assistant Professor of Speech, State University
of Iowa.

31 In the sense of ‘non-organic.’

42 Interchange of phonetic cognates, as
[s] for [z].

53 The classification of certain functions
(such as rate of lip movement, amount of
tongue force, hearing acuity, etc) under the
‘organic’ label might be questioned. The
measurements were made because they
promised to provide data about aspects of
the mechanism which could not be readily
investigated in any other way. The experimenters
take the position that this usage
is not crucial to the major issues of the
study. The reader who disagrees is invited
to interpret the findings according to definitions
of terms that are acceptable to him.

64 Included because of measurement in
previous studies.

75 df, 19 & 280

86 Outlined by Snedecor (4, p. 83). Given
equal groups, the t- table is entered with
one-half the indicated degrees of freedom.
The difference of 1.06 was found to remain
significant beyond the 5% level.