Management of Ear-Canal Collapse
Lynne Marshall, PhD, Mary A. Gossman, MA
• Thresholds were measured at 250,
500, 1,000, 2,000, 3,000, 4,000, 6,000,
and 8,000 Hz in 20 normal adult ears and
in ten ears from adults with varying
amounts of ear-canal collapse. To alleviate the attenuation caused by ear-canal
collapse, ear-canal inserts, postauricular
pads, or circumaural cushions (Telephonics 510-020) were used with earphones
(TDH-49). The circumaural cushions provided the lowest thresholds for the listeners with ear-canal collapse. Although
thresholds with the ear-canal inserts were
comparable to those with the circumaural
cushions for many of the listeners, the
ear-canal inserts were not suitable for
listeners with more severe ear-canal collapse because the insert was displaced
when the supra-aural cushion was placed
on the pinna. Thresholds with the postauricular pinna pads were higher than with
the circumaural cushions for most individuals.
(Arch Oto/aryngo/1982;108:357-361)
hanges often take place in the
C
dermis with increasing age,t
particularly degeneration of the elastic fibers 2•3 and a decrease in collagen.'
These changes cause the tissue to lose
its elasticity and strength. As a result,
the cartilaginous portion of the ear
canal becomes more flexible and may
constrict or completely close when an
earphone is placed on the pinna.
Schow and Randolph 5 reported a 36%
incidence of ear-canal collapse in an
elderly (aged .60 to 79 years) population, and the incidence for nursinghome residents is ·even higher. 6•7
Schow and Randolph 5 estimated
Accepted for publication Oct 28, 1981.
From the Department of Counseling and Special Education, University of Nebraska at Omaha
(Dr Marshall); and Archbishop Bergan Mercy
Hospital, Omaha (Ms Gossman).
Reprint requests to Department of Counseling
and Special Education, University of Nebraska at
Omaha, Omaha, NE 68182 (Dr Marshall).
Arch Otolaryngoi-Vol 108, June 1982
that ear-canal collapse may account
for a 5-dB error in earphone threshold
norms for the elderly. · Bowever,
threshold shifts for individual listeners may be as large as 20 to 30 dB,
especially at 1,000 Hz and above.'
Several solutions have been suggested: Chaiklin and McClelland8 tried
a hand-held earphone, a stock ear
insert of the type used for hearing-aid
evaluations, the NAF circumaural
cushion with TDH-39 earphones, and
sound-field assessment on 12 adults
with no evidence of ear-canal collapse
and on 12 subjects of all ages (including children) with collapsible ear
canals. These various arrangements
were compared with TDH-39 earphones with MX-41/ AR cushions. The
hand-held earphone resulted in a leak
of energy at 2,000 Hz and below, and
the ear insert resulted in a highfrequency attenuation.
These authors concluded that circumaural cushions or sound-field
evaluation should be employed with
individuals having collapsi'ble ear
canals. However, there is no standard
for calibration of earphones with circumaural cushions. Also, threshold
evaluations in sound field often are
not practical due to the need for a
controlled acoustic environment and
special signals (narrow-band noise or
warbled tones). Additionally, there is
no standard to specify the acoustic
characteristics of these stimuli for
commercial audiometers. Therefore, it
would be advantageous to find a solution to ear-canal collapse that would
be compatible with TDH-49 earphones with MX-41/ AR cushions, for
which there are standards.
Audiologists often use acousticimmitance probe tips as ear-canal
inserts with standard earphones and
cushions. These probe tips, however,
result in an attem,J.ation of high fre-
quencies similar to that found for
stock ear-mold inserts. 9
In the present study, we used earcanal inserts and postauricular pads
with TDH-49 earphones and MX-41/
AR supra-aural cushions, and also
Telephonics 510-020 circumaural
cushions. The object was to find an
earphone arrangement that would
alleviate ear-canal collapse without
introducing unwanted acoustic effects
and that would provide minimal
intrasubject and intersubject vanability.
METHOD
Subjects
Two groups of subjects were used. The
first group consisted of ten adults under
age 35 years with normal tympanograms,
acoustic reflexes at normal sensation levels, and no evidence of ear-canal collapse.
Both ears were used for these subjects. The
second group consisted of adults with highfrequency air-bone gaps whose ear canals
appeared to collapse with pressure on the
pinna. Each subject was identified as having ear-canal collapse by one of five audiologists. Thirteen subjects identified as having ear-canal collapse, aged 21 to 86 years,
participated in the study. Nine of the subjects appeared to have monaural ear-canal
collapse; four had binaural ear-canal collapse. Thus, 17 ears were selected for the
experimental group.
Equipment
A Grason-Stadler 1704 audiometer was
used for all threshold measurements.
TDH-49 earphones were used for all airconduction conditions. They were calibrated" with MX-41/ AR cushions using a
Bruel and Kjaer sound-level meter with a
6-cc coupler (General Radio 9A). Thresholds were measured with MX-41/ AR
supra-aural cushions and Telephonics 510020 circumaural cushions. The ear-canal
inserts were cutoff plastic otoscope tips
with inside diameters of 5 or 6 mm and
lengths of 4 to 7 mm. The postauricular
pinna pads, made of rigid polystyrene plastic (Styrofoam) coated with varnish, were
Ear-Canal Collapse-Marshall & Gossman
357
Table 1.-Sensitivity Change, in Decibels'
tri
of
Frequency, Hz
occ
750
-12.9
-14.4
500
-12.5
-9.4
Riedner and Shimizu," 1976
-5.7
-9.3
Riedner," 1980
.. .
Schow et al," 1980
. ..
. ..
...
. ..
Present study
-6.0
. ..
-7.4
-10.0
Source, yr
Jerger· and Tillman." 1959
Chaiklin and McClelland,' 1971
250
-7.5
-8.5
-11.2
1,000
-11.6
-11.7
-11.7
.. .
-11.6
-13.9
1,500
-8.9
-10.3
2,000
-10.7
-6.7
3,000
-10.4
-8.3
4,000
-1.9
-5.6
6,000
-5.4
0
8,000
+1.9
-1.7
. ..
.. .
...
-8.7
. ..
-2.0
...
...
...
-6.2
...
-6.6
...
. ..
. ..
-12.0
-7.4
...
-3.5
. ..
-3.4
-1.2
-1.9
+5.0
(P ~ .05 on a t test) were seen at
the lowest and highest frequencies.
Thresholds were raised by 4 dB at 250
Hz, and 2 dB at 500 Hz. These changes
presumably were due to a leak of
energy at low frequencies caused by a
looser coupling between the ear cushion and the external ear. Sensitivity
at 8,000 Hz was enhanced by 3 dB.
Threshold differences between suGeneral Procedure.
pra-aural and circumaural cushions
Audibility thresholds were measured at
are shown in Table 1 for several
250, 500, 1,000, 2,000, 3,000, 4,000, 6,000, and
studies. Jerger and Tillman 13 used
8,000 Hz under four conditions: MX-41/ AR
PDR-10 earphones with MX-41/ AR
supra-aural cushions, MX-41/ AR cushions
and Telephonics 510-020 circumaural
with ear-canal inserts, MX-41/ AR cushcushions. Chaiklin and McClelland, 8
ions with postauricular pinna pads, and
Riedner and Shimizu, 14 and Riedner 15
Telephonics 510-020 circumaural cushions.
used TDH-39 earphones with MX-41/
Threshold measurements also were made
AR and NAF 48490-1 cushions. Schow
at 750 and 1,500 Hz for the MX-41/ AR and
et al' 6 used TDH-39 earphones with
Telephonics 510-020 cushions in order to
obtain more complete data on supra-aural · MX-41/ AR and Telephonics 510-020
and circumaural cushion differences.
circumaural cushions. As stated earliBone-conduction thresholds were meaer, we used TDH-49 earphones with
sured at 500, 1,000, 2,000, 3,000, and 4,000
MX-41/ AR and Telephonics 510-020
Hz. Manual pure-tone audiometry with a
cushions. The same general trend can
5-dB step size was used for threshold meabe seen across· all studies. For fresurements (American National Standards
from 250 to 3,000 Hz, greater
quenCies
Institute 83.2 12 standard except that 200input
to
the
earphones is required for
ms pulsed tones were used).
thresholds with circumaural cushions
Contralateral masking was not used durin order to equal thresholds obtained
ing air-conduction measurements unless
with standard supra-aural cushions.
there was a possibility of crossover of the
test signal. Cont'ralateral masking was
This result is to be expected since the
used during all bone-conduction measurevolume under the ear cushion is larger
ments unless there was a possibility of
with the circumaural cushions, and
crossover of the masker.
sound pressure is inversely related to
The order of presentation of the various
volume at frequencies less than 1,000
earphone or bone vibrator conditions was
Hz. The differences between circumrandomized. Following a rest, all ·conaural and supra-aural cushions disapditions were ·replicated once. Testing was
pear .at higher frequencies. Here the
completed in one session.
circumaural earphone allows concha
RESULTS AND COMMENT
resonance to occur, with. an increase
Normal Subjects
in sound pressure at high frequencies
somewhat offsetting the effect of the
Thresholds were unaltered by the
larger volume.
ear-canal insert; all threshold changes
lntersubj ect variability between
were less than 1 dB. For the pinna
pad, statistically significant changes
conditions was measured separately
358
Arch Otolaryngoi-Vol 108, June 1982
otl
pir
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ga]
pac
• Caused by substituting circumaural for standard supra-aural cushion. Data are from 20 normal ears.
shaped to fit behind the pinna. Boneconduction measurements were made with
a Radioear B-70-A bone vibrator for the
normal group. The bone vibrator was
changed to a Radioear B-71 bone vibrator
prior to data collection on the listeners
with .ear-canal collapse. Calibration of
both bone vibrators was accomplished with
an artificial mastoid (Bruel and Kjaer),
using values from Dirks et al."
M~
for each frequency (Hartley's test for
homogeneity of variance' 7 ) •. No differences were found between the
MX -41/ AR cushions and any of the
other conditions (MX-41/ AR cushions
with insert, MX-41/ AR cushion with
pinna pad, and circumaural cushions)
at any frequency.
Correlations (Pearson r) between
thresholds on the two replications and
the SEs of measurement were computed and are available from the
authors. The lowest correlations were
seen at lower (< 2,000 Hz) frequencies, probably due to the restricted
range of thresholds in our young listeners at these frequencies. No earphone condition appeared to be clearly
superior to any of the other conditions
for listeners without ear-canal collapse.
Subjects With Ear-Canal Collapse
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Some of the subjects identified as
having ear-canal collapse by the audi:
ologists did not show measurable earcanal collapse in our study. That is, we
either found only a negligible air-bone
gap or were unable to demonstrate
much improvement in air-conduction
thresholds using any of the methods
to correct for ear-canal collapse. Thus,
we were required to set a more definitive criterion for ear-canal collapse
group selection. The criterion suggested by Chaiklin and McClelland8
and employed by Schow and Randolph,5 Schow and Goldbaum/ and
Schow et a1 16 was a 15-dB lowering of
threshold with circumaural cushions
at any frequency. In order to ensure
that we would not get false-positives
using this criterion, we examined the
data for the 20 normal ears. We
treated each of the two replications as
a separate trial, so that we had 40
ciaii
Hz/
mig;
by 1
mea
fals;
freq
two!
Ear-Canal Collapse-Marshall & Gossman
Arch
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trials in all. We counted the number
of times a 15-dB lower threshold
occurred between air conduction with
MX -41/ AR cushions and each of the
other conditions (insert, postauricular
pinna pad, circumaural cushions, and
bone conduction).
Out of 40 measurements, air-bone
gap, insert, and postauricular pinna
pad each resulted in two false-positives, and the circumaural cushion
resulted in· five false-positives. The
false-positives for the air-bone gap
criterion were not surprising since an
air-bone gap of this magnitude can be
due to test variability. 18•19 Test variability could also account for the
false-positives found for the insert
and postauricular pinna pad. However, we did not expect the higher falsepositive rate for circumaural cushions
because Schow and Randolph 5 reported no false-positives in 40 normal
ears. Their measurements, however,
were at 500, 1,000, 2,000, and 4,000 Hz,
while we used additional frequencies.
One of the false-positives for the circumaural cushion was at 3,000 Hz,
while the remaining four were at 6,000
and 8,000 Hz. The false-positives for
the inserts were at 4,000 and 6,000 Hz,
and the false-positives for the postauricular pinna pad were at 6,000 and
8,000 Hz. Because different earphone
placements result in variations of the
sound pressure in the ear canal, especially for frequencies above 3,000
Hz, 20"22 high-frequency thresholds
might be expected to differ more often
by 15 dB or greater due to test-retest
measurement error. We found no
false-positives in normal. ears at any
frequency if we used the mean across
two replications for each ear.
Our final criterion was a 15-dB lower threshold at any one frequency or a
10-dB lower threshold at any two
adjacent frequencies for insert, postauricular pinna pad, or circumaural
cushion in comparison with the standard MX-41/ AR supra-aural cushion.
The thresholds were the mean across
two replications. This criterion gave
no false-positives for the normal ·
group. Since one of our listeners with
suspected ear-canal collapse had a
mixed hearing loss, we did not include
air-bone gap in the criterion.
When our final criterion was
Arch Otolaryngoi-Vol 108, June 1982
applied to the 17 ears with suspected
ear-canal collapse, seven were eliminated, a sizable number to eliminate
when they had been identified by
audiologists as having ear-canal collapse. As stated earlier, all subjects
appeared byvisual inspection to have
at least some degree of ear-canal collapse. However, the amount of hearing loss caused by the ear-canal collapse apparently was so small that it
was obscured by test variabiljty. Had
we used a smaller step size (eg, 2 dB)
and a test procedure that results in
less variability (eg, adaptive twointerval forced choice), we might have
been able to document the small
effects of ear-canal collapse in these
individuals. For clinical purposes,
however, such small effects are relatively unimportant. In some cases
the audiologist's initial test results
showed larger air-bone gaps than we
found on either the initial test or the
replication, which brings up the possibility that earphone placement may
have played a role in air-bone gap size.
In collapsing canals, not only does
direct pressure on the pinna appear to
push the posterior wall forward, but if
the pinna is pushed forward, the closure of the meatus is even greater.
Thus, careful placement of the earphones is important. Of equal importance is that a patient not readjust
the earphones, which .may occur unbeknownst to the audiologist.
Our final group of ten ears, selected
by the above-stated criterion, was
divided into two groups for purposes
of data analysis. These two groups
could be differentiated by two factors:
(1) the amount of loss caused by the
ear-canal collapse as well as the frequencies at which the air-bone gap
occurred, and (2) the way in which the
insert fit into the ear canal once an
earphone was placed on the pinna.
The first group consisted of eight ears
with attenuation caused by ear-canal
collapse no greater than 20 dB at one
to four frequencies at 1,000 Hz and
above, with 3,000 to 6,000 Hz being
affected most often. Although in some
of these subjects the insert became
displaced slightly outward when pressure was placed on the pinna, in no
case did the insert become completely
dislodged. The data from these eight
~o~o~-L~~~~1~.o~o~o--~-L~~~
Frequency, Hz
Fig 1.-Pure-tone thresholds for eight ears
with ear-canal collapse under various earphone or bone-conduction conditions. Circles indicate MX-41 I AR cushion; squares,
insert; triangles, pinna pad; diamonds, circumaural cushion; and asterisks, bone cond_uction. HL indicates hearing level.
i,
o.____
'-o--
L>,,_
............c:..~~~~--6 ..........\,
--~--
..J
I
OJ
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-c
0
.<::
~
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·~
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____ o_\',,
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0,
··- ••L>..
······o-- ----D-- ----a,
o. __
···o-.... -o ....• -o •••. .-~
Ins
Pin
Circ
Bone
Fig 2.-Pure-tone thresholds for eight ears
with ear-canal collapse under various earphon.e or bone-conduction conditions at frequencies with significant differences across
co,nditions. Circles indicate 2,000 Hz;
squares, 3,000 Hz; triangles, 4,000 Hz; and
diamonds, 6,000 Hz. To increase visual
clarity, symbols for each frequency have
been connected. MX-41 indicates MX-41 1
AR cushion; Ins, insert; Pin, postauricular
pinna pad; Circ, circumaural cushions; and
Bone, bone conduction. HL indicates hearing level.
ears are presented as the group data
in the following analyses. One of these
eight ears had a mixed hearing loss.
The second group consisted of two
ears with more severe ear-canal collapse, and these data are presented
separately. The attenuation caused by
ear-canal collapse for these listeners
was greater than 20 dB for some frequencies, and the frequencies affected
were from 250 or 500 Hz up through
Ear-Canal Collapse-Marshall & Gossman
359
I
Table 2.-Severe Ear-Canal Collapse•
Frequency, Hz
Test Condition
Subject 1, 62 yr
MX-41/AR
250
500
1,000
2,000
3,000
4,000
6,000
a,ooo
42.5
25.0
27.5
90.0
95.0
97.5
95.0
92.0
40.0
22.5
30.0
90.0
97.5
95.0
90.0
90.0
Pinna pad
15.0
10.0
7.5
67.5
80.0
75.0
77.5
75.0
Circumaural
15.0
2.5
5.0
60.0
72.5
70.0
65.0
67.5
Bone
.. .
2.5
20.0
62.5
>65.0
62.5
. ·.·
...
Insert
Subject 2, 61 yr
MX-41/AR
15.0
12.5
20.0
75.0
80.0
82.5
77.5
90.0
Insert
10-15
10-10
15-20
55-70
60-75
60-75
55-70
65-85
Pinna pad
20.0
25.0
15.0
60.0
55.0
55.0
67.5
72.5
Circumaural
15.0
5.0
15.0
62.5
65.0
57.5
60.0
70.0
Bone
.
..
2.5
12.5
5:2.5
57.5
57.5
...
. ..
*Thresholds for each ear represent the mean across two replications except for subject 2 in the insert condition. Thresholds for each replication are shown
separaiely; for one replication the insert was in place, while for the other replication the insert was dislodged.
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8,000 Hz. Another characteristic of
these ears, which was the reason they
were dealt with separately in the data
analysis, was that the ear-canai insert
became dislodged when the earphone
was worn to the extent that the insert
was completely ineffective in preventing the ear-canal collapse.
Results for the eight ears in the
ear-canal collapse group are shown in
Fig 1. The thresholds for the pinna
pad and circumaural cushions use the
correction values established with the
normal group to equate thresholds for
these earphone arrangements to the
standard earphones.
Differences
across condition$ were not significant
(analysis of variance) for 250, 500;
1,000, and 8,000 Hz. The differences
across conditions were significant
(P :::::; .01) for 2,000 to 6,000 Hz. These
frequencies are graphed separately in
Fig 2 in a different format.
To determine which test condition
best alleviated ear-canal collapse, we
first compared the threshold for the
MX-41/ AR cushion with the ~ar-canal
insert, postauricular pinna pad, and
circumaural cushion. At 2,000, 4,000,
and 6,000 Hz, only the circumaural
cushion differed significantly (Bonferron! t test, P :::::; .05) . from the
MX-41/ AR cushion. Thus, the circumaural cushion appeared superior to
the other conditions. While at 3,000
Hz none of the earphone conditions
differed significantly from the MX41/ AR condition, all three earphone
conditions did result in lower thresholds than the MX-41/ AR condition.
Another comparison determined
360
Arch Otolaryngoi-Vol 108, June 1982
which earphone condition resulted in
closure of the air-bone gaps (significant at 2,000, 3,000, and 4,000 Hz)
between MX-41/ AR cushions and
bone conduction. Although not entirely valid because one ear had a mixed
hel).ring loss, the air~bone gap (circumaural cushion and bone vibrator)
for this listener was relatively constant (10 to 12.5 dB for the mean
across two replications) at 2,000,
3,000, and 4,000 Hz. Results of this
comparison at 2,000 Hz showed no
significant differences between bone
conduction and insert,. pinna pad, or
circumaural cushion. Thus, all . earphone conditions successfully closed
the air-bone gap at this frequency. At
3,000 Hz these three earphone
conditions all differed significantly
from the bone-vibrator condition.
That is, none of the three earphone
conditions successfully closed the airbone gap at 3,000 Hz. At 4,000 Hz the
insert and pinna pad thresholds, but
not the circumaural cushion thresholds, were significantly different from
bone-vibrator. thresholds. Therefore,
only the circumaural cushion resulted
in closure of the air-bone gap at 4,000
Hz.
A final comparison was made
among insert, pinna pad, and circumaural cushion thresholds at the same
four frequencies. No differences were
found at 2,000, 3,000, and 4,000 Hz. At
6,090 Hz, circumaural cushion thresholds were significantly lower than the
inse~t and pinna' thresholds.
The correlations (Pearson r) between thresholds on the two replica-
tions and the SEs of measurement for
the eight ears with ear-canal collapse
were computed. As with the normal
group, no condition appeared to be
clearly superior. Also, there were no
significant differences in variability
(homogeneity of variance) for the various test conditions at each frequency.
Data for the two listeners (with
sensorineural hearing loss) who had
the most severe ear~canal collapse,
and whose data were excluded from
the group analysis, are shown individually in Table 2. All th;resholds repref;ent the mean across two replications
with one exception. For subject 2, the
ear-canal insert was in place during
the iriitial testing. For the replication,
we were unable to position the insert
so that it remained in place with
pressure ori the pinna. The two
thresholds. shown for subject 2 in the
insert condition were for the first test,
with the insert in place, and for the
replication, with the insert displaced.
In conclusion, the Circumaural
cushions best alleviated the effects
of ear-ca11al collapse .because they
resulted in the lowest thresholds for
most listeners, in . agreement with
Chaiklin and McClelland: 8 While the
major disadvantage of these cushions
is that the~e is no standard at present
for their calibration, the earphones
can be calibrated in a 6-cc coupler
with supra-aural cushions. Correction
values for circumaural cushions
(Table 1) can then be applied. Calibration also can be accomplished reliably
using a flat-plate coupler/2•23 although
such a coupler is not readily available
Ear-Canal Collapse-Marshall & Gossman
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in most clinical settings. Another disadvantage is that the circumaural
cushions do not produce levels as high
as the MX-41/ AR cushions, which
limits the highest measurable hearing
loss using commercial audiometers.
We also should point out that our
results apply only to adult listeners
and not to young children or infants
with tiny, flaccid ear canals. The coupling effects of standard circumaural
cushions to small heads has not yet
been established, so our· correction
factors, as well as those of others,
apply only to adults.
Results with the ear-canal inserts
were unsatisfactory. We succeeded in
our goal of finding an insert that
did not introduce unwanted .acoustic
effects in normal ears, unlike the
stock ear mold· used by Chaiklin and
McClelland 8 or the impedance probe
used by Bryde and Feldman. 9 For five
of the eight ears with milder earcanal collapse, thresholds with the
insert were comparable to those with
the circumaural cushions. However,
with increasing severity of ear-canal
collapse, some slippage of the insert
occurred when the supra-aural cush~
ion was placed on the pinna, which
explains why the insert was not comparable to the circumaural cushions
for the group data. For the ears having the greatest amounts of ear-canal
collapse, the inserts became completely displaced. Thus, ear-canal inserts
such as ours can be used only on ears
with milder degrees of ear-canal collapse. The suitability of the insert for
a particular ear is easy to discern
visually by pressing on the pinna
after the insert is in place to determine whether slippage of the insert
occurs.
Thresholds with the postauricular
pad were higher than with circumaural cushions for most of the ears with
ear-canal collapse. The reason for this
is not entirely clear although we suspect that the pinna and posterior wall
may be pushed forward when the pinna pad is placed snugly behind the
ear. Additionally, the earphone is not
coupled as closely to the head with the
pinna pad in place, and the leakage of
energy at low frequencies for individual listeners with ear-canal collapse
can be considerable. Subject 2, whose
thresholds are shown in Table 2, illustrates this problem. The pinna pad
worked rather well for this listener
at most frequencies. However, the
threshold at 500 Hz was much higher
with the pinna pad than for any of the
other conditions. Similar problems
would be expected with a hand-held
earphone, and the coupling of the
cushion to the pinna would be more
variable, especially with the patient
holding the earphone ..
The frequencies most affected by
ear-canal collapse were above 1,000 or
2,000 Hz for listeners with mild ear-
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annual convention of the American Speech and
Hearing Association, Chicago, November 1977.
7. Schow RL, Goldbaum DE: Collapsed ear
canals in the elderly nursing home population.
J Speech Hear Disord 1980;45:259-267.
8. Chaiklin JB, McClelland ME: Audiometric
management of collapsible ear canals. Arch Otolaryngol1971;93:397-407.
9. Bryde ~L, Feldman AS: An approach to the
management of the collapsing ear canal. ASHA
1980;22:734.
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Anw·ican National Standw·ds Specifications fen·
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14. Riedner E, Shimizu H: Collapsing ears and
acoustic reflex measurement with circumaural
ear cushions. A1·ch Otolarynyol 1976;102:358-362.
15. Riedner ED: Collapsing ears and the use of
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Collapsible ear canal prevalence in an elderly
clinical population. ASHA 1980;22:734.
17. Wike EL: Data Analysis. Chicago, Aldine-
canal collapse. Only for more severe
ear-canal collapse did the effect
extend down to lower frequencies. Our
results are in agreement with those of
Chandler, 24 who systematically varied
the effect of lumen size in an ear mold
and found thresholds reduced by partial occlusion, primarily at high frequencies. When the occlusion was
nearly complete, lower frequencies
also were affected. Schow et al/ 6 however, found shifts due to ear-canal
collapse most often at 500 and 4,000
Hz and least often at 2,000 Hz. The
reason for this discrepancy is riot
apparent. Our results are in agreement with those of Schow et aP 6 in
that most threshold shifts due to earcanal collapse are 15 dB or less,
although shifts as large as 30 dB also
were observed. Thus, management of
ear-canal collapse is an important
clinical consideration. The results of
this study as well as those by Chaiklin
and McClelland8 indicate that the use
of circumaural cushions provides the
most practical solution to ear-canal
collapse.
This work was supported in part by the
Nebraska Center on Aging, Omaha.
Richard Lippman, PhD, made suggestions
throughout the project and critiqued the maimscript; Walt Jesteadt, PhD, assisted with the
data analysis and plots; Marjorie Leek, PhD, and
John Brandt, PhD, made editorial comments; and
Melanie Pruitt, MA, Roger McGargill, PhD, and
Carl Thompson, PhD, helped locate individuals
with earccanal collapse.
References
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ian
Arch Otolaryngoi-Vol 108, June 1982
Ear-Canal Collapse-Marshall & Gossman
361