Differences in formant frequencies and fundamental frequencies (F0) are important cues for segregating and identifying two simultaneous vowels. This study assessed age- and hearing-loss-related changes in the use of these cues for recognition of one or both vowels in a pair and determined differences related to vowel identity and specific vowel pairings. Younger adults with normal hearing, older adults with normal hearing, and older adults with hearing loss listened to different-vowel and identical-vowel pairs that varied in F0 differences. Identification of both vowels as a function of F0 difference revealed that increased age affects the use of F0 and formant difference cues for different-vowel pairs. Hearing loss further reduced the use of these cues, which was not attributable to lower vowel sensation levels. High scores for one vowel in the pair and no effect of F0 differences suggested that F0 cues are important only for identifying both vowels. In contrast to mean scores, widely varying differences in effects of F0 cues, age, and hearing loss were observed for particular vowels and vowel pairings. These variations in identification of vowel pairs were not explained by acoustical models based on the location and level of formants within the two vowels.

1.
ANSI
(
2010
). ANSI S3.6-2010,
American National Standard Specification for Audiometers
(
American National Standards Institute, Inc.
,
New York
).
2.
Arehart
,
K. H.
(
1998
). “
Effects of high-frequency amplification of double-vowel identification in listeners with hearing loss
,”
J. Acoust. Soc. Am.
104
,
1733
1736
.
3.
Arehart
,
K. H.
,
King
,
C. A.
, and
McLean-Mudgett
,
K. S.
(
1997
). “
Role of fundamental frequency differences in the perceptual separation of competing vowel sounds by listeners with normal hearing and listeners with hearing loss
,”
J. Speech Lang. Hear. Res.
40
,
1434
1444
.
4.
Arehart
,
K. H.
,
Rossi-Katz
,
J.
, and
Swensson-Prutsman
,
J.
(
2005
). “
Double-vowel perception in listeners with cochlear hearing loss: Differences in fundamental frequency, ear of presentation, and relative amplitude
,”
J. Speech Lang. Hear. Res.
48
,
236
252
.
5.
Arehart
,
K. H.
,
Souza
,
P. E.
,
Muralimanohar
,
R. K.
, and
Miller
,
C. W.
(
2011
). “
Effects of age on concurrent vowel perception in acoustic and simulated electroacoustic hearing
,”
J. Speech Lang. Hear. Res.
54
,
190
201
.
6.
Assmann
,
P. F.
, and
Paschall
,
D. D.
(
1998
). “
Pitches of concurrent vowels
,”
J. Acoust. Soc. Am.
103
,
1150
1160
.
7.
Assmann
,
P. F.
, and
Summerfield
,
Q.
(
1990
). “
Modeling the perception of concurrent vowels: Vowels with different fundamental frequencies
,”
J. Acoust. Soc. Am.
88
,
680
697
.
8.
Assmann
,
P. F.
, and
Summerfield
,
Q.
(
1994
). “
The contribution of waveform interactions to the perception of concurrent vowels
,”
J. Acoust. Soc. Am.
95
,
471
484
.
9.
Backoff
,
P. M.
, and
Caspary
,
D. M.
(
1994
). “
Age-related changes in auditory brainstem responses in Fischer 344 rats: Effects of rate and intensity
,”
Hear. Res.
73
,
163
172
.
10.
Bidelman
,
G. M.
,
Villafuerte
,
J. W.
,
Moreno
,
S.
, and
Alain
,
C.
(
2014
). “
Age-related changes in the subcortical-cortical encoding and categorical perception of speech
,”
Neurobiol. Aging
35
,
2526
2540
.
11.
Bregman
,
A. S.
(
1990
).
Auditory Scene Analysis: The Perceptual Organization of Sound
(
MIT Press
,
Cambridge, MA
), pp.
1
792
.
12.
Brokx
,
J. P. L.
, and
Nooteboom
,
S. G.
(
1982
). “
Intonation and the perceptual separation of simultaneous voices
,”
J. Phon.
10
,
23
36
.
13.
Caspary
,
D. M.
,
Milbrandt
,
J. C.
, and
Helfert
,
R. H.
(
1995
). “
Central auditory aging: GABA changes in the inferior colliculus
,”
Exp. Gerentol.
30
,
349
360
.
14.
Cherry
,
E. C.
(
1953
). “
Some experiments on the recognition of speech, with one and witih two ears
,”
J. Acoust. Soc. Am.
25
,
975
979
.
15.
Chintanpalli
,
A.
,
Ahlstrom
,
J. B.
, and
Dubno
,
J. R.
(
2014
). “
Computational model predictions of cues for concurrent vowel identification
,”
J. Assoc. Res. Otolaryngol.
15
,
823
837
.
16.
Chintanpalli
,
A.
, and
Heinz
,
M. G.
(
2013
). “
The use of confusion patterns to evaluate the neural basis for concurrent vowel identification
,”
J. Acoust. Soc. Am.
134
,
2988
3000
.
17.
Clinard
,
C. G.
, and
Cotter
,
C. M.
(
2015
). “
Neural representation of dynamic frequency is degraded in older adults
,”
Hear. Res.
323
,
91
98
.
18.
Clinard
,
C. G.
,
Tremblay
,
K. L.
, and
Krishnan
,
A. R.
(
2010
). “
Aging alters the perception and physiological representation of frequency: Evidence from human frequency-following response recordings
,”
Hear. Res.
264
,
48
55
.
19.
Culling
,
J. F.
, and
Darwin
,
C. J.
(
1993
). “
Perceptual separation of simultaneous vowels: Within and across-formant grouping by F0
,”
J. Acoust. Soc. Am.
93
,
3454
3467
.
20.
Culling
,
J. F.
, and
Darwin
,
C. J.
(
1994
). “
Perceptual and computational separation of simultaneous vowels: Cues arising from low-frequency beating
,”
J. Acoust. Soc. Am.
95
,
1559
1569
.
21.
de Cheveigné
,
A.
(
1997
). “
Concurrent vowel identification III: A neural model of harmonic interference cancellation
,”
J. Acoust. Soc. Am.
101
,
2857
2865
.
22.
de Cheveigné
,
A.
(
1999
). “
Waveform interactions and the segregation of concurrent vowels
,”
J. Acoust. Soc. Am.
106
,
2959
2972
.
23.
de Cheveigné
,
A.
,
Kawahara
,
H.
,
Tsuzaki
,
M.
, and
Aikawa
,
K.
(
1997
). “
Concurrent vowel identification. I: Effects of relative amplitude and F0 difference
,”
J. Acoust. Soc. Am.
101
,
2839
2847
.
24.
Fogerty
,
D.
,
Kewley-Port
,
D.
, and
Humes
,
L. E.
(
2012
). “
Asynchronous vowel-pair identification across the adult lifespan for monaural and dichotic presentations
,”
J. Speech Lang. Hear. Res.
55
,
487
499
.
25.
Hedrick
,
M. S.
, and
Madix
,
S. G.
(
2009
). “
Effect of vowel identity and onset asynchrony on concurrent vowel identification
,”
J. Speech Lang. Hear. Res.
52
,
696
705
.
26.
Heinz
,
M. G.
, and
Young
,
E. D.
(
2004
). “
Response growth with sound level in auditory-nerve fibers after noise-induced hearing loss
,”
J. Neurophysiol.
91
,
784
795
.
27.
Helfer
,
K. S.
, and
Freyman
,
R. L.
(
2008
). “
Aging and speech-on-speech masking
,”
Ear Hear.
29
,
87
98
.
28.
Hellstrom
,
L. I.
, and
Schmiedt
,
R. A.
(
1990
). “
Compound action potential input/output functions in young and quiet-raised gerbils
,”
Hear. Res.
50
,
163
174
.
29.
Klatt
,
D. H.
(
1980
). “
Software for a cascade/parallel formant synthesizer
,”
J. Acoust. Soc. Am.
67
,
971
995
.
30.
Larsen
,
E.
,
Cedolin
,
L.
, and
Delgutte
,
B.
(
2008
). “
Pitch representations in the auditory nerve: Two concurrent complex tones
,”
J. Neurophysiol.
100
,
1301
1319
.
31.
Lee
,
J. H.
, and
Humes
,
L. E.
(
2012
). “
Effect of fundamental-frequency and sentence-onset differences on speech-identification performance of young and older adults in a competing-talker background
,”
J. Acoust. Soc. Am.
132
,
1700
1717
.
32.
Lentz
,
J. J.
, and
Marsh
,
S. L.
(
2006
). “
The effect of hearing loss on identification of asynchronous double vowels
,”
J. Speech Lang. Hear. Res.
49
,
1354
1367
.
33.
Liberman
,
M. C.
, and
Dodds
,
L. W.
(
1984a
). “
Single-neuron labeling and chronic cochlear pathology. III. Stereocilia damage and alterations of threshold tuning curves
,”
Hear. Res.
16
,
55
74
.
34.
Liberman
,
M. C.
, and
Dodds
,
L. W.
(
1984b
). “
Single-neuron labeling and chronic cochlear pathology. II. Stereocilia damage and alterations of spontaneous discharge rates
,”
Hear. Res.
16
,
43
53
.
35.
Makary
,
C. A.
,
Shin
,
J.
,
Kujawa
,
S. G.
,
Liberman
,
M. C.
, and
Merchant
,
S. N.
(
2011
). “
Age-related primary cochlear neuronal degeneration in human temporal bones
,”
J. Assoc. Res. Otolaryngol.
12
,
711
717
.
36.
McKeown
,
J. D.
(
1992
). “
Perception of concurrent vowels: The effect of varying their relative level
,”
Speech Commun.
11
,
1
13
.
37.
McKeown
,
J. D.
, and
Patterson
,
R. D.
(
1995
). “
The time course of auditory segregation: Concurrent vowels that vary in duration
,”
J. Acoust. Soc. Am.
98
,
1866
1877
.
38.
Meddis
,
R.
, and
Hewitt
,
M. J.
(
1992
). “
Modeling the identification of concurrent vowels with different fundamental frequencies
,”
J. Acoust. Soc. Am.
91
,
233
245
.
39.
Micheyl
,
C.
, and
Oxenham
,
A. J.
(
2010
). “
Pitch, harmonicity and concurrent sound segregation: Psychoacoustical and neurophysiological findings
,”
Hear. Res.
266
,
36
51
.
40.
Miller
,
R. L.
,
Schilling
,
J. R.
,
Franck
,
K. R.
, and
Young
,
E. D.
(
1997
). “
Effects of acoustic trauma on the representation of the vowel /
ɛ
/ in cat auditory nerve fibers
,”
J. Acoust. Soc. Am.
101
,
3602
3616
.
41.
Raza
,
A.
,
Milbrandt
,
J. C.
,
Arneric
,
S. P.
, and
Caspary
,
D. M.
(
1994
). “
Age-related changes in brainstem auditory neurotransmitters: Measure of GABA and acetylcholine function
,”
Hear. Res.
77
,
221
230
.
42.
Ruggero
,
M. A.
,
Rich
,
N. C.
,
Recio
,
A.
,
Narayan
,
S. S.
, and
Robles
,
L.
(
1997
). “
Basilar-membrane responses to tones at the base of the chinchilla cochlea
,”
J. Acoust. Soc. Am.
101
,
2151
2163
.
44.
Schmiedt
,
R. A.
,
Lang
,
H.
,
Okamura
,
H. O.
, and
Schulte
,
B. A.
(
2002
). “
Effects of furosemide chronically applied to the round window: A model of metabolic presbyacusis
,”
J. Neurosci.
22
,
9643
9650
.
45.
Schmiedt
,
R. A.
,
Mills
,
J. H.
, and
Boettcher
,
F. A.
(
1996
). “
Age-related loss of activity of auditory-nerve fibers
,”
J. Neurophysiol.
76
,
2799
2803
.
46.
Snyder
,
J. S.
, and
Alain
,
C.
(
2005
). “
Age-related changes in neural activity associated with concurrent vowel identification
,”
Cognit. Brain Res.
24
,
492
499
.
47.
Studebaker
,
G. A.
(
1985
). “
A ‘rationalized’ arcsine transform
,”
J. Speech Hear. Res.
28
,
455
462
.
48.
Summers
,
V.
, and
Leek
,
M. R.
(
1998
). “
F0 processing and the separation of competing speech signals by listeners with normal hearing and with hearing loss
,”
J. Speech Lang. Hear. Res.
41
,
1294
1306
.
49.
Vongpaisal
,
T.
, and
Pichora-Fuller
,
M. K.
(
2007
). “
Effect of age on F0 difference limen and concurrent vowel identification
,”
J. Speech Lang. Hear. Res.
50
,
1139
1156
.
50.
Zwicker
,
U. T.
(
1984
). “
Auditory recognition of diotic and dichotic vowel pairs
,”
Speech Commun.
3
,
265
277
.
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