In cochlear implants, or vocoder simulations of cochlear implants, the transmission of envelope cues at high rates (related to voice fundamental frequency, f0) may be limited by the widths of the filters used to form the channels and/or by the cutoff frequency, flp, of the low-pass filters used for envelope extraction. The effect of varying flp in tone and noise vocoders was investigated for channel numbers, N, from 6 to 18. As N increased, the widths of the channels decreased. The value of flp was 45Hz (envelope or “E” filter), or 180Hz (pitch or “P” filter). The following combinations of cutoff frequencies were used for channels below and above 1500Hz, respectively: EE, PE, EP, and PP. Results from a competing-talker task showed that the tone vocoder led to better intelligibility than the noise vocoder. The PP condition led to the best intelligibility and the EE condition to the worst. For N=6, intelligibility was better for condition PE than for condition EP. For N=18, the reverse was true. The results indicate that the channel bandwidths can compromise the transmission of f0-related envelope information, and suggest that vocoder simulations of cochlear-implant processing have limitations.

1.
ANSI
. (
1997
).
ANSI S3.5-1997, Methods for the Calculation of the Speech Intelligibility Index
(
American National Standards Institute
,
New York
).
2.
Apoux
,
F.
, and
Bacon
,
S. P.
(
2004
). “
Relative importance of temporal information in various frequency regions for consonant identification in quiet and in noise
,”
J. Acoust. Soc. Am.
116
,
1671
1680
.
3.
Baskent
,
D.
(
2006
). “
Speech recognition in normal hearing and sensorineural hearing loss as a function of the number of spectral channels
,”
J. Acoust. Soc. Am.
120
,
2908
2925
.
4.
Bernstein
,
J. G.
, and
Oxenham
,
A. J.
(
2005
). “
An autocorrelation model with place dependence to account for the effect of harmonic number on fundamental frequency discrimination
,”
J. Acoust. Soc. Am.
117
,
3816
3831
.
5.
Breeuwer
,
M.
, and
Plomp
,
R.
(
1986
). “
Speechreading supplemented with auditorily presented speech parameters
,”
J. Acoust. Soc. Am.
79
,
481
499
.
6.
Brokx
,
J. P. L.
, and
Nooteboom
,
S. G.
(
1982
). “
Intonation and the perceptual separation of simultaneous voices
,”
J. Phonetics
10
,
23
36
.
7.
Dau
,
T.
,
Kollmeier
,
B.
, and
Kohlrausch
,
A.
(
1997
). “
Modeling auditory processing of amplitude modulation. I. Detection and masking with narrowband carriers
,”
J. Acoust. Soc. Am.
102
,
2892
2905
.
8.
de Boer
,
E.
(
1956
). “
Pitch of inharmonic signals
,”
Nature (London)
178
,
535
536
.
9.
Deeks
,
J. M.
, and
Carlyon
,
R. P.
(
2004
). “
Simulations of cochlear implant hearing using filtered harmonic complexes: Implications for concurrent sound segregation
,”
J. Acoust. Soc. Am.
115
,
1736
1746
.
10.
Dorman
,
M. F.
,
Loizou
,
P. C.
,
Fitzke
,
J.
, and
Tu
,
Z.
(
1998
). “
The recognition of sentences in noise by normal-hearing listeners using simulations of cochlear-implant signal processors with 6-20 channels
,”
J. Acoust. Soc. Am.
104
,
3583
3585
.
11.
Dorman
,
M. F.
,
Loizou
,
P. C.
, and
Rainey
,
D.
(
1997
). “
Speech intelligibility as a function of the number of channels of stimulation for signal processors using sine-wave and noise-band outputs
,”
J. Acoust. Soc. Am.
102
,
2403
2411
.
12.
Dorman
,
M. F.
,
Loizou
,
P. C.
,
Spahr
,
A. J.
, and
Maloff
,
E.
(
2002
). “
A comparison of the speech understanding provided by acoustic models of fixed-channel and channel-picking signal processors for cochlear implants
,”
J. Speech Lang. Hear. Res.
45
,
783
788
.
13.
Drullman
,
R.
,
Festen
,
J. M.
, and
Plomp
,
R.
(
1994a
). “
Effect of reducing slow temporal modulations on speech reception
,”
J. Acoust. Soc. Am.
95
,
2670
2680
.
14.
Drullman
,
R.
,
Festen
,
J. M.
, and
Plomp
,
R.
(
1994b
). “
Effect of temporal envelope smearing on speech reception
,”
J. Acoust. Soc. Am.
95
,
1053
1064
.
15.
Dudley
,
H.
(
1939
). “
Remaking speech
,”
J. Acoust. Soc. Am.
11
,
169
177
.
16.
Erber
,
N. P.
(
1969
). “
Interaction of audition and vision in the recognition of oral speech stimuli
,”
J. Speech Hear. Res.
12
,
423
425
.
17.
Faulkner
,
A.
,
Rosen
,
S.
, and
Smith
,
C.
(
2000
). “
Effects of the salience of pitch and periodicity information on the intelligibility of four-channel vocoded speech: Implications for cochlear implants
,”
J. Acoust. Soc. Am.
108
,
1877
1887
.
18.
Friesen
,
L. M.
,
Shannon
,
R. V.
,
Baskent
,
D.
, and
Wang
,
X.
(
2001
). “
Speech recognition in noise as a function of the number of spectral channels: Comparison of acoustic hearing and cochlear implants
,”
J. Acoust. Soc. Am.
110
,
1150
1163
.
19.
Fu
,
Q. J.
, and
Shannon
,
R. V.
(
2000
). “
Effect of stimulation rate on phoneme recognition by nucleus-22 cochlear implant listeners
,”
J. Acoust. Soc. Am.
107
,
589
597
.
20.
Fu
,
Q. J.
,
Shannon
,
R. V.
, and
Wang
,
X.
(
1998a
). “
Effects of noise and spectral resolution on vowel and consonant recognition: Acoustic and electric hearing
,”
J. Acoust. Soc. Am.
104
,
3586
3596
.
21.
Fu
,
Q. J.
,
Zeng
,
F. G.
,
Shannon
,
R. V.
, and
Soli
,
S. D.
(
1998b
). “
Importance of tonal envelope cues in Chinese speech recognition
,”
J. Acoust. Soc. Am.
104
,
505
510
.
22.
Füllgrabe
,
C.
,
Berthommier
,
F.
, and
Lorenzi
,
C.
(
2006
). “
Masking release for consonant features in temporally fluctuating background noise
,”
Hear. Res.
211
,
74
84
.
23.
Glasberg
,
B. R.
, and
Moore
,
B. C. J.
(
1990
). “
Derivation of auditory filter shapes from notched-noise data
,”
Hear. Res.
47
,
103
138
.
24.
Gonzales
,
J.
, and
Oliver
,
J. C.
(
2005
). “
Gender and speaker identification as a function of the number of channels in spectrally reduced speech
,”
J. Acoust. Soc. Am.
118
,
461
470
.
25.
Grant
,
K. W.
,
Braida
,
L. D.
, and
Renn
,
R. J.
(
1991
). “
Single band amplitude envelope cues as an aid to speechreading
,”
Q. J. Exp. Psychol. A
43A
,
621
645
.
26.
Grant
,
K. W.
,
Summers
,
V.
, and
Leek
,
M. R.
(
1998
). “
Modulation rate detection and discrimination by normal-hearing and hearing-impaired listeners
,”
J. Acoust. Soc. Am.
104
,
1051
1060
.
27.
Healy
,
E. W.
, and
Steinbach
,
H. M.
(
2007
). “
The effect of smoothing filter slope and spectral frequency on temporal speech information
,”
J. Acoust. Soc. Am.
121
,
1177
1181
.
28.
Hochmair
,
I.
,
Nopp
,
P.
,
Jolly
,
C.
,
Schmidt
,
M.
,
Schosser
,
H.
,
Garnham
,
C.
, and
Anderson
,
I.
(
2006
). “
MED-EL cochlear implants: State of the art and a glimpse into the future
,”
Trends Amplif.
10
,
201
219
.
29.
IEEE
(
1969
). “
IEEE recommended practice for speech quality measurements
,”
IEEE Trans. Audio Electroacoust.
AU-17
,
225
246
.
30.
Keppel
,
G.
(
1991
).
Design and Analysis: A Researcher’s Handbook
(
Prentice Hall
,
Upper Saddle River, NJ
).
31.
Kohlrausch
,
A.
,
Fassel
,
R.
, and
Dau
,
T.
(
2000
). “
The influence of carrier level and frequency on modulation and beat-detection thresholds for sinusoidal carriers
,”
J. Acoust. Soc. Am.
108
,
723
734
.
32.
Kong
,
Y. Y.
, and
Zeng
,
F. G.
(
2006
). “
Temporal and spectral cues in Mandarin tone recognition
,”
J. Acoust. Soc. Am.
120
,
2830
2840
.
33.
Kwon
,
B. J.
, and
Turner
,
C. W.
(
2001
). “
Consonant identification under maskers with sinusoidal modulation: Masking release or modulation interference?
,”
J. Acoust. Soc. Am.
110
,
1130
1140
.
34.
Kwon
,
B. J.
, and
van den Honert
,
C.
(
2006
). “
Effect of electrode configuration on psychophysical forward masking in cochlear implant listeners
,”
J. Acoust. Soc. Am.
119
,
2994
3002
.
35.
Laneau
,
J.
,
Wouters
,
J.
, and
Moonen
,
M.
(
2006
). “
Improved music perception with explicit pitch coding in cochlear implants
,”
Audiol. Neuro-Otol.
11
,
38
52
.
36.
Lawson
,
J. L.
, and
Uhlenbeck
,
G. E.
(
1950
).
Threshold Signals
,
Radiation Laboratory Series
Vol.
24
(
McGraw-Hill
,
New York
).
37.
Loizou
,
P. C.
,
Dorman
,
M.
,
Poroy
,
O.
, and
Spahr
,
T.
(
2000
). “
Speech recognition by normal-hearing and cochlear implant listeners as a function of intensity resolution
,”
J. Acoust. Soc. Am.
108
,
2377
2387
.
38.
Loizou
,
P. C.
,
Dorman
,
M.
, and
Tu
,
Z.
(
1999
). “
On the number of channels needed to understand speech
,”
J. Acoust. Soc. Am.
106
,
2097
2103
.
39.
Lorenzi
,
C.
,
Dumont
,
A.
, and
Füllgrabe
,
C.
(
2000
). “
Use of temporal envelope cues by children with developmental dyslexia
,”
J. Speech Lang. Hear. Res.
43
,
1367
1379
.
40.
Luo
,
X.
, and
Fu
,
Q. J.
(
2004
). “
Enhancing Chinese tone recognition by manipulating amplitude envelope: Implications for cochlear implants
,”
J. Acoust. Soc. Am.
116
,
3659
3667
.
41.
Moore
,
B. C. J.
(
2003a
). “
Coding of sounds in the auditory system and its relevance to signal processing and coding in cochlear implants
,”
Otol. Neurotol.
24
,
243
254
.
42.
Moore
,
B. C. J.
(
2003b
).
An Introduction to the Psychology of Hearing
, 5th ed. (
Academic
,
San Diego
).
43.
Moore
,
B. C. J.
, and
Carlyon
,
R. P.
(
2005
). “
Perception of pitch by people with cochlear hearing loss and by cochlear implant users
,” in
Pitch Perception
, edited by
C. J.
Plack
,
A. J.
Oxenham
,
R. R.
Fay
, and
A. N.
Popper
(
Springer
,
New York
).
44.
Moore
,
B. C. J.
,
Glasberg
,
B. R.
,
Low
,
K.-E.
,
Cope
,
T.
, and
Cope
,
W.
(
2006
). “
Effects of level and frequency on the audibility of partials in inharmonic complex tones
,”
J. Acoust. Soc. Am.
120
,
934
944
.
45.
Moore
,
B. C. J.
, and
Ohgushi
,
K.
(
1993
). “
Audibility of partials in inharmonic complex tones
,”
J. Acoust. Soc. Am.
93
,
452
461
.
46.
Nie
,
K.
,
Barco
,
A.
, and
Zeng
,
F. G.
(
2006
). “
Spectral and temporal cues in cochlear implant speech perception
,”
Ear Hear.
27
,
208
217
.
47.
Nilsson
,
M.
,
Soli
,
S. D.
, and
Sullivan
,
J. A.
(
1994
). “
Development of the Hearing In Noise Test for the measurement of speech reception thresholds in quiet and in noise
,”
J. Acoust. Soc. Am.
95
,
1085
1099
.
48.
Plomp
,
R.
(
1964
). “
The ear as a frequency analyzer
,”
J. Acoust. Soc. Am.
36
,
1628
1636
.
49.
Plomp
,
R.
(
1983
). “
The role of modulation in hearing
,” in
Hearing—Physiological Bases and Psychophysics
, edited by
R.
Klinke
and
R.
Hartmann
(
Springer
,
Berlin
).
50.
Qin
,
M. K.
, and
Oxenham
,
A. J.
(
2003
). “
Effects of simulated cochlear-implant processing on speech reception in fluctuating maskers
,”
J. Acoust. Soc. Am.
114
,
446
454
.
51.
Qin
,
M. K.
, and
Oxenham
,
A. J.
(
2005
). “
Effects of envelope-vocoder processing on f0 discrimination and concurrent-vowel identification
,”
Ear Hear.
26
,
451
460
.
52.
Qin
,
M. K.
, and
Oxenham
,
A. J.
(
2006
). “
Effects of introducing unprocessed low-frequency information on the reception of envelope-vocoder processed speech
,”
J. Acoust. Soc. Am.
119
,
2417
2426
.
53.
Rosen
,
S.
(
1992
). “
Temporal information in speech: Acoustic, auditory and linguistic aspects
,”
Philos. Trans. R. Soc. London, Ser. B
336
,
367
373
.
54.
Rosen
,
S. M.
,
Fourcin
,
A. J.
, and
Moore
,
B. C. J.
(
1981
). “
Voice pitch as an aid to lipreading
,”
Nature (London)
291
,
150
152
.
55.
Shannon
,
R. V.
(
1983
). “
Multichannel electrical stimulation of the auditory nerve in man. I. Basic psychophysics
,”
Hear. Res.
11
,
157
189
.
56.
Shannon
,
R. V.
(
1992
). “
Temporal modulation transfer functions in patients with cochlear implants
,”
J. Acoust. Soc. Am.
91
,
2156
2164
.
57.
Shannon
,
R. V.
,
Galvin
,
J. J.
, III
, and
Baskent
,
D.
(
2002
). “
Holes in hearing
,”
J. Assoc. Res. Otolaryngol.
3
,
185
199
.
58.
Shannon
,
R. V.
,
Zeng
,
F. G.
,
Kamath
,
V.
,
Wygonski
,
J.
, and
Ekelid
,
M.
(
1995
). “
Speech recognition with primarily temporal cues
,”
Science
270
,
303
304
.
59.
Smith
,
M. W.
, and
Faulkner
,
A.
(
2006
). “
Perceptual adaptation by normally hearing listeners to a simulated ‘hole’ in hearing
,”
J. Acoust. Soc. Am.
120
,
4019
4030
.
60.
Stickney
,
G. S.
,
Zeng
,
F. G.
,
Litovsky
,
R.
, and
Assmann
,
P.
(
2004
). “
Cochlear implant speech recognition with speech maskers
,”
J. Acoust. Soc. Am.
116
,
1081
1091
.
61.
Stone
,
M. A.
, and
Moore
,
B. C. J.
(
2003
). “
Effect of the speed of a single-channel dynamic range compressor on intelligibility in a competing speech task
,”
J. Acoust. Soc. Am.
114
,
1023
1034
.
62.
Studebaker
,
G.
(
1985
). “
A ‘rationalized’ arcsine transform
,”
J. Speech Hear. Res.
28
,
455
462
.
63.
Van Tasell
,
D. J.
,
Greenfield
,
D. G.
,
Logemann
,
J. J.
, and
Nelson
,
D. A.
(
1992
). “
Temporal cues for consonant recognition: Training, talker generalization, and use in evaluation of cochlear implants
,”
J. Acoust. Soc. Am.
92
,
1247
1257
.
64.
Van Tasell
,
D. J.
,
Soli
,
S. D.
,
Kirby
,
V. M.
, and
Widin
,
G. P.
(
1987
). “
Speech waveform envelope cues for consonant recognition
,”
J. Acoust. Soc. Am.
82
,
1152
1161
.
65.
Whitmal
,
N. A.
,
Poissant
,
S. F.
,
Freyman
,
R. L.
, and
Helfer
,
K. S.
(
2007
). “
Speech intelligibility in cochlear implant simulations: Effects of carrier type, interfering noise, and subject experience
,”
J. Acoust. Soc. Am.
122
,
2376
2388
.
66.
Xu
,
L.
,
Thompson
,
C. S.
, and
Pfingst
,
B. E.
(
2005
). “
Relative contributions of spectral and temporal cues for phoneme recognition
,”
J. Acoust. Soc. Am.
117
,
3255
3267
.
67.
Xu
,
L.
,
Tsai
,
Y.
, and
Pfingst
,
B. E.
(
2002
). “
Features of stimulation affecting tonal-speech perception: Implications for cochlear prostheses
,”
J. Acoust. Soc. Am.
112
,
247
258
.
68.
Xu
,
L.
, and
Zheng
,
Y.
(
2007
). “
Spectral and temporal cues for phoneme recognition in noise
,”
J. Acoust. Soc. Am.
122
,
1758
1764
.
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