There is a systematic relationship between stress accent and vocalic identity in spontaneous English discourse (the Switchboard corpus composed of telephone dialogues). Low vowels are much more likely to be fully accented than their high vocalic counterparts. And conversely, high vowels are far more likely to lack stress accent than low or mid vocalic segments. Such patterns imply that stress accent and vocalic identity (particularly vowel height) are bound together at some level of lexical representation. Statistical analysis of a manually annotated corpus (Switchboard) indicates that vocalic duration is likely to serve as an important acoustic cue for stress accent, particularly for diphthongs and the low, tense monophthongs. In addition , multilayer perceptrons (MLPs) were trained on a portion of this annotated material in order to automatically label the corpus with respect to stress accent. The automatically derived labels are highly concordant with those of human transcribers (79% concordance within a quarter-step of accent level and 97.5% concordant within a half-step of accent level). In order to achieve such a high degree of concordance it is necessary to include features pertaining not only to the duration and amplitude of the vocalic nuclei, but also those associated with speaker gender, syllabic duration and most importantly, vocalic identity. Such results suggest that vocalic identity is intimately associated with stress accent in spontaneous American English (and vice versa), thereby providing a potential foundation with which to model pronunciation variation for automatic speech recognition.
[1]
D. Fry.
Experiments in the Perception of Stress
,
1958
.
[2]
F. L. Sack.
English Word-Stress
,
1969
.
[3]
Dick R. van Bergem,et al.
Acoustic vowel reduction as a function of sentence accent, word stress, and word class
,
1993,
Speech Commun..
[4]
Steven Greenberg,et al.
AN INTRODUCTION TO THE DIAGNOSTIC EVALUATION OF SWITCHBOARD-CORPUS AUTOMATIC SPEECH RECOGNITION SYSTEMS
,
2000
.
[5]
Lou Boves,et al.
Acoustic characteristics of lexical stress in continuous telephone speech
,
1999,
Speech Commun..
[6]
S. Greenberg,et al.
Automatic Detection of Prosodic Stress in American English Discourse
,
2000
.
[7]
B. Lindblom.
Spectrographic Study of Vowel Reduction
,
1963
.
[8]
G. E. Peterson,et al.
Duration of Syllable Nuclei in English
,
1960
.
[9]
Steven Greenberg,et al.
Vowel height is intimately associated with stress accent in spontaneous american English discourse
,
2001,
INTERSPEECH.
[10]
H Hermansky,et al.
Perceptual linear predictive (PLP) analysis of speech.
,
1990,
The Journal of the Acoustical Society of America.
[11]
John W. Black,et al.
Natural Frequency, Duration, and Intensity of Vowels in Reading
,
1949
.
[12]
Steven Greenberg,et al.
PROSODIC STRESS REVISITED: REASSESSING THE ROLE OF FUNDAMENTAL FREQUENCY
,
2000
.
[13]
A. C. Gimson,et al.
An introduction to the pronunciation of English
,
1991
.