A thorough understanding of the abilities of normal- hearing and hearing-impaired individuals to process the spectral-temporal properties of speech is needed. In particular, the relation between the basic capabilities of the auditory system to resolve the acoustic details of speech and the perception of speech in normal discourse is poorly understood. Our research program directly addresses this need in three lines of research within a general theory of vowel perception. Listeners are selected to be typical of the population with either normal hearing or mild-to-moderate high-frequency sensorineural hearing impairment. The first line of research will determine the weighted contribution of three salient acoustic properties to the classification of American English vowels. This research explores the use of these properties in the identification of natural vowels in optimal conditions and in several conditions of distortion, including vowels presented in noise and vowels spoken with a foreign accent. The second line of research uses psychophysical techniques to determine listeners' thresholds for discriminating acoustic differences between vowels, including modeling of the peripheral auditory processing of these complex sounds. In addition, this research investigates the manner in which discrimination performance is degraded as experimental tasks change from those used in psychophysical procedures to those that simulate communication with natural sentences. In the third line of research, the relation between discrimination abilities and vowel classification in fluent speech will be determined. These experiments will describe systematically the relation between peripheral capabilities to process vowels and the more central processes of vowel classification in ordinary discourse. Results will also make major advances towards a new theory of vowel perception. The data from these experiments will contribute to the understanding of the impact of cochlear dysfunction on normal conversation processes.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC002229-06
Application #
6489529
Study Section
Special Emphasis Panel (ZRG1-IFCN-6 (01))
Program Officer
Shekim, Lana O
Project Start
1995-01-01
Project End
2004-12-31
Budget Start
2002-01-01
Budget End
2002-12-31
Support Year
6
Fiscal Year
2002
Total Cost
$156,125
Indirect Cost
Name
Indiana University Bloomington
Department
Other Health Professions
Type
Schools of Arts and Sciences
DUNS #
006046700
City
Bloomington
State
IN
Country
United States
Zip Code
47401
Morgan, Shae D; Ferguson, Sarah Hargus (2017) Judgments of Emotion in Clear and Conversational Speech by Young Adults With Normal Hearing and Older Adults With Hearing Impairment. J Speech Lang Hear Res 60:2271-2280
Ferguson, Sarah Hargus; Quené, Hugo (2014) Acoustic correlates of vowel intelligibility in clear and conversational speech for young normal-hearing and elderly hearing-impaired listeners. J Acoust Soc Am 135:3570-84
Ferguson, Sarah Hargus (2012) Talker differences in clear and conversational speech: vowel intelligibility for older adults with hearing loss. J Speech Lang Hear Res 55:779-90
Bent, Tessa; Kewley-Port, Diane; Ferguson, Sarah Hargus (2010) Across-talker effects on non-native listeners' vowel perception in noise. J Acoust Soc Am 128:3142-51
Fogerty, Daniel; Kewley-Port, Diane (2009) Perceptual contributions of the consonant-vowel boundary to sentence intelligibility. J Acoust Soc Am 126:847-57
Lee, Jae Hee; Kewley-Port, Diane (2009) Intelligibility of interrupted sentences at subsegmental levels in young normal-hearing and elderly hearing-impaired listeners. J Acoust Soc Am 125:1153-63
Oglesbee, Eric; Kewley-Port, Diane (2009) Estimating vowel formant discrimination thresholds using a single-interval classification task. J Acoust Soc Am 125:2323-35
Nishi, Kanae; Kewley-Port, Diane (2008) Nonnative speech perception training using vowel subsets: effects of vowels in sets and order of training. J Speech Lang Hear Res 51:1480-93
Nishi, Kanae; Kewley-Port, Diane (2007) Training Japanese listeners to perceive American English vowels: influence of training sets. J Speech Lang Hear Res 50:1496-509
Liu, Chang; Kewley-Port, Diane (2007) Factors affecting vowel formant discrimination by hearing-impaired listeners. J Acoust Soc Am 122:2855-64

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