The overall aim of our research is to establish whether speech production goals for fricatives are articulatory, aerodynamic, aeroacoustic, or acoustic. The results of this work are also expected to have implications for the general theory of the goals of speech production, since fricative properties are a superset of the properties of other segments. In the initial experiments we explore whether goals for fricatives are aerodynamic by examining initiation and maintenance of turbulence, and interactions of the voicing and noise sources. The next set of experiments explores whether the goals for fricatives are aeroacoustic by examining cases in which the aeroacoustic source changes significantly as a result of minor articulatory changes. The following set of experiments explores acoustic goals by examining differences in control of the acoustic vocal-tract filter in voiced and voiceless fricatives. We distinguish between aeroacoustic and acoustic goals based on whether the goal concerns the properties of the sound source (aeroacoustic) or the filter (acoustic). If fricatives prove to have none of these goals, we will conclude that the goals are articulatory only, and will examine possible articulatory tradeoffs. Finally, we explore the ways in which goals for contiguous fricatives interact in fricative clusters. For all of these experiments we use three main experimental domains: mechanical models of the vocal tract in which articulatory and aerodynamic variables can be precisely controlled, computer simulations of acoustic, aerodynamic and aeroacoustic phenomena in the vocal tract with which similarity classes can be explored, and articulatory, aerodynamic and acoustic measurements of human subjects, which will serve to validate the models and simulations. We expect our research to contribute usefully to the debate about speech production, to advance our understanding of disfluencies involving fricative pronunciation, to broaden the range of analysis and simulation tools used for fricatives by the speech community, and to extend basic research on fricative production.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
1R01DC006705-01
Application #
6768145
Study Section
Motor Function, Speech and Rehabilitation Study Section (MFSR)
Program Officer
Shekim, Lana O
Project Start
2004-09-01
Project End
2009-07-31
Budget Start
2004-09-01
Budget End
2005-07-31
Support Year
1
Fiscal Year
2004
Total Cost
$290,811
Indirect Cost
Name
Haskins Laboratories, Inc.
Department
Type
DUNS #
060010147
City
New Haven
State
CT
Country
United States
Zip Code
06511
Koenig, Laura L; Shadle, Christine H; Preston, Jonathan L et al. (2013) Toward improved spectral measures of /s/: results from adolescents. J Speech Lang Hear Res 56:1175-89
Iskarous, Khalil; Shadle, Christine H; Proctor, Michael I (2011) Articulatory-acoustic kinematics: the production of American English /s/. J Acoust Soc Am 129:944-54
Proctor, Michael I; Shadle, Christine H; Iskarous, Khalil (2010) Pharyngeal articulation in the production of voiced and voiceless fricatives. J Acoust Soc Am 127:1507-18
Iskarous, Khalil (2005) Detecting the edge of the tongue: a tutorial. Clin Linguist Phon 19:555-65