Our Research

Clear Speech | Interpreter Intelligibility | EIPA-CS

Clear Speech

Clear speech refers to a speaking style that is significantly more intelligible than conversational speech for a variety of listeners and backgrounds such as noise and reverberation. Although typically spoken more slowly than conversational speech, talkers can produce clear speech at normal rates with training. By examining the acoustics of this form of clear speech (clear/normal speech) and the extent to which it preserves the widespread intelligibility benefits of clear (clear/slow) speech, our goal is to identify acoustic characteristics of highly intelligible speech and to determine the extent to which those characteristics differ for various populations and listening situations. Such information should not only suggest potential signal processing techniques for hearing aids but also increase our basic understanding of speech reception.

Selected Publication(s):

Jean C. Krause and Louis D. Braida (2004). “Acoustic properties of naturally produced clear speech at normal speaking rates,” J. Acoust. Soc. Am., Vol. 115, No. 1, pp. 362-378.

Jean C. Krause and Louis D. Braida (2002). “Investigating alternative forms of clear speech: The effects of speaking rate and speaking mode on intelligibility,” J. Acoust. Soc. Am., Vol. 112, No. 5, pp. 2165-2172.

Interpreter Intelligibility

Although it is common practice for deaf individuals to use interpreters as a means of accessing spoken information, little is known about interpreter intelligibility (amount of message correctly transmitted to deaf individuals who use interpreters) or the factors that govern interpreter intelligibility. This information is essential for characterizing the level of communication access afforded to deaf individuals by interpreters and could be of particularly serious consequence for deaf children still in the process of acquiring language. Our work in this area is aimed at quantifying relationships between interpreter intelligibility and specific physical characteristics of the visual signal produced by interpreters. While many such relationships have been specified for speech, the factors that govern the intelligibility of American Sign Language (ASL) and other English-based visual communication methods are largely unknown. In this project, we begin to examine these relationships for three English-based visual communication modes: Conceptually Accurate Signed English (CASE), Signing Exact English (SEE), and Cued Speech (CS). Specifically, we explore how the accuracy (percent of the spoken message correctly produced) and lag time (interval between spoken and visual message) of the visual message as well as the rate at which it is presented affect an interpreter's (i.e. transliterator's) intelligibility. Results will establish characteristics of highly intelligible transliterators, an important first step toward long-term goals aimed at improving: 1) transliterator training and services, 2) communication access for deaf individuals who use transliterators, and 3) scientific understanding of intelligibility in the visual modality and perception across all modes of sensory communication.

Selected Publication(s):

Katherine Pelley, Dana Husaim, Morgan Tessler, Jessica Lindsay, and Jean Krause (2006). "The Effect of Speaking Rate amd Experience on Cued Speech Transliterator Accuracy," ASHA Convention, November 2006, Miami, FL (poster).

Educational Interpreter Performance Assessment for Cued Speech transliterators (EIPA-CS)

The Educational Interpreter Performance Assessment (EIPA) represents the first large-scale attempt to evaluate competencies of educational interpreters and to provide them with diagnostic feedback for improving their skills. It currently covers a wide variety of educational interpreting situations, offering tests at two grade levels (elementary and secondary) for three communication options (American Sign Language, Pidgin Signed English, and Signed Exact English). In this project, a pilot EIPA test was designed and developed for the Cued Speech communication option. Currently, the EIPA Diagnostic Center at Boys Town National Research Hospital (BTNRH) is reviewing this new tool, which has received endorsement from the National Cued Speech Association (see Press Release - 6/25/08 [PDF]). If the EIPA-CS is adopted by BTNRH, the applicability of the EIPA will be extended to Cued Speech transliterators.

Selected Publication(s):

Jean C. Krause, Judy A. Kegl, and Brenda Schick (2008). “Toward Extending the Educational Interpreter Performance Assessment to Cued Speech,” J. Deaf Stud. Deaf Educ., Vol. 13, No. 3, pp. 432-450.