Overview. The overall goal of the self-hearing research program is to examine the individual's ability to hear his or her own speech while using hearing technology (HT). Currently, there are no clinical protocols for assessing self-hearing needs in fitting HT, and consequently, no guidelines to match HT to self-hearing needs are available (e.g., in selecting microphone directionality or signal processing parameters such as gain, compression thresholds, compression ratios, etc.). Yet both research and anecdotal evidence indicate that self-hearing is important to the HT user's experience and function, and HT may introduce changes to speech feedback (delays, occlusion, loudness distortions) that are detrimental to its perceived quality and the overall satisfaction with the HT. Our studies use psychoacoustic procedures to measure two aspects of speech feedback perception while speaking: loudness of the feedback, and salience of a feedback delay; and investigate the effects of various potentially significant factors related to HT (e.g., microphone directionality, compression algorithms, HA earmold type) and communication conditions (e.g., the level and type of background noise). The studies provide empirical data on the factors that influence HT users' self-hearing, information that is essential for further maximizing hearing aid and cochlear implant fittings and the resulting benefits.
Facilities. The facilities include a double-walled sound treated audiometric test booth with an adjacent control/monitoring room, and workspace for research assistants. Kyma sound design environment (Symbolic Sound Inc.) is used for real-time signal processing and coordination of various aspects of the experimental procedures (prompts and stimulus presentation, response recording). Sound recording and analysis is conducted using Pulse analyzer platform (Brüel & Kjær). In addition to the custom-designed software, publicly/commercially available software is used for sound analysis and manipulation (Praat, Adobe Audition, Audacity), and data analysis and presentation (SPSS, GraphPad Prism, R, LISREL). Other equipment includes multiple computers (both PC and Macintosh), microphones, insert headphones, amplifiers. Access to an audiometer, a tympanometer, a hearing-aid verification system is available in the shared research area.
People. The laboratory is directed by Dragana Barac-Cikoja, Ph.D. It was developed with the grant from the Department of Education, National Institute on Disability and Rehabilitation Research (NIDRR grant number HI33E080006). Collaborators include Kevin Cole (NOVA Web Development), software developer; Carla Scaletti (Symbolic Sound Corporation), Mathew Bakke (Gallaudet University), Linda Kozma-Spytek (Gallaudet University), Peggy Nelson (University of Minnesota), Liz Anderson (Envoy Medical Corp.). Cara Johnson, Natalye Faison, Stephanie Adamovich, Jose Reyes III, Sarah Sonnemann, Stephanie Karch, Melisa Kokx-Ryan, Lucas Lancaster, Ashley Zaleski, Monica Majewski, Whitney Kidd, Rebecca Kingman, Kasheen Schltz, and Jill Barney (graduate students in the HSLS department) have served as research assistants.
Selected publications and presentations.
Barac-Cikoja, D., Schultz, K., Barney, J., Kingman, R.. (March, 2015). Perception of Own Voice Relative Loudness at Different Speaking Levels. American Auditory Society Scientific and Technical Meeting, Scottsdale, AZ.
Barac-Cikoja, D., Majewski, M., Morgan, C. & Kidd, W. (2013). Relative loudness of high-pass filtered speech during speech production. American Auditory Society Scientific and Technology Conference, Scottsdale, AZ.
Roush, K., Zaleski, A., Kokx, M., Majewski, M. & Barac-Cikoja, D. (2012). Effects of compression on amplification of one's own voice: Investigation of real ear to coupler differences for varied degrees of hearing loss. International Hearing Aid Research Conference (IHCON), Lake Tahoe, CA.
Barac-Cikoja, D., Roush, K., Kokx, M., Lancaster, L. & Zaleski, A. (2012). Hearing aid users' perception of own voice relative loudness. American Auditory Society Scientific and Technology Conference, Scottsdale, AZ.
Barac-Cikoja, D. & Karch, S. (2011). Delay detection thresholds for speech feedback. Invited presentation at the American Auditory Society Scientific and Technology Conference, Scottsdale, AZ.
Barac-Cikoja, D. & Reyes, J.N. (2010). Effects of Earmold Style on Live Speech: In-the-Canal Measurements. American Auditory Society Scientific and Technology Conference, Scottsdale, AZ.