Mario A Svirsky1,2,3, Nicole Hope Capach1,2, Jonathan D Neukam1,2, Mahan Azadpour1,2, Elad Sagi1,2, Ariel Edward Hight1,2, E Katelyn Glassman1,4, Annette Lavender1,5, Keena P Seward1,6, Margaret K Miller1,7, Nai Ding1,8, Chin-Tuan Tan1,9,10, Matthew B Fitzgerald1,11. 1. New York University. 2. Department of Otolaryngology Head and Neck Surgery, New York University Grossman School of Medicine, New York, New York. 3. Neuroscience Institute, New York University School of Medicine. 4. MED-EL USA, Durham, North Carolina. 5. Cochlear Americas, Denver, Colorado. 6. 3L Therapy Solutions, LLC, Beltsville, Maryland. 7. Human Auditory Development Lab, Boys Town National Research Hospital, Omaha, Nebraska, USA. 8. College of Biomedical Engineering and Instrument Sciences, Zhejiang University, Zhejiang, China. 9. Erik Jonsson School of Engineering and Computer Science. 10. Department of Speech and Hearing, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas. 11. Department of Otolaryngology Head and Neck Surgery, Stanford University, Stanford, California, USA.
Abstract
HYPOTHESIS: This study tests the hypothesis that it is possible to find tone or noise vocoders that sound similar and result in similar speech perception scores to a cochlear implant (CI). This would validate the use of such vocoders as acoustic models of CIs. We further hypothesize that those valid acoustic models will require a personalized amount of frequency mismatch between input filters and output tones or noise bands. BACKGROUND: Noise or tone vocoders have been used as acoustic models of CIs in hundreds of publications but have never been convincingly validated. METHODS: Acoustic models were evaluated by single-sided deaf CI users who compared what they heard with the CI in one ear to what they heard with the acoustic model in the other ear. We evaluated frequency-matched models (both all-channel and 6-channel models, both tone and noise vocoders) as well as self-selected models that included an individualized level of frequency mismatch. RESULTS: Self-selected acoustic models resulted in similar levels of speech perception and similar perceptual quality as the CI. These models also matched the CI in terms of perceived intelligibility, harshness, and pleasantness. CONCLUSION: Valid acoustic models of CIs exist, but they are different from the models most widely used in the literature. Individual amounts of frequency mismatch may be required to optimize the validity of the model. This may be related to the basalward frequency mismatch experienced by postlingually deaf patients after cochlear implantation.
HYPOTHESIS: This study tests the hypothesis that it is possible to find tone or noise vocoders that sound similar and result in similar speech perception scores to a cochlear implant (CI). This would validate the use of such vocoders as acoustic models of CIs. We further hypothesize that those valid acoustic models will require a personalized amount of frequency mismatch between input filters and output tones or noise bands. BACKGROUND: Noise or tone vocoders have been used as acoustic models of CIs in hundreds of publications but have never been convincingly validated. METHODS: Acoustic models were evaluated by single-sided deaf CI users who compared what they heard with the CI in one ear to what they heard with the acoustic model in the other ear. We evaluated frequency-matched models (both all-channel and 6-channel models, both tone and noise vocoders) as well as self-selected models that included an individualized level of frequency mismatch. RESULTS: Self-selected acoustic models resulted in similar levels of speech perception and similar perceptual quality as the CI. These models also matched the CI in terms of perceived intelligibility, harshness, and pleasantness. CONCLUSION: Valid acoustic models of CIs exist, but they are different from the models most widely used in the literature. Individual amounts of frequency mismatch may be required to optimize the validity of the model. This may be related to the basalward frequency mismatch experienced by postlingually deaf patients after cochlear implantation.
Authors: Mario A Svirsky; Matthew B Fitzgerald; Arlene Neuman; Elad Sagi; Chin-Tuan Tan; Darlene Ketten; Brett Martin Journal: J Am Acad Audiol Date: 2012-06 Impact factor: 1.664
Authors: Michael F Dorman; Sarah C Natale; Daniel M Zeitler; Leslie Baxter; Jack H Noble Journal: J Speech Lang Hear Res Date: 2019-08-15 Impact factor: 2.297