The paper presents the effect of sound coding strategies on speech intelligibility of Thai-speaking cochlear implant (CI) users. Two sound coding strategies, namely continuous interleaved sampling (CIS) and advanced combination encoder (ACE) strategies were evaluated for word recognition. The tested words consisting of monosyllabic and bisyllabic words were corrupted by speech shaped noise and babble noise at SNR levels of 0, 5, 10 and 15 dB. The vocoded speech of clean and noisy words were tested by twelve normal-hearing listeners. The experimental results showed that speech intelligibility of the ACE strategy had higher mean scores than that of the CIS strategy in all tested conditions. The ACE strategy provided a significant speech intelligibility at SNR levels of 5 and 10 dB for monosyllabic words with speech shaped noise and at SNR levels of 0 dB for bisyllabic words with speech shaped noise. In addition, the noisy bisyllabic words provided higher intelligibility performance than the noisy monosyllabic words in all tested conditions.
Keywords: cochlear implant, sound coding, speech intelligibility, filter bank, hearing loss
Chen, F., & Loizou, P. C. (2011). Predicting the Intelligibility of Vocoded Speech. Ear and Hearing, 32(3), 331-338.
Cochlear. (2002). ACE™ and CIS DSP Strategies Software Requirements Specification,Part Number: N95287F Issue 1. Lane Cove, New South Wales: Australia.
Fan-Gang, Z., Rebscher, S., Harrison, W., Xiaoan, S., & Haihong, F. (2008). Cochlear implants: system design, integration, and evaluation. IEEE Reviews in Biomedical Engineering, 1(1), 115-142.
Kangsanarak, B. (1980). Development of Thai Spondee Words for Speech Audiometry. Mahidol University, Bangkok.
Kasemsuwan, L., Cheewaruangroj, W., Tungkeeratichai, J., Bhongmakapat, T., Thawin, C., Lertsukprasert, K., . . . Laothamatas, J. (2010). Fourteen-years experience with cochlear implantation in Ramathibodi Hospital. Journal of the Medical Association of Thailand, 93(12), 1399-1405.
Kiefer, J., Hohl, S., Sturzebecher, E., Pfennigdorff, T., & Gstoettner, W. (2001). Comparison of speech recognition with different speech coding strategies (SPEAK, CIS, and ACE) and their relationship to telemetric measures of compound action potentials in the nucleus CI 24M cochlear implant system. Audiology, 40(1), 32-42.
Komalarajun, S. (1979). Development of Thai Speech Discrimination Materials. Mahidol University, Bangkok.
Lin, Y.-H. (2013). The Sounds of Chinese. Cambridge: Cambridge University Press.
Liu, H., Peng, X., Zhao, Y., & Ni, X. (2017). The effectiveness of sound-processing strategies on tonal language cochlear implant users: A systematic review. Pediatric Investigation, 1, 35-42.
Loizou, P. C. (2006). Speech processing in vocoder-centric cochlear implants. In A. R. Moller (Ed.), Cochlear and Brainstem Implants, 13 July 2006 (pp. 109-143). Basel, Switzerland: Karger.
Nogueira, W., Buchner, A., Lenarz, T., & Edler, B. (2005). A psychoacoustic "NofM"-type speech coding strategy for cochlear implants. Eurasip Journal on Applied Signal Processing, 2005(18), 3044-3059.
Qin, M. K., & Oxenham, A. J. (2003). Effects of simulated cochlear-implant processing on speech reception in fluctuating maskers. Journal of the Acoustical Society of America, 114(1), 446-454.
Skinner, M. W., Holden, L. K., Whitford, L. A., Plant, K. L., Psarros, C., & Holden, T. A. (2002). Speech recognition with the nucleus 24 SPEAK, ACE, and CIS speech coding strategies in newly implanted adults. Ear and Hearing, 23(3), 207-223.
Theera-Umpon, N., Chansareewittaya, S., & Auephanwiriyakul, S. (2011). Phoneme and tonal accent recognition for Thai speech. Expert Systems with Applications, 38(10), 13254-13259.
Vaewvichit, K., & Luangpitakchumpol, P. (1999). Cochlear implantation in Thailand. The Journal of Laryngology & Otology, 113(6), 515-517.
Wilson, B. S. (2017). The cochlear implant and possibilities for narrowing the remaining gaps between prosthetic and normal hearing. World J Otorhinolaryngol Head Neck Surg, 3(4), 200-210.
Wilson, B. S., & Dorman, M. F. (2008). Cochlear implants: A remarkable past and a brilliant future. Hear Res, 242(1-2), 3-21.
Wilson, B. S., & Dorman, M. F. (2008). Cochlear implants: Current designs and future possibilities. Journal of Rehabilitation Research and Development, 45(5), 695-730.
Wouters, J., McDermott, H. J., & Francart, T. (2015). Sound coding in cochlear implants: from electric pulse to hearing. IEEE Signal Processing Magazine, 32(2), 67-80.
Xu, L., & Zhou, N. (2011). Tonal Languages and Cochlear Implants. Auditory Prostheses, 39, 341-364.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.