Yoon Joo Shim

Comparison of speech recognition : ability with different speech processing strategies by Korean cochlear implantees

Many variables affect the audiologic performance of cochlear implantees. With current methods of evaluation, it is difficult to directly compare auditory function with different speech coding strategies. We compared the audiologic performance directly with F0F1F2 and multipeak speech coding strategies in the same implanted ear of eight Korean cochlear implantees. We tested word and phoneme recognition abilities using Korean word lists for speech audiometry and two-syllable nonsense words, respectively. With the multipeak coding strategy, a significant difference in discrimination ability was found in the initial fricative consonant phonemes (/s/, /ss/, /h/). Our results suggest that the improvement of speech recognition ability with the multipeak coding strategy comes primarily from the better understanding of the initial fricative consonants.

The evaluation of cognitive abilities in persons with cochlear implants

The results show the cochlear implant children’s ability to comprehend both English and Filipino questions and articulate answers, albeit on different levels of competence. The results are important for decision making prior to cochlear implantation in bilingual societies such as countries like the Philippines, Malaysia and South Africa, as well as immigrant groups in other countries. Therapy in a language different to the home language seems to encourage informal language acquisition similar to hearing children.

YUMC protocol of rehabilitation in cochlear implantees

Our preoperative evaluations include unaided and aided pure tone thresholds, speechrecognition test, speech and language evaluation, and cognitive evaluation, since these measures improve over time through the use of a cochlear implant. To monitor the improvements of these measures after implantation, we do routine re-evaluations of the preoperative tests every 6 months, as well as speech/language/auditory training to accelerate these abilities. Our new applications include the modified Neural Response Telemetry (NRT) strategy yielding T-NRTs similar to subjective T-levels, computerized system of speech recognition tests, Kaufman Assessment Batteries for Children (K-ABC; Moon and Byun, 1997), a new method of consonant classification (Shim et al., 2002), new strategies of speech correction for the prelingual congenitally deafened children and adult implantees (Shim et al., 2002). Our standardized speech and language evaluations include two types of receptive expressive language scales of language ages under 6 years of age, namely Korean version of the Receptive-Expressive Emergent Language Scale (Bzoch and League, 1971) and Preschool Receptive-Expressive Language Scale (Kim et al., 2003), and age appropriate vocabulary tests, namely Korean versions of Peabody Picture Vocabulary test (Kim et al., 1995) and Boston Naming test (Kaplan et al., 1993).

The benefit of cochlear implantation in high-frequency aided impairment: language and cognitive improvements in a 3-year-old child.

Even though speech and language, cognitive ability as well as speech-recognition ability are affected by the degrees of aided pure tone thresholds, no definite evidence regarding these measures nor any guidelines regarding the degree of aided pure tone thresholds have been reported concerning candidacy for cochlear implantation. The purpose of this paper is to present the evidence regarding the improvement of speech and language and cognitive abilities after cochlear implantation in high-frequency aided impairment.

Relationship between cognitive abilities and language development in children with cochlear implants.

(2004). Relationship between cognitive abilities and language development in children with cochlear implants. Cochlear Implants International: Vol. 5, No. sup1, pp. 143-145.