Speech recognition performance in children with cochlear implants using bimodal stimulation

Bimodal Stimulation in Children With Bilateral Profound Sensorineural Hearing Loss: A Suitable Intervention Model for Children at the Early Developmental Stage

OBJECTIVE

To evaluate the auditory and speech benefit of bimodal stimulation for prelingual deafened cochlear implantation recipients.

STUDY DESIGN

Retrospective and comparative study.

SETTING

Tertiary referral center.

PATIENTS

Fifty-six children with bilateral prelingual profound sensorineural hearing loss were enrolled, including 28 consecutive children with unilateral cochlear implantation (CI group), and 28 consecutive children with bimodal stimulation (BI group) who used an additional hearing aid (HA) in the contralateral ear.

MAIN OUTCOME MEASURES

Hearing assessments included the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) and Categories of Auditory Performance (CAP). Speech evaluations included the Meaningful Use of Speech Scale (MUSS), and Speech Intelligibility Rating (SIR). These measurements were evaluated at the first mapping of cochlear implants and 0.5, 1, 3, 6, 12, 18, 24 months after. Data were analyzed by repeated measures analysis.

RESULTS

The mean ages of BI and CI groups were similar (17.6 ± 6.87 vs 19.0 ± 8.10 months, p = 0.497). The initial scores for hearing and speech assessments showed no differences between the two groups, apart from IT-MAIS (2.46 ± 0.631 in BI group vs 0.50 ± 0.279 in CI group, p = 0.004). The auditory and speech development over time were different in the two groups as seen in IT-MAIS (p < 0.001), CAP (p = 0.029), MUSS (p < 0.001), and SIR (p < 0.001). A continuing but stable difference was observed in CAP, MUSS, and SIR at 3, 18, and 12 months after the first mapping, respectively. In addition, the BI group had better IT-MAIS scores at 3 and 6 months compared with the CI group; however, the difference was not significant after 12 months.

CONCLUSION

Bimodal stimulation is beneficial for prelingually deafened CI recipients who have minimal contralateral residual hearing when bilateral CIs are not available. Hearing aid use in the contralateral ear might be recommended for children after unilateral cochlear implantation to facilitate the development of auditory and speech skills.

Early Speech Perception Test Outcome in Children with Severe Sensorineural Hearing Loss with Unilateral Cochlear Implants Alone versus Bimodal Stimulation

Bilateral stimulation of the auditory system has clear advantages over unilateral hearing. Hearing-impaired children are, therefore, generally fitted with hearing aids in both ears so that they can have the benefits of binaural hearing. Children who use acochlear implant in one ear and no acoustic stimulation in the opposite ear are at a definite disadvantage. This study was undertaken to determine the advantages of bimodal stimulation in pediatric population especially in terms of speech recognition. This study comprised of 30 children between 3 and 6 years of age with profound bilateral sensorineural hearing loss with cochlear implant in one ear and fitted with digital hearing aid in non-implanted ear. Speech recognition performance was compared in unilateral cochlear implant only and with bimodal hearing stimulation in the same set of children. A statistically significant difference was found between speech reception scores in children with a unilateral cochlear implant only and those with a cochlear implant in one ear and a hearing aid in the non implanted ear in quiet surroundings. It is suggested that the use of bimodal fitting be considered as an effective management method to obtain the advantage of binaural hearing in children who undergo unilateral cochlear implantation.

The Benefits of Residual Hair Cell Function for Speech and Music Perception in Pediatric Bimodal Cochlear Implant Listeners

Objective

The aim of this study was to investigate the benefits of residual hair cell function for speech and music perception in bimodal pediatric Mandarin-speaking cochlear implant (CI) listeners.

Design

Speech and music performance was measured in 35 Mandarin-speaking pediatric CI users for unilateral (CI-only) and bimodal listening. Mandarin speech perception was measured for vowels, consonants, lexical tones, and sentences in quiet. Music perception was measured for melodic contour identification (MCI).

Results

Combined electric and acoustic hearing significantly improved MCI and Mandarin tone recognition performance, relative to CI-only performance. For MCI, performance was significantly better with bimodal listening for all semitone spacing conditions (p < 0.05 in all cases). For tone recognition, bimodal performance was significantly better only for tone 2 (rising; p < 0.05). There were no significant differences between CI-only and CI + HA for vowel, consonant, or sentence recognition.

Conclusions

The results suggest that combined electric and acoustic hearing can significantly improve perception of music and Mandarin tones in pediatric Mandarin-speaking CI patients. Music and lexical tone perception depends strongly on pitch perception, and the contralateral acoustic hearing coming from residual hair cell function provided pitch cues that are generally not well preserved in electric hearing.

Emotional Perception of Music in Children With Bimodal Fitting and Unilateral Cochlear Implant

OBJECTIVE

Biological, structural, and acoustical constraints faced by cochlear implant (CI) users can alter the perception of music. Bimodal fitting not only provides bilateral hearing but can also improve auditory skills. This study was conducted to assess the impact of this amplification style on the emotional perception of music among children with hearing loss (HL).

METHODS

Twenty-five children with congenital severe to profound HL and unilateral CIs, 20 children with bimodal fitting, and 30 children with normal hearing participated in this study. Their emotional perceptions of music were measured using a method where children indicated happy or sad feelings induced by music by pointing to pictures of faces showing these emotions.

RESULTS

Children with bimodal fitting obtained significantly higher mean scores than children with unilateral CIs for both happy and sad music items and in overall test scores (P < .001). Both groups with HL obtained significantly lower scores than children with normal hearing (P < .001).

CONCLUSIONS

Bimodal fitting results in a better emotional perception of music compared to unilateral CI. Given the influence of music in neurological and linguistic development and social interactions, it is important to evaluate the possible benefits of bimodal fitting prescriptions for individuals with unilateral CIs.