Currently, an option of care for profoundly hard-of-hearing individuals that qualify has been a unilateral CI (UCI), the implantation of one ear only saving the other ear for future medical advancements. A substantial body of research has demonstrated that pre-lingual hard-of-hearing children are able to develop significant speech production skills through the use of a single CI (Geers, 1997; Geers & Tobey, 1995; Miyamoto, Kirk, Robbins, Todd & Riley, 1996; Tobey & Geers, 1995; Tobey, Geers, Brenner, Altuna & Gabbert, 2003). For example, some of the advantages observed in a case study of a single CI included an increase in speech and eligibility, an increased receptor vocabulary, a decrease in production of non-words, and increased response to questions (Ertmer, Strong, & Sadagopan, 2003).
Although the advantages of a UCI greatly increase the ability of the student to obtain speech, the risks associated with unilateral hearing loss (UHL), either natural or through the use of a UCI, have been well documented in the literature. Specifically, students who experience a degree of UHL are at a higher risk for educational, speech–language, and social–emotional difficulties than that of their normal hearing (NH) peers. (Bess & Tharpe, 1984, 1986; English & Church, 1999; Oyler, Oyler & Martkin, 1988). UHL contributes to a significant risk for reading difficulties and as previously stated, studies have shown that high school graduates with hearing loss fall between the fourth and fifth grade reading level (Carney & Moeller, 1998; Traxler, 2000; Easterbrooks, et. al, 2008). Peters noted in the article, Rational for Bilateral Cochlear Implants, that children experiencing UHL are 10 times more likely to fail a grade or need additional educational resource assistance and are twice as likely to exhibit behavior difficulties in the classroom (Peters, 2006).
The case for bilateral cochlear implants has been made based on the concept of normal hearing that is binaural. In recent years the number of cochlear implants bilaterally implanted into children have significantly increased. As of October 2005, according to the review of three major implant manufacturers, there are approximately 2803 bilaterally implanted individuals worldwide (Peters, 2006). Approximately, 58% or 1402, of these implanted individuals are children (Peters, 2006). The used of binaural CIs allow the implant user to more closely mimic normal hearing. The normal hearing brain uses rapid, real-time analysis of signals from two ears combined with data to hear. (Peters, 2006). A review of the limited literature on BCIs has shown advantages for many individuals in the areas of improve speech recognition, sound localization, and reduced head shadowing effect (Litovsky, Parkinson, Araroli, Peters, Lake, Johnstone, & Yu, 2004; Peters, 2006).
Makes one begin to think that access to binural sound can present a significant advantage to students in comparison to those who only have access to sound unilaterally. The jury is still out on this one...
References
- Bess, F. H., & Tharpe, A. M., (1986). Case history data on unilaterally hearing impaired children. Ear and Hearing, 17 (1), 1 -11.
- Carney, A. E., & Moeller, M. P., (2003). Treatment efficacy: Hearing loss in children. Journal of Speech, Language and Hearing Research, 41, S61-S84.
- Easterbrooks, S. R., Lederberg, A. R., Miller, E. M., Bergeron, J. P., & McDonald-Connor, C. (2008). Emergent literacy skills during early childhood in children with hearing loss: Strengths and weaknesses. The Volta Review, 108 (2), 91-114.
- English, K., & Church, G. (1999). Unilateral hearing loss in children: An update from the 1990s. Language, Speech, and Hearing Services in Schools, 30, 26-31.
- Ertmer, D. J., Strong, L. M., & Sadagopan, N. (2003). Beginning to communicate after cochlear implantation: oral language development in a young child. Journal of Speech, Language, and Hearing Research, 46, 328-340.
- Geers, A. E., (1997). Comparing implants with hearing aids in profoundly deaf children. Otolaryngology and Head and Neck Surgery, 117, 150-154.
- Geers, A. E., Tobey, E. A. (1995). Longitudinal comparison of the benefits of cochlear implants and tactile aids in controlled educational settings. The Annals of Otology, Rhinology, & Laryngology, 166, 328S – 329S
- Litovsky, R. Y., Parkinson, A., Arcaroli, J., Peters, R., Lake, J., Johnston, P., & Yu, G. (2004). Bilateral cochlear implants in adults and children. Arch Otolaryngol Head and Neck Surg., 130, 648 – 655.
- Mitchell, R. E., & Karchmer, M. A. (2004). Chasing the mythical ten percent: Parental hearing status of deaf and hard of hearing students in the United States. Sign Language Studies, 4(2), 138-163.
- Miyamoto, R. T., Kirk, K. I., Robbins, A. M., Todd, S., & Riley, A. (1996). Speech perception and speech production skills of children with multichannel cochlear implants. Acta oto-Laryngologica, 116, 240-243.
- Nicholas, J. G. & Geers, A. E. (2007). Will they catch up? The role of age at cochlear implantation in the spoken language development of children with severe to profound hNicholas, J. G. & Geers, A. E. (2007). Will they catch up? The role of age at cochlear implantation in the spoken language development of children with severe to profound hearing loss. Journal of Speech, Language, and Hearing Research, 50, 1048-1062.
- Oyler, R. F., Oyler, A. L. & Matkin, N. D. (1988). Unilateral hearing losses: Demographic and educational impact. Language, Speech Hearing Services in Schools, 19, 201-209.
- Peters, R. P. (2006). Rationale for Bilateral Cochlear Implantation in Children and Adults. Retrieved March 2006, from http://www.cochlearamericas.com/PDFs/bilateral_white_paper.pdf.
- Robbins, A. M., Kock, D. B., Osberger, M. J., Zimmerman-Phillips, S., Kishon-Rabin, L. (2004). Effect of age at cochlear implantation on auditory skill development in infants and toddlers. Archives of Otolaryngology – Head and Neck Surgery, 130, 570 – 574.
- Tobey, E. A., & Geers, A. E. (1995). Speech production benefits of cochlear implants. Advances in Oto-Rhino-Laryngology, 50, 146-153.
- Tobey, E. A., Geers, A. E., Brenner, C. B., Altuna, D., & Gabbet, G. (2003). Factors associated with development of speech production skills in children by age five. Ear and Hearing, 24, 36S-45S.