Benefits of Cochlear Implantation and Hearing Preservation for Children with Preoperative Functional Hearing

There are two types of cochlear implants available on the market today. The traditional cochlear implant (CI) employs only electrical stimulation (ES) via an electrode array inserted into the cochlea, which directly stimulates the auditory nerve, bypassing damaged or missing hair cells. The second type of stimulation from an electrode array in a CI is less common; a hybrid CI or an electrical acoustical stimulation (EAS) electrode array. EAS is appropriate for patients who have a severe to profound high-frequency hearing loss but some useable lower-frequency hearing. EAS CIs received approval in the United States by the Food and Drug Administration in 2014.

Recently, researchers in Chapel Hill, North Carolina, completed a study comparing pre-activation and post-activation performance of 24 children on word and sentence recognition, speech production, prosodic identification, perceived hearing benefit, and other measures of language. The interval between testing was approximately 12 months. The children were placed into two groups. Children who had a low-frequency pure tone average (LFPTA) of better than 75 dB HL were implanted with an EAS CI. Children with a postoperative LFPTA of poorer than 75 dB HL were implanted with traditional ES programs.

Results indicated that all participants (both groups) showed significant improvement in word recognition scores from preoperative measures. In addition, there was a significant improvement in expressive language and articulation for all participants when comparing pre- and post-activation scores. Interestingly, children who received a CI utilizing EAS outperformed the ES users in identifying prosodic features and perceived hearing benefit. No differences in word or sentence recognition scores were measured between the two groups.

The authors concluded that all their subjects experienced a significant improvement in speech recognition, articulation, expressive language, and perceived abilities, regardless of type of stimulation, when compared to the preoperative abilities and perceptions. They summarized that children with normal-to-moderate low-frequency thresholds and severe-to-profound high-frequency thresholds benefit from a CI. They also supported the importance of hearing preservation during cochlear implantation (EAS), for the subjective perceived benefit and the improved ability to identify prosodic cues.

Reference

Park, L. R., Richter, M. E., Gagnon, E. B., Culbertson, S. R., Henderson, L. W., & Dillon, M. T. (2025). Benefits of cochlear implantation and hearing preservation for children with preoperative functional hearing: a prospective clinical trial. Ear & Hearing. In press.