Acoustic plus electric speech processing: Long-term results

Objective

Few studies have investigated the stability of residual hearing and speech perception outcomes in individuals who were implanted with a shorter electrode device.

Study Design

Longitudinal, single-subject design.

Methods

Fifty subjects who received a Nucleus Hybrid (Cochlear, Sydney, Australia) short electrode cochlear implant (CI) and had a minimum of 2 years (and up to 15 years) of postoperative longitudinal experience were included in this study. Twenty-three subjects received a Nucleus Hybrid S8 (S8); 14 subjects received a Nucleus Hybrid L24 (L24); and 13 received a Nucleus Hybrid S12 (S12). Audiometric thresholds and consonant-nucleus-consonant (CNC) words were collected pre- and postoperatively for up to 15 years for the S8 subjects and for up to 7 years for the S12 and L24 subjects. AzBio Sentences in multi-talker babble was collected for up to 7 years on the S12 and L24 subjects.

Results

Longitudinally, 83% of the S8 subjects, 92% of the S12 subjects, and 86% of the L24 subjects maintained a functional hearing pure-tone average (PTA) (125–500 Hz). Predicted change using a piecewise linear mixed model in PTA over time showed a postoperative linear decrease in hearing for each group until 0.5 years, after which the PTA stabilizes and is maintained. The averaged individual data for CNC and AzBio sentences show a significant improvement in scores by 0.25 to 0.5 years postimplantation, after which scores start to reach their maximum.

Conclusion

This long-term study demonstrates that acoustic-electric processing hearing and improvement in speech understanding in quiet and in noise can be accomplished and sustained for many years with a short electrode CI.

Level of Evidence

2C. Laryngoscope, 2017

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