Investigation of the effect of cochlear implant electrode length on speech comprehension in quiet and noise compared with the results with users of electro-acoustic-stimulation, a retrospective analysis

• Published in: PloS one Vol. 12; no. 5; p. e0174900
• Main Authors: Büchner, Andreas, Illg, Angelika, Majdani, Omid, Lenarz, Thomas
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 15.05.2017; Public Library of Science (PLoS)
• Subjects: Acoustic measurement; Acoustic noise; Acoustic Stimulation; Acoustics; Activation analysis; Adult; Adults; Aged; Aged, 80 and over; Amplification; Auditory discrimination; Auditory perception; Auditory Threshold; Biology and Life Sciences; Brain stem; Cochlea; Cochlear Implants; Comprehension; Data processing; Deafness; Demography; Discrimination; Ear; Ears & hearing; Electric Stimulation; Electrical stimuli; Electrodes; Electrodes, Implanted; Engineering; Etiology; Evaluation; Female; Frequency; Hearing aids; Hearing loss; Hearing Loss - therapy; Humans; Insertion; Localization; Low frequencies; Male; Medicine and Health Sciences; Microprocessors; Middle Aged; Music; Noise; Nuclei; Otitis media; Otolaryngology; Perception; Physical Sciences; Position (location); Preservation; Receiving; Retrospective Studies; Rubella; Social Sciences; Spectral resolution; Speech; Speech Perception; Speech recognition; Steering; Stimulation; Studies; Surgery; Surgical implants; Temporal bone; Time Factors; Transplants & implants; Treatment Outcome; Voice recognition; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0174900

This investigation evaluated the effect of cochlear implant (CI) electrode length on speech comprehension in quiet and noise and compare the results with those of EAS users. 91 adults with some degree of residual hearing were implanted with a FLEX20, FLEX24, or FLEX28 electrode. Some subjects were postoperative electric-acoustic-stimulation (EAS) users; the other subjects were in the groups of electric stimulation-only (ES-only). Speech perception was tested in quiet and noise at 3 and 6 months of ES or EAS use. Speech comprehension results were analyzed and correlated to electrode length. While the FLEX20 ES and FLEX24 ES groups were still in their learning phase between the 3 to 6 months interval, the FLEX28 ES group was already reaching a performance plateau at the three months appointment yielding remarkably high test scores. EAS subjects using FLEX20 or FLEX24 electrodes outscored ES-only subjects with the same short electrodes on all 3 tests at each interval, reaching significance with FLEX20 ES and FLEX24 ES subjects on all 3 tests at the 3-months interval and on 2 tests at the 6- months interval. Amongst ES-only subjects at the 3- months interval, FLEX28 ES subjects significantly outscored FLEX20 ES subjects on all 3 tests and the FLEX24 ES subjects on 2 tests. At the-6 months interval, FLEX28 ES subjects still exceeded the other ES-only subjects although the difference did not reach significance. Among ES-only users, the FLEX28 ES users had the best speech comprehension scores, at the 3- months appointment and tendentially at the 6 months appointment. EAS users showed significantly better speech comprehension results compared to ES-only users with the same short electrodes.