Jeroen P M Peters1,2, Edwin Bennink3, Gijsbert A van Zanten4,5. 1. Department of Otorhinolaryngology and Head and Neck Surgery, University Medical Center Utrecht, Utrecht, The Netherlands, h.p.m.peters@umcutrecht.nl. 2. UMC Utrecht Brain Center, Utrecht, The Netherlands, h.p.m.peters@umcutrecht.nl. 3. Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands. 4. Department of Otorhinolaryngology and Head and Neck Surgery, University Medical Center Utrecht, Utrecht, The Netherlands. 5. UMC Utrecht Brain Center, Utrecht, The Netherlands.
Abstract
BACKGROUND: In electric-acoustic pitch matching experiments in patients with single-sided deafness and a cochlear implant, the observed "mismatch" between perceived pitch and predicted pitch, based on the amended Greenwood frequency map, ranges from -1 to -2 octaves. It is unknown if and how this mismatch differs for perimodiolar versus lateral wall electrode arrays. OBJECTIVES: We aimed to investigate if the type of electrode array design is of influence on the electric-acoustic pitch match. METHOD: Fourteen patients (n = 8 with CI422 + lateral wall electrode array, n = 6 with CI512 + perimodiolar electrode array; Cochlear Ltd.) compared the pitch of acoustic stimuli to the pitch of electric stimuli at two test sessions (average interval 4.3 months). We plotted these "pitch matches" per electrode contact against insertion angle, calculated from high-resolution computed tomography scans. The difference between these pitch matches and two references (the spiral ganglion map and the default frequency allocation by Cochlear Ltd.) was defined as "mismatch." RESULTS: We found average mismatches of -2.2 octaves for the CI422 group and -1.3 octaves for the CI512 group. For any given electrode contact, the mismatch was smaller for the CI512 electrode array than for the CI422 electrode array. For all electrode contacts together, there was a significant difference between the mismatches of the two groups (p < 0.05). Results remained stable over time, with no significant difference between the two test sessions considering all electrode contacts. Neither group showed a significant correlation between the mismatch and phoneme recognition scores. CONCLUSION: The pitch mismatch was smaller for the perimodiolar electrode array than for the lateral wall electrode array.
BACKGROUND: In electric-acoustic pitch matching experiments in patients with single-sided deafness and a cochlear implant, the observed "mismatch" between perceived pitch and predicted pitch, based on the amended Greenwood frequency map, ranges from -1 to -2 octaves. It is unknown if and how this mismatch differs for perimodiolar versus lateral wall electrode arrays. OBJECTIVES: We aimed to investigate if the type of electrode array design is of influence on the electric-acoustic pitch match. METHOD: Fourteen patients (n = 8 with CI422 + lateral wall electrode array, n = 6 with CI512 + perimodiolar electrode array; Cochlear Ltd.) compared the pitch of acoustic stimuli to the pitch of electric stimuli at two test sessions (average interval 4.3 months). We plotted these "pitch matches" per electrode contact against insertion angle, calculated from high-resolution computed tomography scans. The difference between these pitch matches and two references (the spiral ganglion map and the default frequency allocation by Cochlear Ltd.) was defined as "mismatch." RESULTS: We found average mismatches of -2.2 octaves for the CI422 group and -1.3 octaves for the CI512 group. For any given electrode contact, the mismatch was smaller for the CI512 electrode array than for the CI422 electrode array. For all electrode contacts together, there was a significant difference between the mismatches of the two groups (p < 0.05). Results remained stable over time, with no significant difference between the two test sessions considering all electrode contacts. Neither group showed a significant correlation between the mismatch and phoneme recognition scores. CONCLUSION: The pitch mismatch was smaller for the perimodiolar electrode array than for the lateral wall electrode array.
Authors: Mario A Svirsky; Nicole Hope Capach; Jonathan D Neukam; Mahan Azadpour; Elad Sagi; Ariel Edward Hight; E Katelyn Glassman; Annette Lavender; Keena P Seward; Margaret K Miller; Nai Ding; Chin-Tuan Tan; Matthew B Fitzgerald Journal: Otol Neurotol Date: 2021-12-01 Impact factor: 2.311