Hearing preservation in cochlear implantation for electric acoustic stimulation

Acta Otolaryngol. 2004 May;124(4):348-52. doi: 10.1080/00016480410016432.

Abstract

Objective: To evaluate the possibility of preservation of low-frequency hearing in atraumatic cochlear implant electrode insertion procedures for combined, ipsilateral electric and acoustic stimulation.

Material and methods: A total of 21 patients were implanted with a MED EL C40+ cochlear implant using an atraumatic electrode insertion technique to preserve residual low-frequency hearing. Pure-tone audiometric thresholds were measured pre- and postoperatively to evaluate the degree of preserved hearing. Speech discrimination tests in quiet and with background noise were performed in a patient with successful hearing preservation.

Results: Using the atraumatic electrode insertion procedure with an insertion depth of 360 degrees (18-24 mm), hearing preservation could be achieved in 18/21 patients (85.7%). Three patients (14.3%) lost their residual low-frequency hearing after the implantation. Residual hearing was preserved completely in 13 patients (61.9%) and partial hearing preservation was possible in 5 (23.8%). Preliminary speech discrimination tests showed a dramatic benefit for the combined electric and acoustic stimulation mode compared to cochlear implantation alone.

Conclusion: Preservation of low-frequency hearing in cochlear implantation is possible in patients implanted because of profound high-frequency deafness. With the development of new, more atraumatic electrode designs, preservation of residual hearing should be further improved.

MeSH terms

  • Acoustic Stimulation
  • Adolescent
  • Adult
  • Aged
  • Audiometry, Pure-Tone
  • Child, Preschool
  • Cochlear Implantation*
  • Electric Stimulation
  • Female
  • Hearing Loss, High-Frequency / physiopathology
  • Hearing Loss, High-Frequency / surgery*
  • Hearing*
  • Humans
  • Male
  • Middle Aged
  • Speech Perception