Sound transmission by cartilage conduction in ear with fibrotic aural atresia

1
Sound transmission by cartilage conduction in
ear with fibrotic aural atresia

• Chihiro Morimoto, MD Tadashi Nishimura, MD, PhD
  Hiroshi Hosoi, MD, PhD Osamu Saito Fumi
  Fukuda Ryota Shimokura, PhD Toshiaki Yamanaka,
  MD, PhD

2

• Aim
• Test proposed hearing aid using cartilage
  conduction (CC) as alternative to bone conduction
  (BC).
• Relevance
• Transducer developed for this application
• Lightweight.
• Requires much smaller fixation force than BC.
• More convenient to use.
• CC can benefit patients with fibrotic aural
  atresia.
• Fibrotic tissue connected to ossicles provides
  additional pathway for sound to reach cochlea via
  CC.

3
Method

• Measured BC and CC thresholds in 6 ears with
  fibrotic aural atresia.
• Investigated relationship between CC thresholds
  and results of computed tomography.

4
Results

• In ears with fibrotic tissue pathway
• CC thresholds were lower than BC thresholds at
  0.5 and 1.0 kHz.
• At 2.0 kHz
• No significant difference between BC and CC
  thresholds.

5
Conclusion

• Findings suggest that sound in low to middle
  frequency range is transmitted more efficiently
  by CC via fibrotic tissue pathway than BC.
• Hearing devices using CC can aid rehabilitation,
  particularly in patients with fibrotic aural
  atresia.