This article and any supplementary material should be cited as follows: Morimoto C, Nishimura T, Hosoi H, Saito O, Fukuda F, Shimokura R, Yamanaka T. Sound

This article and any supplementary material should be cited as follows: Morimoto C, Nishimura T, Hosoi H, Saito O, Fukuda F, Shimokura R, Yamanaka T. Sound transmission by cartilage conduction in ear with fibrotic aural atresia. J Rehabil Res Dev. 2014;51(2):325–32.http://dx.doi.org/10.1682/JRRD.2013.05.0128

Slideshow ProjectDOI:10.1682/JRRD.2013.05.0128JSP

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



• 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.



Method• Measured BC and CC thresholds in 6 ears with

fibrotic aural atresia.• Investigated relationship between CC thresholds

and results of computed tomography.



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.



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.

Documents

This article and any supplementary material should be cited as follows: Morimoto C, Nishimura T, Hosoi H, Saito O, Fukuda F, Shimokura R, Yamanaka T. Sound