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Is cartilage conduction classified into air or bone conduction?
Author(s) -
Nishimura Tadashi,
Hosoi Hiroshi,
Saito Osamu,
Miyamae Ryosuke,
Shimokura Ryota,
Matsui Toshie,
Yamanaka Toshiaki,
Levitt Harry
Publication year - 2014
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1002/lary.24485
Subject(s) - thermal conduction , bone conduction , cartilage , medicine , materials science , anatomy , composite material , audiology
Objectives/Hypothesis The aim of this study was to establish the sound transmission characteristics of cartilage conduction proposed by Hosoi (2004), which is available by a vibration signal delivered to the aural cartilage from a transducer. Study Design Experimental study. Method Eight volunteers with normal hearing participated. Thresholds at frequencies of 0.5, 1, 2, and 4 kHz for air conduction, bone, and cartilage conductions were measured with and without an earplug. The sound pressure levels on the eardrum at the threshold estimated with a Head and Torso Simulator were compared between air and cartilage conductions. The force levels calibrated with an artificial mastoid at the threshold were compared between bone and cartilage conductions. Results The difference in the estimated sound pressure levels on the eardrum at the thresholds between air and cartilage conductions were within 10 dB. In contrast, the force levels at the thresholds for cartilage conduction were remarkably lower than those for bone conduction. These findings suggested that sounds were probably transmitted via the eardrum for cartilage conduction. The threshold shifts by an earplug showed no significant difference between bone and cartilage conductions at 0.5 kHz. At 1 and 2 kHz, the threshold‐shifts increased significantly in the order of bone, cartilage, and air conductions. These results suggested that airborne sound induced by the vibration of the cartilaginous portion of the ear canal played a significant role in sound transmission for cartilage conduction. Conclusions Cartilage conduction has different characteristics from conventional air and bone conductions. Level of Evidence N/A. Laryngoscope , 124:1214–1219, 2014