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Cartilage conduction is characterized by vibrations of the cartilaginous portion of the ear canal.

Nishimura T, Hosoi H, Saito O, Miyamae R, Shimokura R, Yamanaka T, Kitahara T, Levitt H - PLoS ONE (2015)

Bottom Line: When the water was additionally injected to reach the cartilaginous portion, the thresholds at 0.5 and 1 kHz dramatically decreased by 27.4 and 27.5 dB, respectively.CC generates airborne sound in the canal more efficiently than BC.The current findings suggest that CC is not a hybrid of AC and BC.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology-Head and Neck surgery, Nara Medical University, Kashihara, Japan.

ABSTRACT
Cartilage conduction (CC) is a new form of sound transmission which is induced by a transducer being placed on the aural cartilage. Although the conventional forms of sound transmission to the cochlea are classified into air or bone conduction (AC or BC), previous study demonstrates that CC is not classified into AC or BC (Laryngoscope 124: 1214-1219). Next interesting issue is whether CC is a hybrid of AC and BC. Seven volunteers with normal hearing participated in this experiment. The threshold-shifts by water injection in the ear canal were measured. AC, BC, and CC thresholds at 0.5-4 kHz were measured in the 0%-, 40%-, and 80%-water injection conditions. In addition, CC thresholds were also measured for the 20%-, 60%-, 100%-, and overflowing-water injection conditions. The contributions of the vibrations of the cartilaginous portion were evaluated by the threshold-shifts. For AC and BC, the threshold-shifts by the water injection were 22.6-53.3 dB and within 14.9 dB at the frequency of 0.5-4 kHz, respectively. For CC, when the water was filled within the bony portion, the thresholds were elevated to the same degree as AC. When the water was additionally injected to reach the cartilaginous portion, the thresholds at 0.5 and 1 kHz dramatically decreased by 27.4 and 27.5 dB, respectively. In addition, despite blocking AC by the injected water, the CC thresholds in force level were remarkably lower than those for BC. The vibration of the cartilaginous portion contributes to the sound transmission, particularly in the low frequency range. Although the airborne sound is radiated into the ear canal in both BC and CC, the mechanism underlying its generation is different between them. CC generates airborne sound in the canal more efficiently than BC. The current findings suggest that CC is not a hybrid of AC and BC.

No MeSH data available.


Related in: MedlinePlus

Threshold-shifts by the 40%- (A) and 80%- (B) water injections.Threshold-shifts from the 0%-water injection condition were described. The additional water injection from 40% to 80% of the ear canal remarkably improved the cartilage conduction thresholds at 0.5 and 1 kHz. Vertical bars indicate standard deviations.
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pone.0120135.g004: Threshold-shifts by the 40%- (A) and 80%- (B) water injections.Threshold-shifts from the 0%-water injection condition were described. The additional water injection from 40% to 80% of the ear canal remarkably improved the cartilage conduction thresholds at 0.5 and 1 kHz. Vertical bars indicate standard deviations.

Mentions: The threshold-shifts resulting from the injection of water are shown in Fig. 4A and 4B. A three–way repeated-measures ANOVA revealed statistically significant effects for mode of conduction (F [2, 12] = 524.20, p < 0.001), water volume (F [1, 6] = 52.20, p < 0.001), and frequency (F [3, 18] = 123.94, p < 0.001). All interactions among these factors were significant (p < 0.001). No significant differences in threshold-shifts at 40% water injection were found between AC and CC. In the 80%-water injection condition, the threshold-shifts for CC at 0.5 and 4 kHz corresponded to those for BC and AC, respectively. As for threshold-shifts at 1 and 2 kHz, the largest was AC, followed in order by CC and BC.


Cartilage conduction is characterized by vibrations of the cartilaginous portion of the ear canal.

Nishimura T, Hosoi H, Saito O, Miyamae R, Shimokura R, Yamanaka T, Kitahara T, Levitt H - PLoS ONE (2015)

Threshold-shifts by the 40%- (A) and 80%- (B) water injections.Threshold-shifts from the 0%-water injection condition were described. The additional water injection from 40% to 80% of the ear canal remarkably improved the cartilage conduction thresholds at 0.5 and 1 kHz. Vertical bars indicate standard deviations.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4359134&req=5

pone.0120135.g004: Threshold-shifts by the 40%- (A) and 80%- (B) water injections.Threshold-shifts from the 0%-water injection condition were described. The additional water injection from 40% to 80% of the ear canal remarkably improved the cartilage conduction thresholds at 0.5 and 1 kHz. Vertical bars indicate standard deviations.
Mentions: The threshold-shifts resulting from the injection of water are shown in Fig. 4A and 4B. A three–way repeated-measures ANOVA revealed statistically significant effects for mode of conduction (F [2, 12] = 524.20, p < 0.001), water volume (F [1, 6] = 52.20, p < 0.001), and frequency (F [3, 18] = 123.94, p < 0.001). All interactions among these factors were significant (p < 0.001). No significant differences in threshold-shifts at 40% water injection were found between AC and CC. In the 80%-water injection condition, the threshold-shifts for CC at 0.5 and 4 kHz corresponded to those for BC and AC, respectively. As for threshold-shifts at 1 and 2 kHz, the largest was AC, followed in order by CC and BC.

Bottom Line: When the water was additionally injected to reach the cartilaginous portion, the thresholds at 0.5 and 1 kHz dramatically decreased by 27.4 and 27.5 dB, respectively.CC generates airborne sound in the canal more efficiently than BC.The current findings suggest that CC is not a hybrid of AC and BC.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology-Head and Neck surgery, Nara Medical University, Kashihara, Japan.

ABSTRACT
Cartilage conduction (CC) is a new form of sound transmission which is induced by a transducer being placed on the aural cartilage. Although the conventional forms of sound transmission to the cochlea are classified into air or bone conduction (AC or BC), previous study demonstrates that CC is not classified into AC or BC (Laryngoscope 124: 1214-1219). Next interesting issue is whether CC is a hybrid of AC and BC. Seven volunteers with normal hearing participated in this experiment. The threshold-shifts by water injection in the ear canal were measured. AC, BC, and CC thresholds at 0.5-4 kHz were measured in the 0%-, 40%-, and 80%-water injection conditions. In addition, CC thresholds were also measured for the 20%-, 60%-, 100%-, and overflowing-water injection conditions. The contributions of the vibrations of the cartilaginous portion were evaluated by the threshold-shifts. For AC and BC, the threshold-shifts by the water injection were 22.6-53.3 dB and within 14.9 dB at the frequency of 0.5-4 kHz, respectively. For CC, when the water was filled within the bony portion, the thresholds were elevated to the same degree as AC. When the water was additionally injected to reach the cartilaginous portion, the thresholds at 0.5 and 1 kHz dramatically decreased by 27.4 and 27.5 dB, respectively. In addition, despite blocking AC by the injected water, the CC thresholds in force level were remarkably lower than those for BC. The vibration of the cartilaginous portion contributes to the sound transmission, particularly in the low frequency range. Although the airborne sound is radiated into the ear canal in both BC and CC, the mechanism underlying its generation is different between them. CC generates airborne sound in the canal more efficiently than BC. The current findings suggest that CC is not a hybrid of AC and BC.

No MeSH data available.


Related in: MedlinePlus