Resonance in the Concha Cavity is Associated with the Size of the Pinna

허승덕,; 이제현,; 전성민,; 김인아,

ORIGINAL ARTICLE

Commun Sci Disord. 2010;15(1): 107-113.

허승덕^` , 이제현^` , 전성민^` , and 김인아^`

허승덕| 이제현| 전성민| 김인아

ABSTRACT

Background & Objectives
The pinna is located on the side of the head and forms the visible part of the hearing system. The cavum concha, an air-filled cone-shaped cavity deep within the ear canal, is also part of the pinna. Both of these structures collect sound and are connected to the external auditory canal (EAC). The pinna, cavum concha and EAC are not separated in the audiology field because these organs are connected anatomically and physiologically. Hearing aids play an importantroll in audiological rehabilitation. However, the use of hearing aids may cancel out the resonances of the cavum concha and EAC or may result in a gain higher than that of the electroacoustic gain. These variables differ among the different types of hearing aids. The value of the gain depends on to the microphone location effect (MLE) and the volume of the residual ear canal. The pinna and cavum concha influence the MLE. Hence, cavum concha resonance may play an important role in auditory physiology because resonance provides an important clue for direction determination. The goals of this study are to measure normative data in Korean adults and todetermine whether the size of the pinna influences the concha resonance.
Methods
Eighteen healthy-young-adults (36 ears, M:F=5:13) participated in the present study. The resonance of the concha cavity was evaluated at azimuth 0° and azimuth 45°, and the relationship between the size of the pinna and the resonance of the concha cavity were analyzed statistically.
Results
The mean height of the pinna was 52.8 to 73.8 (61.7±5.5) ㎜, the mean width of the pinna was 16.35 to 29.9 (12.2±2.9) ㎜, and the mean area of the pinna was 458.62 to 1034.54 (706.21±165.58) ㎟. The maximum resonance frequency was 4 ㎑ in both directions. The maximum resonance gains were 12.2 (±2.9) ㏈ at azimuth 0° and 13.6 (±3.5) ㏈ at azimuth 45°. The mean lengthof the concha cavity was 61.7 (±5.5), and its mean width was 22.4 (±3.3) ㎜. The sizes of the pinna and concha cavity were significantly correlated (p=0.01). However, there was not statistical significance between the size of pinna and the resonance of the concha avity.
Discussion & Conclusion
The results of this study suggest that pinna size does not affect the resonance of the concha cavity.