변조이음향방사 억제 측정에 미치는
대측 자극 소음 강도의 영향 |
신진배1, 김지연1, 남의철2, 김진숙3 |
1한림대학교 일반대학원 언어병리청각학과 2강원대학교 의학전문대학원 이비인후과학교실 3한림대학교 자연과학대학 언어청각학부, 청각언어연구소 |
The Level Effect of Contralateral Acoustic Stimulation (CAS) on
the Distortion Product Otoacoustic Emission (DPOAE) Suppression |
Jinbae Shin1, Jiyeon Kim1, Euicheol Nam2, Jinsook Kim3 |
1Department of Speech Pathology and Audiology, Graduate School, Hallym University, Chuncheon 2Department of Otolaryngology, Kangwon National University, School of Medicine, Chuncheon 3Division of Speech Pathology and Audiology, Research Institute of Audiology and Speech Pathology, College of Natural Sciences, Hallym University, Chuncheon, Korea |
Correspondence |
Jinsook Kim ,Tel: (033) 248-2213, Fax: (033) 256-3420, Email: jskim@hallym.ac.kr
|
|
Received: June 10, 2015; Revised: July 1, 2015 Accepted: July 19, 2015. Published online: July 31, 2015. |
|
|
ABSTRACT |
As an objective and non-invasive method to evaluate functional state of medial olivo cochlear (MOC) system, there has been
growing interest in contralateral suppression of distortion product otoacoustic emission (DPOAE). Also, MOC system can be
quantified by measuring the difference DPOAE amplitude recorded in the presence of contralateral acoustic stimulation (CAS).
The purpose of this study is to identify the optimal CAS level for measuring the DPOAE contralateral suppression. In order
to do that, the effect of gender, direction of ear, and the CAS level of the DPOAE suppression for normal hearing adults
were tested. Data were collected from the thirty six ears of the eighteen subjects with normal hearing in the both ears ranged
from 21 to 26 years of age. DPOAE was tested by ILO 292 analyzer in DP-gram function. For each measurement, primary
tones frequencies were ratio f2/f1 = 1.22(f1 < f2) and intensities were L1 = 65 dB SPL, L2 = 50 dB SPL. 2f1-f2 DPOAE
was elicited using two pure tones and frequencies were measured in the range of 1,000 Hz to 6,727 Hz. Broad band noise
was used for CAS of DPOAE. CAS was delivered through a TDH 39 headphone that was placed in the participant’s
contralateral ear. CAS level was randomly presented at 50, 60, 65, 70, and 80 dB SPL. The results showed that, first, there
was no significant effect of the direction of ear for DPOAE suppression (p > .05). The results showed that the DPOAE
suppression was not significantly different between male and female (p > .05). However, the means and SDs of DPOAE
suppression for 5 different CAS levels, 50, 60, 65, 70, and 80 dB SPL, were .66(±1.20), 1.02(±1.23), 1.47(±1.73), 1.58(±1.70),
and 1.21(±1.46) dB. As the CAS levels increased, the majority of DPOAE suppression increased generally until 70 dB SPL.
Taken together, the results of this study showed that CAS at different levels induced mainly DPOAE amplitude suppression.
The amount of suppression increased as the CAS level was increased with the rolling phenomenon at 80 dB SPL than 70 dB
SPL in CAS level. Consequently, the 70 dB SPL or more level appears to generate the acoustic reflex in normal ears, and
the 70 dB SPL or less CAS level is expected to be efficient for observing decent DPOAE suppression. |
Key Words:
Acoustic reflex, Contralateral acoustic emission (CAS), Distortion product otoacousitc emission (DPOAE) suppression |
중심단어:
대측자극소음, 등골근반사,
변조이음향방사억제 |
|