한국 단음절어의 주파수중요기능 연구 |
이경원1, 김진숙2 |
1한림국제대학원대학교 청각학과 2한림대학교 자연과학대학 언어청각학부 |
The Study of Frequency Importance Function of the Korean Monosyllabic Words |
Kyoung Won Lee1, Jin Sook Kim2 |
1Department of Audiology, Hallym University of Graduate Studies, Seoul, Korea 2Division of Speech Pathology & Audiology, College of Natural Science, Hallym University, Chuncheon, Korea |
Correspondence |
Jin Sook Kim ,Tel: (033) 248-4950, Fax: (033) 248-2213, Email: jskim@hallym.ac.kr
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Received: April 27, 2012; Revised: June 10, 2012 Accepted: June 11, 2012. Published online: June 30, 2012. |
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ABSTRACT |
Speech intelligibility index (SII) can be utilized for predicting speech recognition abilities of the hearing impaired based on the pure
tone thresholds. For calculation of SII, frequency importance function (FIF) has to be produced considering the language
characteristics. The purpose of this study was to derive FIF at 1/3 and 1 octave frequency bands using recently developed Korean
standard monosyllabic word lists for adults (KS-MWL-A). KS-MWL-A speech materials were presented to normal hearing 17 adults,
age ranging from 19 to 25, after filtering with 7 high pass filters (HPFs) and low pass filters (LPFs) combined with Korean speech
shaped noise. The cut-off frequencies (COFs) of the LPF were 224, 447, 891, 1413, 2239, 3548, 5623 Hz and the HPF were 447, 891,
1413, 2239, 3548, 5623 Hz. Signal-to-noise ratios (SNRs) were -10 to +8 dB by 2 dB steps. Relative speech intelligibility index
(R-SII) were derived by word recognition scores (WRSs) as a function of COFs at each SNR. Finally, FIFs were calculated by
cumulative curves as function of frequencies. Regression equation of R-SII and WRS as a function of SII showed cubic function as
y = 41.77x3-159.01x2+208.31x-4.08 (R2 = 0.992, p < .000). As Korean R-SII increased 0.0 to 0.5, WRS increased rapidly comparing
to English R-SII. Maximum FIFs of KS-MWL-A showed 0.2190 at 800 Hz by 1/3 octave band frequency and 0.4507 at 1,000 Hz by 1
octave band frequency. Crossover frequencies of KS-MWL-A showed 1,518-1,941 Hz and increased as SNR increased. All the results
were different from English monosyllabic words. The results of this study can be utilized for calculating hearing aid fitting formula,
for determining aims, and effective process of auditory training. However, further study should be performed using various speech
materials such as Korean sentence and short passages and etc. |
Key Words:
Articulation index, Cut-off frequency, Frequency importance function, Monosyllabic word, Speech intelligibility
index. |
중심단어:
단음절어, 어음명료지수, 조음지수, 절단주파수,
주파수중요기능. |
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