講演抄録/キーワード |
講演名 |
2006-08-09 14:00
同時・非同時ノッチ雑音マスキングを利用した聴覚フィルタの同調特性の推定 ○鵜木祐史・宮内良太・Chin-Tuan Tan(北陸先端大) |
抄録 |
(和) |
本稿では,周波数選択性が抑圧の影響をどれだけ受けるかを系統的に調べるため
に,同時・非同時(順向性)ノッチ雑音マスキング実験で得られた閾値データか
ら聴覚フィルタの同調特性の推定を試みる.両実験では,マスカー内,あるいは
マスカーの後に続く短時間プローブ音(10 ms)に対するマスキング閾値が,
信号周波数(0.5, 1, 2, 4 kHz),信号レベル(10, 20, 30 dB SL),信号の時間配置(同時,あるいは$0$ or $5$ msの遅延),ノッチのスペクトル配置(対称/非対称)の条件に渡って測定された.これらのデータに対し,並列型roex聴覚フィルタを適合し,同調特性としてフィルタのQ値を求めた.その結果,同調特性は,同時マスキングよりも順向性マスキングの場合に鋭くなり,信号の時間遅延が増加するにつれ鋭くなった.また,順向性マスキングの場合,信号周波数の増加に伴い同調特性は鋭くなった.同時・非同時(順向性)マスキングでの同調特性の違いは,高い周波数で大きく,低い周波数で小さくなった.この同調特性の違いは,信号周波数より低いマスカーの残余成分による抑圧の影響と考えられる. |
(英) |
This study attempts to estimate the tuning of an auditory filter, through both simultaneous and forward masking experiments with a notched-noise masker, to investigate how the effects of suppression affect estimates of frequency selectivity. In these experiments, masked thresholds of the 10-ms short probe signal centered in the masker or delayed from the masker were measured for normal-hearing subjects as a function of the signal frequency (0.5, 1.0, 2.0, and 4.0 kHz), signal level (10, 20, and 30 dB SL), signal delay, and notch-width
conditions in the nothced-noise masker. Parallel roex auditory filter was fitted to these data to derive the filter shape. Filter-Q related to
ERBs were calculated from the derived filters to compare the cochlear tuning. The estimated tunings from the forward masking data were considerably sharper than those estimated from the simultaneous masking
data. Moreover, the estimated tunings became much sharper as the center
frequency was increased. The difference between the tunings at lower frequencies with either form of masking tended to be smaler than that at
higher frequencies. The tuning may be affected by residual effects of
suppression due to lower masker components below the signal frequency. |
キーワード |
(和) |
周波数選択性 / ノッチ雑音マスキング / 聴覚フィルタ / 同調 / 抑圧 / / / |
(英) |
frequency selectivity / notched-noise masking / auditory filter / tuning / suppression / / / |
文献情報 |
信学技報, vol. 106, no. 204, EA2006-38, pp. 23-28, 2006年8月. |
資料番号 |
EA2006-38 |
発行日 |
2006-08-02 (EA) |
ISSN |
Print edition: ISSN 0913-5685 |
PDFダウンロード |
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