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本工作在6名受试者身上比较了在有及无连续背景声作用下声音信号感受阈的变化。当信号及背景声为频率相同的纯音时,弱背景声(强度为阈上0—5分贝)能使信号感受阈降低8分贝左右。在有白噪声干扰的条件下,这一作用仍然存在。信号感受阈的降低是弱背景声提高了听觉系统对信号感受能力的结果。当背景声与信号有较大的频率差时,弱背景声即无降低信号感受阈的作用。 相似文献
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本文报导了记录人在说话时舌的运动、唇的运动、从口及鼻孔冲出的气流、以及语音的声学参数等的几种方法,并介绍了把这几种记录所得的结果进行综合加工、并提取语音信息的电子学装置.舌运动的记录方法 在说话者口腔内装一塑料人工上腭.人工上腭朝口腔的一面上装有多对电极,当舌头与上腭某些部位接触时,相应的一对或多对电极就被接通电流,把信号输至记录仪上,根据哪几对电极被接通即可判断舌在某一瞬间的位置.电极为金属片,镶在人工上腭口腔面上,以银质为最好.人工上腭的厚度一般为1.5—2毫米,电极的厚度为1毫米,电极的表面与人工上腭的表面平.各电极的导线为直径0.1毫米的漆包线,集成一股后沿人工上腭边缘引至口腔外.电极上所通的电流为300—500毫伏,2000赫,用这样的电流能得到较清楚的记录,而受试者又没有不舒服的感觉. 相似文献
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Averaged FM-evoked responses were recorded from different points on the surface of the AI areain cats and response thresholds(△F_m)for different carrier frequencies(F)were determined.△F_m variedgreatly with Fand with the site of recording.The majority of the △F_m-versus-F curves were markedwith the presence of one or more deep valleys.High,middle and low characteristic-F points of FM-responses intermingled in the AI area,a distribution entirely different from the tonotopic mapping ofthe auditory cortex in tuning responses.This was discussed in view of fine neuro-structural differentia-tion at the cortex level for auditory perception and discrimination.The smallest △F_m obtained incats with the FM-response method was lower than 1%F for F>1000Hz and lower than 10Hz forF<1000Hz. 相似文献
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本工作用两种方法研究了声音的响度辨别阈(△I/I)与信号时程(t)的关系.用信号比较法测得的△I/I不受t的长短的影响,即△I/I=K.用拍感受法测得的结果却有所不同:当t短于极限时间T时,△I/I与t的平方根成反比,即△I/I=K'(T/t)~(1/2);当t长于T时,△I/I趋于恒定,即△I/I=K';T约为150毫秒.用拍感受法测得的响度辨别阈与信号时程的关系,和以前测得的音调辨别阈与信号时程的关系十分相象. 相似文献
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A safety criterion for pressure waves incident from the front was worked out on the bases ofnumerous animal experiments and ample verification in practical exposure cases in maneuvers withvarious weapons.The proposed safety criterion is expressed as p=177-6 long T.N,where p is thepeak pressure in dB re 2×10~(-5)Pa,T——impulse duration in ms,and N——number of roundson one exposure day.This safety criterion has been proved efficient in protecting 90% or moreof the exposed personnel from pressure wave injury.For normal incidence on the ear,p shouldbe decreased by 5 dB. 相似文献
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