• Title/Summary/Keyword: 방어기술

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A Fundamental Study on the Auditory Characteristics of Amberjack Seriola dumerili in the Coast of Jeju Island (제주 연안산 잿방어의 청각특성에 관한 기초적 연구)

  • 서익조;김성호;김병엽;이창헌;서두옥
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.39 no.4
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    • pp.269-275
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    • 2003
  • In this paper, We examined auditory threshold and critical ratio of amberjack seriola dumerili, in the Jeju Island coastal waters, to find out hearing ability of the fish. The auditory threshold level, critical ratio and hearing index of amberjack were determinded by conditioning method using a sound coupled with electric shock in the condition of ambient noise or white noise in an experimental water tank. The audio-signals of pure tone and electric shock were from 80 HZ to 800 Hz and DC 7 V, respectively. Values for the critical ratios were calculated in terms of the masked thresholds using the noise projected to stable spectrum levels at all measurement frequencies of background noise. Masking noises were in the spectrum level range of 65 dB∼75 dB $(re 1{\mu}Pa\sqrt{Hz})$. The auditory thresholds of amberjack within the test the frequencies were most sensitive at 300HZ as 94.5 dB. The critical ratios of fishes ranged from 36.4 to 52.8 dB. The noise spectrum level that started masking was about 58∼72 dB within frequencies.