Wysocki Lidia Eva, Ladich Friedrich
Institute of Zoology, University of Vienna, Athanstrasse 14, 1090 Vienna, Austria.
J Assoc Res Otolaryngol. 2005 Mar;6(1):28-36. doi: 10.1007/s10162-004-4043-4.
Our current knowledge on sound detection in fishes is mainly based on data acquired under quiet laboratory conditions. However, it is important to relate auditory thresholds to background noise in order to determine the signal-detecting abilities of animals in the natural environment. We investigated the influence of two noise levels within the naturally occurring range on the auditory sensitivity of two hearing specialists (otophysines) and a hearing generalist. Audiograms of the goldfish Carassius auratus, the lined Raphael catfish Platydoras costatus and the pumpkinseed sunfish Lepomis gibbosus (hearing generalist) were determined between 200 and 4000 Hz (100-800 Hz for L. gibbosus) under laboratory conditions and under continuous white noise by recording auditory evoked potentials (AEPs). Baseline thresholds showed greatest hearing sensitivity around 500 Hz in goldfish and catfish and at 100 Hz in the sunfish. Continuous white noise of 110 dB RMS elevated the thresholds by 15-20 dB in C. auratus and by 4-22 dB in P. costatus. White noise of 130 dB RMS elevated overall hearing thresholds significantly in the otophysines by 23-44 dB. In the goldfish, threshold did not shift at 4 kHz. In contrast, auditory thresholds in the sunfish declined only at the higher noise level by 7-11 dB. Our data show that the AEP recording technique is suitable for studying masking in fishes, and that the occurrence and degree of the threshold shift (masking) depend on the hearing sensitivity of fishes, the frequency, and noise levels tested. The results indicate that acoustic communication and orientation of fishes, in particular of hearing specialists, are limited by noise regimes in their environment.
我们目前对鱼类声音检测的认识主要基于在安静实验室条件下获取的数据。然而，将听觉阈值与背景噪声联系起来对于确定动物在自然环境中的信号检测能力很重要。我们研究了自然发生范围内的两种噪声水平对两种听觉专家（骨鳔鱼类）和一种听觉通才的听觉敏感性的影响。通过记录听觉诱发电位（AEP），在实验室条件下和连续白噪声环境中，测定了金鱼Carassius auratus、条纹拉斐尔鲶鱼Platydoras costatus和南瓜籽太阳鱼Lepomis gibbosus（听觉通才）在200至4000赫兹（L. gibbosus为100至800赫兹）之间的听力图。基线阈值显示，金鱼和鲶鱼在500赫兹左右听力最敏感，太阳鱼在100赫兹时最敏感。均方根值为110分贝的连续白噪声使金鱼的阈值提高了15至20分贝，使条纹拉斐尔鲶鱼的阈值提高了4至22分贝。均方根值为130分贝的白噪声使骨鳔鱼类的总体听力阈值显著提高了23至44分贝。在金鱼中，4千赫兹时阈值没有变化。相比之下，太阳鱼的听觉阈值仅在较高噪声水平下下降了7至11分贝。我们的数据表明，AEP记录技术适用于研究鱼类的掩蔽现象，并且阈值变化（掩蔽）的发生和程度取决于鱼类的听力敏感性、频率和测试的噪声水平。结果表明，鱼类，特别是听觉专家的声学通讯和定向受到其环境中噪声状况的限制。
