Institute of Ecology and Evolution of the Russian Academy of Sciences, 33 Leninsky prospect, Moscow 119071, Russia.
J Acoust Soc Am. 2018 May;143(5):3146. doi: 10.1121/1.5039616.
The resolution of spectral patterns in adaptation background noise was investigated in a beluga whale, Delphinapterus leucas, using the evoked-potential technique. The resolution of spectral patterns was investigated using rippled-spectrum test stimuli of various levels and ripple densities and recording the rhythmic evoked responses (the rate following response, RFR) to ripple phase reversals. In baseline (no adaptation background noise) experiments, the highest RFR magnitude was observed at signal sound pressure levels (SPLs) of 100-110 dB re 1 μPa; at SPLs both below the optimum (down to 80 dB re 1 μPa) and above the optimum (up to 140 dB re 1 μPa), the RFR magnitude decreased. For high signal levels (above 110 dB re 1 μPa), low-level adaptation background noise (from -10 to -20 dB re signal level) increased RFR magnitude compared to baseline. This effect is considered to be a result of the optimization of the sensation level of the high-SPL signals due to decreasing hearing sensitivity caused by the adaptation background noise.
利用诱发反应技术研究了白鲸（Delphinapterus leucas）在适应背景噪声下的光谱模式分辨率。使用各种水平和波纹密度的波纹频谱测试刺激，并记录对波纹相位反转的节奏诱发反应（跟随反应，RFR），从而研究了光谱模式的分辨率。在基线（无适应背景噪声）实验中，在信号声压级（SPL）为 100-110 dB 时观察到最高的 RFR 幅度（相对于 1 μPa 的 1 微帕）；在低于最佳水平（低至 80 dB 相对于 1 μPa）和高于最佳水平（高达 140 dB 相对于 1 μPa）时，RFR 幅度减小。对于高信号水平（高于 110 dB 相对于 1 μPa），与基线相比，低水平的适应背景噪声（相对于信号水平的-10 到-20 dB）增加了 RFR 幅度。这种效应被认为是由于适应背景噪声引起的听力灵敏度降低导致高 SPL 信号的感觉水平优化的结果。
