FIGURE 1 in An overview of fish bioacoustics and the impacts of anthropogenic sounds on fishes

FIGURE 1 Fish hearing sensitivity (thresholds) obtained under open sea, free-field, conditions in response to pure tone stimuli at different frequencies. The lower the thresholds (y-axis), the more sensitive the fish is to a sound. Thus, Clupea harengus has best hearing of all of these species over a wider range of frequencies. Note that the thresholds in Gadus morhua and C. harengus obtained under quiet conditions may be below natural ambient noise levels, especially at their most sensitive frequencies. In the presence of higher levels of noise, the thresholds would be raised, a phenomenon referred to as masking. Gadus morhua and C. harengus are sensitive to both sound pressure and particle motion, whereas Limanda limanda and Salmo salar are only sensitive to particle motion. The reference level for the particle velocity is based on the level that exists in a free sound field for the given sound pressure level. n.b., For the particle velocity levels in this figure to match the sound pressure levels in a free sound field it is necessary to calculate an appropriate particle velocity reference level. If the standard reference levels are used, then the curves will not match one another and so they are not included here to keep the figure relatively simple. Fig. © 2018 Anthony D. Hawkins, all rights reserved