Fournet MEH, Silvestri M, Clark CW, Klinck H, Rice AN. Limited vocal compensation for elevated ambient noise in bearded seals: implications for an industrializing Arctic Ocean.  2021. Available at: https://royalsocietypublishing.org/doi/10.1098/rspb.2020.2712.

Fouda L, Wingfield JE, Fandel AD, ym. Dolphins simplify their vocal calls in response to increased ambient noise. Biology Letters. 2018;14(10):20180484. Available at: http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2018.0484https://syndication.highwire.org/content/doi/10.1098/rsbl.2018.0484.