Whales hear through their jaws, right? Maybe not, if a new study is correct...
Researchers from San Diego State University and the University of California have been using computer models to mimic the effects of underwater noise on an unusual whale species and have discovered a new pathway for sound entering the head and ears.
Since 1968, it has been believed that noise vibrations travel through the thin bony walls of toothed whales' lower jaw and onto the fat body attached to the ear complex. This research shows however that the thin bony walls do not transmit the vibrations. In fact they enter through the throat and then pass to the bony ear complex via a unique fatty channel.
Press release here. The study by a trio of California researchers, Ted Cranford, Petr Krysl and John Hildebrand, appears in the latest issue of Bioinspiration & Biomimetics. There we find this proviso:
Finally, the results reported here must be considered with a healthy dose of skepticism because the simulations push beyond our current knowledge base for this species.
So, maybe not a revolution in cetacean acoustics after all. But still. Interesting stuff.
What is the density difference between seawater and fat, as opposed to seawater and bone, at different depths? Just wondering.