Repeating the Message: Evidence of Multiple Sound Sources in the Bottlenose Dolphin

A colleague of mine called me this evening to recount a disturbing incident at the Effects of Noise on Aquatic Life conference recently held in Dublin, Ireland. A high-profile researcher there apparently asserted that bottlenose dolphins (Tursiops truncatus) only have a single sound source, specifically calling out research I was part of as having been mistaken.

Now, I wasn’t there, so I am not going to name names. But I do think it is appropriate to note that the assertion that only a single sound source exists goes against the evidence.

My dissertation goes on at length about what we determined concerning bottlenose dolphins and biosonar sound production. I can relate that we did not mistake “reflections” or something similar to come to a conclusion that two sound generators exist in the bottlenose dolphin. And while I like my dissertation, the paper from 2011 that I was a co-author on comes with something that doesn’t come with a dissertation: video. Yes, we have video of two sound sources in operation in a single bottlenose dolphin.

Please, folks; we can disagree on whether multiple sound sources are either commonly or rarely or never active simultaneously. But we can’t disagree that both sets of phonic lips can and are used by bottlenose dolphins to produce sound. Among other evidence, we have the video.

If this goes on, I think that we can term this the latest form of denialism.