Just words

German Hunting Cap

When I got into this line of work (marine conservation), I didn’t know it was going to require so much traveling. And while we do generate a lot of products out of our humble office, we “feed the pony” by attending conferences and workshops, and “polishing the marble floors” in Washington, DC.

All of this air travel is a climate nightmare, but the conferences allow for the general momentum of the field to advance within the community of the players; academics, research scientists, regulators, and military and industrial stakeholders.

While I’ve been attending these affairs for some 20 plus years, I’ve always been at a bit of a disadvantage – given the circuitous path that landed me in the field. Most participants at these events attended school together under the same collection of professors, and have been funded by the same agencies, so I’ve been largely out of the fabric of at least the academic momentum. And I’ve been only included in the industrial and Navy circles due to the hospitality of certain individuals.

But after 20 years of seeing a lot of the same folks, and greeting a lot of the newcomers, I’ve probably become somewhat of an installation, pushing my peculiar ideas into the field.

Finally, after more than a decade, two of these ideas ended up on the big screen at the recent Aquatic Noise conference. There was a whole session on “Kurtosis” – which is just a statistical term for “set variability.” But when the set is of sound amplitudes and frequencies, there is a direct correlation between high kurtosis and a nasty sound quality. So given this connection, kurtosis should figure into noise exposure impacts – a point I’ve argued for years.  (An entire conference session on this term was a bit of a vindication.)

A second term I’ve been flogging is “soundscape” which was spread across a number of sessions, inferring a more systematic evaluation of sounds in context.

The term was coined in the mid 1970s by acoustic ecologist R. Murray Schafer and loosely used since then to infer a sense of acoustical environment or habitat. Recently the International Standards Organization (ISO) etched a pretty detailed definition of the word in the context of human sound perception; but it hinges on human expressions of their subjective perception. This would be hard to define in animal bioacoustics, if for no other reason than we can’t ask a hermit crab or a beaked whale what they think about the acoustical habitat within which they reside. (And to paraphrase Ludwig Wittgenstein, even if they could tell us, we wouldn’t understand what they were talking about.)

I believe the term is important in biological settings because at present animal exposures to anthropogenic noise is regulated solely in terms of how loud the noise is, without any consideration of context. This is akin to declaring that John Phillip Sousa Marching Bands are OK for humans, without indicating that they don’t work so well in libraries or churches.

Looking at acoustical habitats through the lens of soundscapes also opens up the larger inquiry of how a habitat changes in response to changing conditions, such as climate change, or industrialization. Given that the health and density of sound-making animals is easier to hear than to visually count, long-term recordings can give us a read on the evolving health of natural habitats.

So the inclusion of these terms points to a more systematic consideration of aquatic noise impacts, and allowed me to put a couple of little feathers in my cap.

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