Party Problems

When our hearing is normal we can recognize our name or pick out snatches of conversation in a room where a lot of people are talking at once. If our hearing has to be digitally supplemented, this is more difficult to do.  If a computer is tasked with this “dip listening” task, it is very ineffectual. This has become known as the “cocktail party problem.”

In the current pre-print issue of the Journal of Animal Behavior, Vélèz and Bee of the U of Minnesota have pondered on the problem for grey treefrogs who have the problem of fixing up dates amid the cacophony of their numerous relatives all croaking themselves hoarse.

The problem they address is are the females able to dip listen effectively so they can pick out their soul mate calling amongst the very loud chatter of the general melee of a noisy communal bacchanal.

Well, our treefrog ladies were somewhat handicapped if their soul mates calls were done in short bursts. They seemed to lose the sound in the rise and fall of the noisy background. They did rather better if their suitors were more long winded and called out about their potential prowess in long bursts with the pulse rate of the call coming into line with the background fluctuations.

If things quieted down somewhat, the length of the calls again had to be quite long if the guys were going to get any traction. So it seems that treefrogs aren’t very good at dip listening. There again, maybe the girls just want a clearer statement of intent which doesn’t quite sound like the same old song.

  1. A. Vélèz and M. A. Bee, doi:10.1016/j.anbehav.2011.09.015

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