Breaking the Bird Barrier: Scientist Decodes Zebra Finch Language

So, there are few things to know before and see what we're trying to prove. main thing: Categorical perception: (in short) brain perceive similar sounding sounds (say A and B) in a continuous manner, and in the continuum of two sound, there would be a point where one sound (A) will switch and sound like the other sound (B).

In zebra finches, let's take an example: distance call and tet call. Both these calls are contact calls, birds use them to keep in contact with other birds. Now, we need to extract the acoustic similarity between these two calls, and test birds in a experiment where we ask them to discriminate between these two call types (and get a learning curve; say trials vs probability of correct choice). Then, we can fit a theoretical model of categorical perception to see how well they fit both in acoustic and perceptual dimensions.

This is for one function (contact call), we can do this within other call types and between other call types. At the end, we can see how much of birds' performance is explained by acoustic dissimilarity, function of acoustic calls etc.

This is what the authors have done. They first performed LDA based classification on call type to obtain distance between call types, misclassification etc. (acoustic dimension). Birds went through a series of discrimination experiments based on call types (similar to what wrote above). Then, they compared/matched acoustic and perceptual dimension.

In this research field, we often perform this types of experiments (not this exact one). So, this is not that surprising to some of us. Birds also prioritize duration a lot when telling apart calls.