Non human formant frequencies

Question

Some animals are specially trained to repeat human phrases, others just make sounds that people interpret as speech.

In this video a rooster seems to say "Cristo Viene" (Christ is coming).

Taking the spectrogram of that rooster to analyze the formant position of the vowels I can't find any matches (I was using a formant position UCLA's chart from here ), because the pitch of the animal is obviously different to formant position of human male or females.

Does anybody knows the way to find the formants position at different pitches? (I put the spectrogram of the rooster above)

Answer 1

I think you have a misunderstanding about formants, pitch and partial tones. The spectrogram shows the position of the partials and you can also estimate their fundamental frequency, or pitch, trajectory to be the position of the lowest partial. The formant structure is not readily recognizable from this representation.

Formants are the resonances of the vocal tract but these resonance frequencies are not necessarily excited because they don't coincide with the partial frequencies that are at integer multiple positions of the fundamental frequency. Rather, the formants shape the amplitude of the exciting signal, in this case best described by the partials. You can think of the formants as the peaks of the (smooth) envelope that you can draw on a frequency-amplitude diagram showing the amplitudes of the partials.