[LAU] Analysis of monophonic audio signals on the commandline

[Fons Adriaensen]

On Sun, Feb 27, 2022 at 02:06:06PM +0100, Jeanette C. wrote:

> At least, analysing the song of the chaffinch is free of broadband features.
> Certainly going by ear alone. That together with some more already coded
> data from other bird calls may greatly help in a semi-analytical approach,
> which may yield good enough results.

For us humans, the gray area between time-domain and frequency domain
features is around 20 Hz. For example a 10 Hz modulation we will hear
as vibrato, but 30 Hz certainly will give a very different impression,
that of a rough sound or a complex spectrum.

Since birds are much smaller than humans, they can produce faster
modulations and they also tend to generate higher frequencies. Very
probably for them the gray zone occurs at a higher frequency.

That means that of the most revealing ways to analyse bird sounds
is to listen to them slowed down (not time-stretched). That will
allow to hear modulations that are too fast for us to be perceived
as such otherwise.

Ciao,

-- 
FA