Re: xeno-canto developments

["Dan Dugan" dandugan_1999]

> And example I've recently come across is Little Button-quail (I think). T=
hey're around 400Hz, so hard to see at the bottom of the image if the scale=
 goes up to 15kHz, and the call is long and slow. If the horizontal scale i=
s too stretched out they appear on the spectrogram almost as a horizontal l=
ine, but if a more compressed scale is used (about a minute per screen widt=
h) then they become very obvious little horse-shoe shapes.

The XC example used a linear frequency scale on the vertical axis. This is =
great for high-frequency insects and birds but compresses lower frequencies=
 to the point of invisibility. It's kind of a left-over from early spectrog=
ram technology, but academic people are used to it and consider it to be th=
e the standard method. A spectrogram with a dB (log) vertical axis shows th=
e full range in proportion.

-Dan