Human hearing beats FFT Options

[ncdrawl]

http://phys.org/news/2013-02-human-fourier...-principle.html

[2Bdecided]

By taking an FFT, you are performing an (approximate, with issues) time/frequency analysis. You can picture is as a time/frequency grid. Click on "spectral view" in your favourite audio editor, and there it is (but only the amplitude is visible; FFT phase is vital too).

If you use a short FFT, you have fine time resolution, but wide frequency bins.
If you use a longer FFT, you have fine frequency resolution, but longer time bins.

e.g. sampling at 44.1kHz:
a 64-point FFT gives you blocks 1.5ms apart, and 689Hz apart.
a 1024-point FFT gives you blocks 23ms apart, and 43Hz apart.
a 65536-point FFT gives you blocks 1.5 seconds apart, and 0.7Hz apart.

The analysis limit claimed for FFT in that paper (and derived right at the start), is 4*pi better than just hitting the nearest block in this spectral grid would give you.

The human auditory system is doing 10x better than this.

The human auditory system is stunningly good at picking out the start of sharp-onset notes - it amplifies the onset greatly.
IIRC the human auditory system doesn't use the (fairly poor) frequency resolution of its filterbank to determine pitch. There are a couple of different models of how pitch perception probably works, but counting cycles and/or tracking harmonics are the simplest (not entirely accurate) ones. They barely need the filter bank at all.

I'm hoping someone will explain this better though.

Cheers,
David.