Re: Clustering around the pitch floor

Boersma Paul
 

On 7 Dec 2019, at 23:38, Austin Zheng <azaustinzheng@...> wrote:

I notice that there is a cluster of frequency estimates near the pitch floor.
The explanation is the same as the explanation of the octave cost that I answered you about before.

If you have a perfectly periodic signal with a period of 5 milliseconds, then 200 Hz is the pitch candidate that you want. However, the signal does not only repeat itself after 5 ms, but also after 10 ms, 15 ms, 20 ms, 25 ms..., so equally good pitch candidates are 100 Hz, 66.7 Hz, 50 Hz, 40 Hz...

The one that you want from all those equally good candidates, must be the highest of those frequencies; hence the octave cost parameter that I wrote about. Please look it up in the paper I wrote about this in 1993, which has all the pictures that help explain this.
_____

Paul Boersma
Professor of Phonetic Sciences, University of Amsterdam

Visiting address: Spuistraat 134, room 632, Amsterdam
Mail: P.O. Box 1642, 1000BP Amsterdam, The Netherlands
Website: http://www.fon.hum.uva.nl/paul/

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