Pitch analysis and silence vs. speech detection with SignalLab

[angelcaf]

(12-08-2012 12:16 PM)Dave Wrote:  Not sure how this is done under VC/.NET but the VU-meter could or should have a ValueChange event or a callback function. That way you can read the current value and check. If included you could try have a peek at some AudioLab demos as well.

Hello Dave, yes in .NET c# is done using the callback function to the ValueChange event.
I am starting to like more and more the library and also the wire editor! Great tool.

I have another question. I think putting the 4 lines of the algorithm that I am implementing will help understanding my question.

I need to set at TRUE a boolean flag.
So my goal is to set FLAG = TRUE upon detection of:
(1) A pause of 400ms (using vuMeter + detectLevels)
(2) preceded by at least 1000ms of speech,
(3) where the last 100ms,
(4) contain a rising or falling pitch of at least 30Hz.

I can easily do (1) even without any line of code. I am planning to do the rest similarly or adding the minimum code required.

However, what puzzles me is how to consider the previous 1000ms of speech (provided that I select "speech" in the same way as (1)).

Then, by using Fourier, how can I compute (4) just for the last 100ms?
For raising and falling I mean selecting two points (may be min and max) from the FFT output and doing the difference.

What would you suggest me to use?

Your help is really appreciated.
Thanks!