How to write a wah-wah sound effect in C++?

I'm trying to learn to write a wah-wah sound effect. Just for fun really :)

So far, I've done a lot of research, and this page explains it the best. http://www.geofex.com/Article_Folders/wahpedl/voicewah.htm

Basically, I'm just looking for any simple C++ examples to generate a Wah-wah (ooaaooaa) effect.

Eventually once this is done, I hope to be able to also create a "eeeoooeeeoo" effect, or a "eeaaeeaa" effect :) Sort of vowel sythnthesis, but for music.

If I find any good examples I'll link to them here.

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I'm having trouble with the mathematical side of things.

What waves do I need to generate to make an "E" sound? What waves do I need to generate to make a "O" sound?

I did try making two frequencies, with harmonics, according to that page, and adjusting the two frequencies, but it still sounded like electronic beeps, not vowels.

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http://www.acoustics.hut.fi/publications/files/theses/lemmetty_mst/chap3.html This seems good. There are some numbers I can use. Hopefully it will sound "vowelish".

EDIT: I tried making some sounds at those frequencies mentioned on the page (100hz,600hz,1000hz,2500hz). It did not sound "vowelish". Maybe very slightly, but not properly.

So obviously I need to do more frequencies to make a proper "a" sound. Although I'm not sure WHAT frequencies.

I COULD just record my own voice. And then maybe download some otherpeople speaking vowels. And then find a spectrum analyser app. But I tried searching for a spectrum analyser app, and the first one I found wouldn't work on sound files just microphone input. Seems like it will be a lot more work trying to fi开发者_运维问答nd a spectrum analyser app that does what I need. I might need to write my own.

Shame I can't find a resource with a list of requencies to generate a certain vowel from... just so I can LEARN from this. And then using that knowledge, develop a "vowel filter" that works like a wahwah but with "ioio" or "eaea" sounds.

Right now, the amount of effort I need to do:

• download good vowels
• test perhaps 4 apps to see if it can analyse frequency spectrums from a file
• generate the frequencies from that spectrum
• test the frequencies to see if it sounds "vowel-like"

Its not really "fun" anymore. Its work. Shame. As I have other (real) work to be doing. I'll park this one until I find enough answers that will make this project fun to work on.

About sounding like vowel, you should look at the Formants. They help very much in synthesizing voice.

Passing your sound thru a Formant filter may lead precisely to the effect you want.

EDIT: I insist a Formant filter IS NOT a wah-wah effect. A Wah-wah effect is only a simple bandpass filter. A formant filter is more complex.