Formant Synthesis Demo

Very very nice this no-install application.
It shows the relation between formants and vowels, with the possibility to change pitch, source wave, shape, bandwidht.
For win, linux and mac.

From the site:

What is this?
This application demonstrates formant-based synthesis of vowels in real time, in the spirit of Gunnar Fant's Orator Verbis Electris (OVE-1) synthesizer of 1953.

How to use
Set source and filter parameters at the top. Click and drag in the "vowel space" to hear the vowels.
Right-click to select target language for vowel symbols.
LPC power spectrum of source (red) and output signal (green) are to the right, waveforms are displayed at the bottom.
The source type "sampled" will use a sound file containing a single period of a waveform as voice source.

http://www.speech.kth.se/wavesurfer/formant/