Original SynthesizedThe SYNTH program provides graphical control of the time-varying formant frequencies (F1-F5), fundamental frequency (F0), overall amplitude (AV), and formant bandwidths (B1-B5). The graphical display consists of three figure windows. The main window panel displays the frequencies of the formants (F1-F5) as a function of time. On the right side of the panel there are several labeled pushbuttons that control track selection, synthesis, playback, display reset, and program termination.
Tracks can be modified using one of two drawing modes. Coordinate values can be set individually (point-draw mode) or a group of frames can be assigned values by linear interpolation between two specified endpoints (line-draw mode). To use the point-draw mode, the cursor (by default, a small cross) is positioned at the desired location and the left mouse button is pressed. To use line-draw mode, the cursor is positioned at one of the desired endpoints of the line segment and the right button is pressed. The cursor is then re-positioned at the other endpoint and the right button is pressed a second time. Each time a change is made using either point-draw or line-draw modes, the track is re-plotted to provide immediate feedback for the user. Track modification is terminated by pressing the middle button on a 3-button mouse (or by pressing the escape key, if using a 2-button mouse).