SFS/ESynth Help File
ESynth is a program designed to explain the harmonic analysis and synthesis of signals. With ESynth you can create signals by adding togather individual sinusoidal waveforms (sinewaves) and study the resulting waveform and spectrum. You can also perform an analysis of an input waveform, to see how a given sound can be represented in terms of a sum of sinewaves.
ESystem is a simple application that is complete in itself but which is also designed to be compatible with the Speech Filing System (SFS) tools for speech research.
Other menu options
On the waveform displays the left mouse button sets the position of the left (start time) cursor. The right mouse button sets the position of the right (end time) cursor. Use these to specify which area to expand in the Zoom-in command.
On the spectrum graph the mouse can be used to change the frequency, amplitude or pahse of any component. To move a component, position the mouse cursor over the little box at the top of the harmonic. The mouse cursor should change shape into a four-headed arrow. Now press and hold down the left muse button, dragging the harmonic to its new position. You can change the phase of a harmonic by positioning the cursor as before and pressing and holding the right mouse button. You should see a pop-up menu which allows you to set the phase to be 0, 90, 180 or 270 degrees. This menu also allows you to delete a harmonic.
Control panel operation
The control panel has three main areas: a list of the details of the sinewave components of the synthetic signal, edit boxes for entering frequency, amplitude and phase values, and a set of buttons for adding, deleting or changing entries, and for playing out the synthetic output signal. To change an existing component, click on the component in the list box, change the values in the edit boxes, then click on the Update button. To add a new component, enter the new values in the edit boxes and click on Add. To delete a component, select it in the list box and click on Delete.
You can show and hide the control panel using the Edit button on the toolbar.
The following keyboard shortcuts are provided:
Want to learn more?
If you find the study of speech interesting and would like to know more, why not visit the Internet Institute of Speech and Hearing at www.speechandhearing.net ? There you will find tutorials, reference material, laboratory experiments and contact details of professional organisations.
Please send suggestions for improvements and reports of program faults to SFS@phon.ucl.ac.uk.
Please note that we are unable to provide help with the use of this program.
ESynth is not public domain software, its intellectual property is owned by Mark Huckvale, University College London. However ESynth may be used and copied without charge as long as the program and help file remain unmodified and continue to carry this copyright notice. Please contact the author for other licensing arrangements. ESynth carries no warranty of any kind, you use it at your own risk.
|© 2003 Mark Huckvale University College London||Version 1.1 July 2003|