XVocal Menu

I. Getting Started on XVocal

In order to run the program, you have to set the path in your .cshrc file as follows:
setenv LD_LIBRARY_PATH /usr/local/X11R5/motif/lib:$LD_LIBRARY_PATH

II. Run the program

Run the executable file xvocal.
(For better color, you may try xvocal -background white)

III. Main Menu

1. VT Calculation
   Provides a choice of five different vocal tract models for calculation.
   
   
2. Configuration
   Change the physical configuration of the vocal tract.
   
   
3. Physical Constants
   Modify the physical constants in simulation
   
   
4. Save Option
   Modify the save options
   
   
5. Quit
   Quit the program
   
   
6. Help
   Help menu

IV. VT Calculation Menu

1. Uniform tube model
   Area function is specified by the uniform cross-sectional area, the tube length and the number of sections.
   
   
2. 2 Tube model
   Area function is specified by
   1. Cross-sectional area of the 1st section
   2. Length of the 1st section
   3. Area of the 2nd section
   4. Length of the 2nd section
   
   
3. 3 Parameter model
   Area function is specified by Fant's 4 tube model with 3 parameters:
   1. Location of the tongue-body center
   2. Cross-sectional area of the tongue-body section
   3. Mouth-opening area
   (Note in the original model that the 3rd parameter is the length over area ratio. But we assume, here, the lip tube length is fixed to 1cm. Ref: Cunnar Fant (1960). Acoustic Theory of Speech Production, Mouton, The Hague, p. 74)
   
   
4. Linear Articulatory model
   Area function is specified by parameters
   
   
5. From file
   Area function is read from file in specific format.
   The data files, with extension .are, are in ASCII in the following format
   

   [filename]
   no. of sections
   length of a section
   cross-sectional areas of each section (from glottis to mouth) separated by
   comma.
   

   Sample files can be found in AREA directory.

1. Calculate
   Compute the frequency spectrum and the formant frequencies.
   
   
2. Synthesis
   Synthesize a stationary vowel with the current area function. The duration is about 300ms, and a predefined rise-fall F0 pattern is used. The vowel signal and glottal signal is stored in temporary files. To transfer onto a permanent file, select menu "save".
   
   
3. Keep (Save)
   Save the current tract calculation conditions in a text file. The file name consists of the save_file_code followed by the current value of the file_count. The catalogue code is .DOC for area function and .SIG for synthesized signal.

V. Configuration Menu

1. Radiation boundary: RL-circuit of short circuit, at the lip or nostril opening.
   When toggle button is on, there is radiation and set to RL-circuit.
   
   
2. Wall characteristics: Yielding or rigid
   When toggle button is on, there is wall yielding.
   
   
3. Nasal tract: On or Off
   When toggle button is on, nasal tract is on. Nasal coupling is further specified when you choose a model from VT Calculation menu again.
   
   
4. Glottis: Open or Close
   When toggle button is on, glottis is open.
   (At this moment, spectrum is assumed to be empty when the glottis is open )

VI. Physical Constant Menu

VII. Save Option Menu

Filename consists of a fixed code followed by an integer, which is incremented every time a save file is created. The fixed code can be changed by choosing the Save file code item. With the new code, the counter is zeroed.

1. The Save directory option changes the directory of the synthesized file to be saved. Default is /SIG/.
   
   
2. temp_sig_path and temp_glt_path are the temporary file names for synthesis of stationary vowels.
   
   
3. The Area directory option changes the directory of the area function files. Default is /AREA/.

VIII. Vowel Playback

To playback the synthesized vowel(see IV. VT Calculation Menu 2. Synthesis), you have to exit XVocal. Then change to SIG directory. The .sig files are the binary files of the vowel. You may convert it to any format for any audio players.

Some Matlab programs were developed by Edmond Chui to play it back in Matlab and convert the binary file to .au format. You may try one of the following:

1. To play the signal in matlab, first use the function convert to downsample the 10 kHz signal from XVocal to 8 kHz. Then, use the sound function to play it back. The syntax is as follows:
   >> y = convert(filename); % filename must be in single quotes % and with extension .SIG >> sound(y, 8000); % must be 8000 for the sampling rate
2. To convert the signal to .au format and play it outside matlab, do the following: >> play(in_file, out_file); % in_file must be .SIG and % out_file must be .au