Speech Articulation Training—PART 1

VATA (Vowel Articulation Training Aid)

VATA is a speech therapy tool designed to supplement insufficient or missing auditory feedback for hearing impaired persons. The system provides a visual speech display (VSD) which gives real-time onscreen feedback to a user about the quality of pronunciation of ten American-English vowel phonemes. Such feedback has been shown to be useful in speech training work with hearing impaired children. While the system is intended primarily as a speech therapy tool, it can be used in any situation where feedback about monophthong vowel pronunciation is desirable, such as in foreign language training. Requirements Hardware: 1. A PC with at least a 1 GHz processor, at least 512 Mbytes of memory and a working sound card. The program requires less than 1 Mbyte of free disk space. 2. Any computer compatible microphone. We recommend a noise canceling head mounted microphone such as the Altec Lansing AHS212. You can test the microphone and sound card using the windows Sound Recorder Program (windows/accessories/entertainment/sound recorder). You should be able to record a short sentence, and play it back with good sound quality. Software: Windows 98, windows 2000, Windows NT, or any version of windows XP Installation 1. Download the installation file (VATACPP.MSI) from the website http://www.ece.odu.edu/~zahorian/visual_speech_display.htm. You may place VATACPP.MSI in any folder, but it is recommended that you place the file in C:\Program Files\VATACPP. If this folder does not exist, you can create it with standard windows commands. 2. Beginning with My computer, locate the downloaded file from step 1. Double click on VATACPP.MSI. The program will install automatically, and create a shortcut (with an icon) on your desktop, as shown.

http://www.ece.odu.edu/~zahorian/visual_speech_display.htm

Usage

1. On the desktop double click on the VATA icon: or go to C:Program files\VATACPP\VATACPP.EXE, and run the executable file. 2. After you have clicked on the icon above, the following screen should appear:

3. VATA is a windows compatible program. There are several menu options on the top ruler bar. A summary of these is given below, looking left to right across the toolbar: GENERAL SETTINGS:

Start Processing: Clicking on this icon with a mouse, or hitting the space bar, starts the operation of VATA. Note that VATA has been configured to immediately start when the VATA program is selected from the desktop.

Stop Processing: Clicking on this icon with a mouse, or hitting escape, will stop the processing of VATA.

M—Select Adult male speaker type by clicking on this button F—Select Adult female speaker type by clicking on this button C—Select Child (typically under the age of 13) by clicking on this button G—Select General speaker by clicking on this button Selection of the speaker group, “CHILD”, “MALE” and “FEMALE,” to match the actual speaker usually provides better classification of vowel sounds. However, sometime better performance is obtained using the General speaker category. Note that only 1 of the above 4 buttons can be activated at any one time. SIGNAL PROCESSING DISPLAYS Several display modes show in real time different points in the signal processing chain and are useful for system diagnostic testing and signal analysis. These other displays include the unprocessed acoustic time signal from the sound card, the filtered time signal, the signal's frequency spectrum, and the DCT coefficients (features) of the signal.

Time waveform 1—The original acoustic waveform Time Waveform 2—The acoustic waveform after high frequency pre-emphasis Time Waveform 3—The acoustic waveform used for endpoint detection Frequency spectrum—The partially smoothed FFT log spectrum Features—The spectral features used for vowel classification

SPEECH TRAINING DISPLAYS

Bargraph The bar graph display gives feedback about how well speech utterances fit into the vowel categories (“ah” as in hot, “ee” as in beet, “ue” as in blue, “ae” as in bat, “ur” as in bird, “ih” as in bit, “eh” as in head, “aw” as in jaw, “uh” as in but, “oo” as in book ) . The bar graph display resembles a histogram, with one bar for each vowel sound. The height of the vowel's bar varies in proportion to the accuracy of the speaker's pronunciation of that vowel. Correct pronunciation yields one steady, clearly defined bar, while the remaining bars are zero or small values. For example, the display below was obtained from a male speaker producing a sustained “ur” sound.

Ellipse The “ellipse” display provides continuously variable feedback about vowel utterances The ellipse display divides the screen into several elliptical regions. Correct pronunciation of a particular sound places a basketball icon within the corresponding ellipse and causes the icon's color to match that of the ellipse. Incorrect or unclear pronunciation results in the ball icon wandering’ about the screen or coming to rest in an area not enclosed by an ellipse. By observing the continuous motion of the ball, a speaker gains information about how to adjust his or her pronunciation in order to produce the desired vowel sound.

Pacman Pacman can be played using four vowels to control the movements of the ghost. Several options are available, including selection of the vowels for the directions of movement. More details are available using the help key (F1) as shown on the screen.

Chicken Crossing the Road For this game, two vowels are used to control the up and down movement of the chicken crossing the road. More details about the game can also be found using the help key.

Columns For this game one vowel sound is used to rearrange the colors in the falling column of colors. The arrow keys are used to move the column left and right. More details of the game and setup options can be found using the help key.

MORE ADVANCED COTROL SETTINGS

MLC This switch is a toggle, to either enable or disable non-vowel sounds from recognition as a vowel. The default is enabled, and normally this setting should be left in the enabled mode.

Prefiltering This switch is a toggle, to either enable or disable midfrequency pre-emphasis. Normally, the prefiltering should be enabled, which is the case for program start up.

Help for microphone adjustments Clicking on this button brings up a help screen to better adjust the microphone gain. The VATA program has an overview HELP, available from the top menu. More complete help for operation of the program is available from this. Last update March 21, 2006.