UCLA Phonetics Lab

ELECTROPALATOGRAPHY (EPG) 


The Phonetics Lab acquired its Kay Palatometer Model 6300 in 1992, with a dissertation improvement grant to Dani Byrd, and much use has been made of it since then. A DOS program limited to a low sampling rate (12.8 kHz for the audio, 100 Hz for the EPG), it requires an older type of PC with two full-size slots for the Palatometer and CSL boards.  

I. Basic Experimental Steps to Follow

1. Get a grant (or inherit money).
Pseudo-palates are expensive, and the lab does not pay for them. If you want to work with speakers who do not already have pseudo-palates, you will need about $1300 per speaker.  (However, it is possible that Kay Elemetrics is no longer making pseudo-palates - contact them before making any such plans.)  Otherwise, see the list of past speakers below.
2. Human subjects approval.
Because speakers put something in their mouths, this counts as an invasive procedure. You need approval by the committee, and informed consent by the speaker, before you can proceed to step 3.  This is true even for speakers who have served as subjects in other experiments.

3. Custom pseudo-palate.
These can no longer be obtained for our system. See below for current possible speakers.

4. Get used to pseudo-palate.
We usually have our speaker wear his or her pseudo-palate to get used to it; the more the better, but usually for an hour of normal activity to accommodate and diminish any salivation response (Byrd et al. 1995).

5. Do the experiment.
6. Analyze the data.
The Palatometer manual contains plenty of information on displaying data frames, etc., and on its interactive version of the region definition/percent analysis routine. But the DOS version of this routine, developed here, is what we mostly use, because it allows batch processing and ASCII, as well as binary, output. Experienced people include: Pat K., Taehong C., Sahyang K.. For a description of indices defined on percent-contact data, see Byrd, Flemming, Mueller & Tan (1995), Using regions and indices in EPG data reduction, J. Sp. Hear. Res. 38, 821-827.

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II. How we normally analyze EPG data.
1. Obtain 'Percent.exe' file.
       This software, commissioned by Dani Byrd, calculates contact profiles for user-defined regions of the palate.  On Jasmine, it is in the pal\output\ directory
       FORMAT:  PERCENT [.nsp file name] [.def file name] [.usr file name]


III. Displaying Palatometer in 3-D

 

                                           3D Wire Model Palate "Flying Palates"
 

 Sample Movies.  Click icons to see movies.
 



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IV.  Domain-initial strengthening : French and Korean

Keating et al (1998, LabPhon 6) and many other studies supported by NSF grant #SBR 9511118 (to P. Keating) showed, in their EPG studies of English, French, Korean, and Taiwanese, that consonants have greater linguopalatal contact in a domain-initial position than in a domain-medial position and that this effect is in general cumulative: the linguopalatal contact becomes greater as the domain is higher in the prosodic hierarchy.  Such cumulative effect was more pervasive in one language (e.g., Korean) than in another (e.g., English).  Here, we put some results from French and Korean with representative EPG contact figures and sounds (.WAV format).
(1) French  [Please scroll down to "examples."]

Figure 3.  Differences in linguopalatal contact for [n] in French as a function of prosodic position.
  Examples:
[n]s in bold are target segments which occur in different prosodic positions.  Examine the corpus and click each sentence to hear the sound, as you wish.  (The Speaker is C. Fougeron.)
See French references below.

(2) Korean
The figure below shows that the linguopalatal contact varies depending on prosodic position in the direction Ui > IPi > APi > Wi (Wi > Si).  (Note: Wi vs. Si was examined separately.)


Figure 4.  Differences in linguopalatal contact for [n] in Korean as a function of prosodic position. Wi vs. Si was examined separately.
Examples:
[n]s in bold are target segments which occur in different prosodic positions.

Examine the corpus and click below  to hear the sound, as you wish.  (The voice is T. Cho.)

    (a)   Ui IPi APi Wi   (b) Wi Si

See Korean References below:
 

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V.  Present and former colleagues at UCLA who have pseudo-palates

Note: Those whose email addresses are given here have indicated their willingness to serve as subjects for other researchers.  However, remember that data collection at UCLA requires UCLA human Subjects Protection approval.
 

VI. Some References of EPG studies done at UCLA



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Last updated: June 2011 by P. Keating