Web-based English Pronunciation Simulator 
for ESL/EFL Learners 

Hyouk-Keun Kim
Department of Linguistics
Georgetown University
37th & O St. NW, Washington, DC 20057, USA
kimh1@gusun.georgetown.edu

Abstract

The KAEPS [Korean Accented English Pronunciation Simulator] system aims to design a Web-based English pronunciation simulator system whose input includes orthographic English words, phrases, or sentences,  and whose output results in three types of English pronunciations in the IPA [International Phonetic Alphabet] symbols: 1) a phoneme-based English pronunciation, 2) a desirable allophone-based American English pronunciation, and 3) one or some possible Korean accented English pronunciation(s) based on the interlanguage (IL) phonology of Korean learners of English. It is written in PERL and its URL is http://epsilon3.georgetown.edu/~kimhk/cgi-bin/kaeps.

1. Introduction 

Most typical English dictionaries provide only phoneme-based and word-based pronunciation information, which is insufficient for ESL/EFL [English as a Second / Foreign Language] learners who wish to obtain more accurate information about English pronunciation. For example, most dictionaries do not indicate the differences between aspirated [k] in key vs. unaspirated [k] in ski and between light [l] in late vs. dark or velarized [] in tale. In addition, many phonological phenomena such as palatalization, as in did you [du], apply not only within words but also across word boundaries. However, to my knowledge, there exists no dictionary which deals with the pronunciation of phrases or sentences. Most adult ESL/EFL learners have accents when speaking English. Such an interlanguage phonology is, in many cases, influenced by their native tongue. If the learners recognize the reason or source of their mispronunciation of English, they would have a better chance to improve their English pronunciation.

2. Architecture of KAPES

The system uses the CGI [Common Gateway Interface], which allows users to test the pronunciation of any English word, phrase or sentence on the Web. 
The input is any English orthographic representation typed by the Web users. The Input Detector detects the input, separates punctuation from the words, puts a word boundary marker between words, and sends the string of words to the Phoneme Extractor.
The Phoneme Extractor dispatches the string of words to a CMU American English pronouncing dictionary and extracts ASCII-based phoneme symbols of each word.
The English Allophone-based Pronunciation Generator takes the string of phonemes and generates appropriate allophones according to English phonology.
The Korean-accented English Pronunciation Generator takes the same string of phonemes and generates possible Korean-accented English pronunciations according to Korean-to-English IL phonological constraints.
Finally, the IPA Transformer converts ASCII-based symbols into IPA symbols, which are then displayed to the users. The following is an example of an output for an input such as " Daddy, please pick me up at your company."

(1)	The phoneme-based pronunciation is
		[d'di pl'iz p'k m'i 'p 't j'r k'mpni]
An allophone-based pronunciation is
		[d'i pl'iz p'k()m'i 'p()'t()j'r 
k'mpni] tapping (1) aspiration (6)
A possible Korean-Accented pronunciation is
		[ddi pli pi mi p  u 
kmpni] epenthesis (2), voicing (3), /r/-
deletion (1), /n/-insertion (1), nasalization 
(2)

3. Facilities and Limitation of KAPES

KAEPS has two systems: one is a rule-based system using feature geometry, and the other is an optimality theoretic constraint-based system (Kim, 1998) adopting Hammond (1997). The latter displays only Korean-accented English pronunciation symbols, but it shows all the processes how the phonological constraints eliminate all unnecessary candidates except an optimal (here, a possible Korean-accented English) form. 
There are other subsidiary Web pages describing phonological background, IPA symbols tips, glossary, references, etc. to help the understanding of the common users. Some examples of waveforms and spectrograms linked to actual sounds are given, too.
Korean learners of English can be provided with information about possible Korean-accented English pronunciation and also about corresponding Korean phonology, so they may know why they tend to mispronounce some phrases in a certain way. In such a sense, KAEPS can lead to the development of a CALL [Computer Assisted Language Learning] program and would be useful to Korean learners of English, EFL teachers with Korean students, or IL phonology researchers.
There are some limitations with the current KAEPS system: 1) no speech technology such as speech recognition or speech synthesis is used, 2) only one possible pronunciation among various options in each category is displayed  it is impossible to display all different kinds of allophones or different levels of interlanguage pronunciations, but it would be more useful to display several possible cases 3) it will be more effective to use a syllabified English Pronunciation Dictionary  that is being developed, 4) it is limited only to Korean-accented English  but easily expandable to other types of accented English.

4. Conclusion

The KAEPS system was designed to simulate allophone-based and Korean-accented English pronunciation, and is still being revised for more detailed information. 

Reference

Church, Kenneth W. 1987. Phonological Parsing and 
Lexical Retrieval. In Uli H. Frauenfelder and 
Lorraine Komisarjersky Tyler, eds., Spoken 
Word Recognition. Cambridge, MA: MIT Press.
Hammond, Michael. 1995. Syllable parsing in English and French. Ms., University of Arizona.[ROA-58].
Hammond, Michael. 1997. Parsing in OT. Ms., 
University of Arizona. [cmp-lg/9710004].
Kim, Hyouk-Keun. 1998. Generating Interlanguage 
Syllabification in Optimality Theory. In the proceedings of the COLING-ACL '98 workshop on the Computation of Phonological Constraints, Montreal, Canada, 1-10.
Kreidler, Charles W. 1989.  The Pronunciation of 
English: A course Book in Phonology. Cambridge, MA: Basil Blackwell Inc.
Ladefoged, Peter. 1993.  A Course in Phonetics, 3rd 
edition. Orlando, FL: Harcourt Brace Jovanovich, Inc.