Proceedings of the 6th International Conference on Spoken Language Processing (ICSLP-2000), Vol.III, pp.398-401. 1

SPOKEN LANGUAGE CORPUS FOR
MACHINE INTERPRETATION RESEARCH
Yasuyuki Aizawa1Shigeki Matsubara2 3
Nobuo Kawaguchi1 3
Katsuhiko Toyama1 3
Yasuyoshi Inagaki1;;;

Graduate School of Engineering, Nagoya University
Faculty of Language and Culture, Nagoya University
3 Center for Integrated Acoustic Information Research, Nagoya University
Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japanemail: faizawa, matu, kawaguti, toyama, inagakig@inagaki.nuie.nagoya-u.ac.jp12ABSTRACTThis paper describes a database consisting of speech andlanguage, which we are currently constructing for the purpose of research on machine interpretation. The database
contains bilingual data of lectures and dialogues. We
have collected of speech about 72 hours in total and transcribed it into the text manually. We have investigated thedatabase in order to acquire empirical knowledge of humaninterpretation. In this paper, we report the characteristicfeatures of spoken language by Japanese-to-English interpreters.

1. INTRODUCTION

Spoken language translation has been an important research topic in recent years. In fact, some dialogue translation systems have been developed so far. The systems,
however, are used in a limited dialogue domain and translate only speech of speci c types. Furthermore, the users
are expected to speak only in one's own turn. This context
suggests that the system is desired to be more natural andintelligent.
It has been proved that spoken language corpora are very
useful for many natural language processing tasks during
the decade of the 1990s. Especially, parallel corpora haveplayed an e ective part in the research on spoken language translation[1][2]. Because they provided the empirical knowledge of human interpreters and have been used
as examples in corpus-based translation processing.
This paper describes a database of parallel spoken language, which we are currently constructing. It has thefollowing characteristics:
 Speech is interpreted in a simultaneous fashion to realize natural cross-lingual communication.
 The beginning time and end time are given to eachutterance unit of spoken dialogues.
 In addition to cross-lingual dialogues through interpreters, lectures with the interpretation are also contained.
 A spoken lecture read out by one native speaker isinterpreted by two or more interpreters whose skill isdi erent from each other.
Our corpus will be useful for the development of an advanced spoken language translation system. Furthermore,

it could be used for investigating human interpreting mechanism and building an interpreting theory.
In fact, we have investigated the database to acquire empirical knowledge of Japanese-to-English interpreting. In
consequence, we have con rmed frequent utilization of two
kinds of techniques: sentence segmentation and phraseorder inversion.
This paper is organized as follows: The next section describes the contents of the database. Section 3 shows how
we have constructed the database. Section 4 reports theresult of investigating the database.

2. DATABASE DESIGN

We are constructing a parallel spoken language database.

2.1. Contents

Most of the existing parallel corpora supply only crosslingual dialogue data[1][2]. However, we would like to emphasize that parallel data of lectures is also valuable. Actually, there is a big demand for interpreters of oral presentation in international conferences and of speeches byinvited foreign speakers. Constructing such a corpus may
enable us to develop an interpretation system for lectures.
Our database supplies not only dialogue data but also lecture data spoken in English and Japanese. As the dialoguetask, we adopted \travel arrangement" which have beenadopted in a lot of spoken language corpora so far[1][2].
Lectures were done according to the transcriptions of real
spontaneous lecture data. Politics, economy, personal reminiscence, and so on have been chosen as themes.

Table 1: Contents of the databaseconversational stylelanguageinterpreting style: dialogue/lecture: English/Japanese: simultaneous interpreting

2.2. Simultaneous Interpreting
Interpreting a dialogue in a simltaneous fashion works toavoid interrupting the coherency of communications. In alecture, a speaker often uses aids which helps the listeners
to understand, such as slides and pictures. Listeners canProceedings of the 6th International Conference on Spoken Language Processing (ICSLP-2000), Vol.III, pp.398-401. 2
refer to them simultaneously through simultaneous interpreting. These manners demand that the interpreting besimultaneous. In our corpus, every source of speech has
been interpreted by simultaneous interpreter. To explore
the relationship between skill in interpretation and interpreting results, a spoken lecture read out by one native
speaker is interpreted by two or more interpreters whoseskill is di erent from each other.

3.3. Current Status
Currently, we have collected the speech of about 72 hours
in total and transcribed them into texts of 22,229 sentences, as Table 2 shows.

Table 2: Current statusrecording time(hours)

3. DATA COLLECTION
3.1. Recording

The recording was carried out in an internal room. Microphones (Sony Dynamic Microphone F-730) were used forstereo DAT recording (Sony Digital Audio Tape-Corder
TCD-D100), and one recording channel was assigned toone speaker. Each speech was converted into a wave format, 16 bit, 16 kHz.

3.2. Transcription

Speech was transcribed into texts manually. Then we gavethem tags that express linguistic phenomena such as llers,
stagnated utterances and mispronunciations. Regarding
dialogue, speech was segmented into some utterance units
by pauses. The beginning time and end time are given to
every utterance unit of spoken dialogues. It enables us toobtain a time chart. Figure 1 shows an example of thetime chart.

utterances(sentences)dialoguelecturetotal
dialoguelecture
total

32
40
72
8,676
13,55322,2294. CORPUS INVESTIGATION
Simultaneous machine interpreting is one of the mostambitious applications of spoken language processing.
It requires incremental analysis and transfer of sourcelanguage. There exists a di erence in word-order between source language and target language, especially between linguistically distant languages such as English andJapanese. Generally, a verb is located on the earlier part ofan English sentence. On the other hand, a verb often appears at the last part of a Japanese sentence. Therefore,
it is dicult to decide the English verb before a whole
Japanese sentence is uttered.
JapaneseWatashi-wa

I bought(verb)
English

Kono-Mise-deHon-wo(verb)
Kai-mashita

a book at the store.

Figure 2: Di erent word-order between Japanese and English

Figure 2 shows the example. A Japanese verb \Kaimashita" appears at the last part of the sentence\Watashi-wa Kono-Mise-de Hon-wo Kai-mashita". So, aninterpreter can utter only \I" before \Kai-mashita" is uttered.
Not only verb, but also negating word and interrogative
are located on the later part in a Japanese sentence. Besides, Japanese sentences are allowed to be uttered in various word-order. Thus, boundaries of spoken Japanese sentences are very ambiguious. As a result, it is dicult todetermine the timing to output for plausible translation.

Figure 1: An example of the time chart. The leftmost
number indicates the time from the beginning of the dialogue (minute:second). The Bar on the scale exhibits theduration of each utterance unit (in order from left: English speaker, English-to-Japanese interpreter, Japanese
speaker, Japanese-to-English interpreter). The rightmost
text is utterance unit.

They may inhibit the simultaneity of Japanese-to-Englishinterpretation.

4.1. Interpreting Technique

Human interpreters generally use particular empiricalknow-how to overcome the diculties[3][4][5]. Therefore,
we can say that it is e ective for a simultaneous interpreting system to utilize such the know-how[6][7]. We
found some kinds of techniques for Japanese-to-English

Proceedings of the 6th International Conference on Spoken Language Processing (ICSLP-2000), Vol.III, pp.398-401. 3
interpretation from our database. These are explained below. Each explanation is followed by an example.
,and 3 denotes a source sentence, the interpreting result
and the normal translation respectively.

J) E)

E)

1)sentence segmentation

One Japanese sentence is translated into two or more
English sentences by using demonstrative pronounsuch as \that" and \it". Using this technique, aninterpreter becomes receptive for the later part of aJapanese sentence.

J) ソフトウェア工学というものは実験的な分野だという言い方もできるでしょう.
E) The software engineering is the experimental
eld. You may be able to say that way.
E3) You may be able to say that the software engineering is the experimental eld.

2)counterchanging phrases

Prepositional phrases or adverbial phrases are usually on the last part in English sentences. However, if
a phrase is uttered in an early stage of a Japanese utterance, an interpreter can translate it into English asa prepositional phrase or an adverbial phrase before
the English sentence.
そこに並べられた車の中で 私が選んだのはスバル R2 という車でした.
Among those cars what I chose was Subaru R-2.
3 What I chose was Subaru R-2 among those cars.

J)
E)
E)

3)transformation into the passive voice

In a Japanese sentence, an objective word is allowed
to be uttered before a subject word. In such a sentence, to translate it into a sentence of passive voice ishelpful for simultaneous interpretation. This transformation means an exchange of the structural subject
and object. Thus, it enables interpreters to utter inadvantageous word-order.

J) 初 め て あ の アー バ ン リ ゾー ト と い う 言 葉 を使い始めました.
E) At that time for the rst time ever, the word urban resort was used.
E3) At that time, we used the word urban resort for
the rst time ever.

4)summarization

Depending on the information density of the source
utterance, an interpreter summarizes it in an appropriate degree. Summarization helps an interpreter tocatch up with a speaker.

J)

二月から四月と八月から十月までがこの島の雨期にあたります. 乾期は四月から八月、十月から二月までの期間.

E) One from February through April and from Au-

gust to October are rainy season. And theremaining periods are in the dry season.
3 One from February through April and from August to October are rainy season. And dry season
is from April to August and from October toFebruary.

E)

Table 3: Investigated sentences
speakerinterpretersentences
1,617
2,034

We investigated how often these techniques are utilized bysimultaneous interpreters.
12 sessions of Japanese lectures composed of 1,617
Japanese sentences and 2,034 English sentences, which
are aligned manually, are used. Then, the appearances of1)sentence segmentation and 2)counterchanging phrases inthese sessions have been counted.
Table 4 shows the numbers. \Sentence segmentation" appears in 58 appearances, and the 28 Japanese sentences
contained an expression \という"1 , and are segmented
there.

Table 4: Sentence segmentation
key wordという1others
total

number2830
58

We found several keywords in the Japanese sentences containing \counterchanging phrases". Table 5 shows the keywords and the numbers of their appearance.

Table 5: Counterchanging phrases
key word
年 (year)
時 (time)中 (in/on)において (in)頃 (at about)otherstotal

number
59
34
22
17
10
279
421

4.2. Towards an Interpreting System
As described at the beginning of this section, a Japanese
sentence has a predicate in the latter part. An interpretingsystem has two options. One is to wait until the wholesentence is inputed. The other is to decide a plausible
aspect at the middle of the input sentence, and output thepartial interpretation. In this case, if the output is revealed
to be wrong by the latter part, the system rephrases tomodify the intent of the output. The former spoils thesimultaneity, and the latter should take a risk to rephrase.
If the system has \sentence segmentation" rules, the system will be able to modify the intent of the output without
rephrasing for certain types of Japanese sentences. The
key word \という" will play an important role to construct\sentence segmentation" rules.
1 A phrase \という" expresses a kind of quotation.

Proceedings of the 6th International Conference on Spoken Language Processing (ICSLP-2000), Vol.III, pp.398-401. 4\Counterchanging phrases" means that speci c kinds ofphrases can be interpreted immediately. Our investigation
will help to learn what kinds of Japanese phrases are allowed to be interpreted immediately, and how they should
be interpreted into English.

5. CONCLUSION

This paper have described a spoken language databasewhich we are constructing for research on spoken languagetranslation. The database consists of parallel corpus oflectures and dialogues spoken in English and Japanese.
Also, we have investigated the database and con rmed
some kinds of techniques for simultaneous interpreting to
be utilized frequently. We will continue collecting parallel data, and introduce the know-how acquired throughmore investigation in-depth into a simultaneous interpreting system[7].

6. ACKNOWLEDGEMENTS

The authors are grateful to Dr. Toshiyuki Takezawa andDr. Eiichiro Sumita for their helpful comments. The collection and transcription of the spoken language data havebeen carried out cooperatively with Inter Group Corporation. The authors wish to thank specially Mr. Masafumi
Yokoo for his contribution. This work is partially supported by the Grant-in-Aid for COE Research of the Ministry of Education, Science, Sports and Culture Japan andby The Telecommunications Advanced Foundation.

7. REFERENCES

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2. Morimoto, T., et al.: Speech and Language Databasefor Speech Translation Research, In, pp.1791-1794 (1994).
3. Mizuno, A.: On Simultaneous Interpretation fromJapanese into English, In, Vol.5, No.5, pp.4-21(1995). (in Japanese)
4. Yang, C.: Segmentation in Slight Translation fromJapanese into Chinese, In, Vol.7, No.1, pp.4-17(1997). (in Japanese)
5. Kamei, C.: A Case Study of Japanese-English Simultaneous Interpreting: In, Vol.7, No.2, pp.96-103(1998). (in Japanese)
6. Mima, H., Iida, H. and Furuse, O.: Simultaneous Interpretation Utilizing Example-based Incremental Transfer, In, pp. 855-861 (1998).
7. Matsubara, S., Iwashima, K., Kawaguchi, N., Toyama,
K. and Inagaki, Y.: Simultaneous Japanese-English Interpretation based on Early Prediction of English Verb,In, pp. 268-273 (2000).

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