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論文

The Effect of the Attentional Aspect of Language Processing on
Sound Perception in L2 Repeating Compared to L2 Shadowing forJapanese EFL Learners
NAKANISHI, Hiroshi(Tohoku Gakuin University)

1. Introduction
English-repeating training requires learners to listen to a certain amount ofauditory input and then repeat it during a pause following the input. This training issimilar to shadowing training, which requires learners to reproduce the model sounds
almost simultaneously with the input. Both trainings require learners to reproduce
model sounds, but the cognitive processes involved in shadowing and repeating arevery different (Kadota, 2007). The former is an immediate online repetition task,
which forces learners to focus on sounds themselves, whereas the latter is an offline
task, which provides learners with sufficient time to analyze the input semantically,
syntactically, and pragmatically before they reproduce the input. Shiki et al. (2013)
empirically investigated the cognitive difference between shadowing and repeating bycomparing type of reproduced words (i.e., content word and function word) between
two trainings. The results indicated that participants who engaged in shadowing
practices more successfully reproduced content words (i.e., “eleven thousand” and“Tokyo”), which are typically pronounced strongly and loudly, than did those who
engaged in repeating practices. On the other hand, participants who engaged in
repeating practices more successfully reproduced function words (i.e., “from” and “the”),
which are typically pronounced weakly and quickly, than did those who engaged inshadowing practices. The study suggested that participants who performed shadowing
rehearsed only phonologically emphasized input (i.e., content words) that they could
catch under rigorously time-pressured conditions and that they had little time for
additional processing (i.e., semantic, syntactic, or pragmatic processing), whereas
repeating enables learners to add function words, which L2 learners find difficult tocatch, when they reproduce the input as a full sentence.
As mentioned above, the main cognitive difference between shadowing andrepeating is learners’ attentional direction during these tasks. The former directs theirattention to phonological aspects, whereas the latter directs their attention to content
aspects (i.e., semantic, syntactic, or pragmatic). The repeating process includes various
types of processing (i.e., semantic, syntactic, and pragmatic), such that it is difficult for

NAKANISHI, Hiroshi

2learners to identify what language aspect they should focus on during repeating tasks.
This study investigates whether attentional direction to semantic, syntactic, or
pragmatic aspects of language processing during repeating tasks affects repeating
performance (i.e., the rates of successfully shadowed syllables (henceforth,reproduction rates)
2. Literature Review
In repeating practices, the language processing employed by learners includes
syntactic, semantic, and pragmatic processing. Each instance of language processing
consumes working memory resources, whose capacity is strictly limited (Just &Carpenter, 1992). Therefore, efficient processing for each aspect (i.e., semantic,
syntactic, or pragmatic) is a key supporting factor of repeating performance, more sofor L2 than for L1 learners, because L2 processing is more resource consuming than L1
processing (Geva & Ryan, 1993; Miyake & Friedman, 1998).
To explore the relationship between reproduction rates and the semantic,
syntactic, and pragmatic aspects of language processing, participants’ attentional
direction should be manipulated systematically under experimental conditions.
Several L2 language processing experiments have manipulated participants’ attention
to certain language-processing aspects according to the type of task they are assigned
during reading or listening comprehension. For example, Leeser, Brandl, andWeissglass (2011) required L2 Spanish learners to read grammatically correct andincorrect sentences in a self-paced reading task and to perform a grammaticality
judgment task. In addition, Hahne and Friederici (2001) measured event-related
potentials when Japanese L2 learners of German were engaging in grammaticality
judgment tasks after listening to German sentences in order to explore the cognitive
mechanism underlying learners’ attention to aspects of syntactic processing.
Following these experimental method, Nakanishi and Yokokawa (2011)
manipulated participants’ attention to syntactic, semantic, and pragmatic aspects by
imposing semantic, grammaticality, or pragmatic judgment tasks during the reading ofsentences. The study demonstrated that among these processing aspects, syntactic
processing places the heaviest cognitive load on working memory resources forJapanese EFL learners. The authors created four types of reading span tests (RSTs): a
standard version (RST 1), a semantically focused RST (RST 2), a syntactically focused
RST (RST 3), and a pragmatically focused RST (RST 4). The main results showed thatthe recall scores of the syntactically focused RST (RST 3) were significantly lower thanthose of the other RSTs, suggesting that syntactic processing places a heavy cognitive
load on working memory resources, thereby leaving few resources for storage functions
while Japanese EFL learners are performing RSTs.

The Effect of the Attentional Aspect of Language Processing on Sound Perception in
L2 Repeating Compared to L2 Shadowing for Japanese EFL Learners

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Nakanishi (2016) applied the framework of Nakanishi and Yokokawa (2011) to a
study of shadowing in order to investigate whether attentional direction (i.e., syntactic,
semantic, or pragmatic) during shadowing practices affects learners’ shadowing
performance (i.e., reproduction rates). The main results indicated that reproduction
rates during syntactically focused shadowing do not differ significantly from those
associated with other types of shadowing (i.e., prosody shadowing, semanticallyfocused shadowing, and pragmatically focused shadowing), even though processing
accuracy scores were the lowest during syntactic shadowing. The results suggested
that Nakanishi’s (2016) shadowing study showed that L2 learners’ attentional
direction to syntactic, semantic, or pragmatic aspects of language processing during
shadowing does not affect shadowing reproduction rates. However, this may be thecase because shadowing does not provide learners with enough time to analyze theinput semantically, syntactically, or pragmatically. Therefore, the present study
explores whether learners’ attentional direction (i.e., semantic, syntactic, or pragmatic)
during repeating tasks influences how successfully they reproduce model sounds.
3. Purpose
This study examined whether directing participants’ attention to semantic,
syntactic, or pragmatic processing aspects during repeating tasks influences theirreproduction rates during repeating. Therefore, three research questions (RQs) wereaddressed:
RQ1: Do reproduction rates vary depending on the type of repeating (i.e., semantic,
syntactic, or pragmatic)?
RQ2: Do processing accuracy scores vary depending on the type of repeating (i.e.,semantic, syntactic, or pragmatic)?
RQ3: Do repeating performances (i.e., reproduction rates and processing accuracy
scores) vary depending on learners’ English proficiency?
4. Method
4.1 Participants
A total of 35 Japanese EFL undergraduate students (10 males and 25 females)
participated in the study. They were recruited from one private university and one
public university in Japan. Their ages ranged from 19 to 25, with an average of 20.86
years. Their proficiencies ranged from lower intermediate to advanced according totheir Oxford Online Placement Test (OOPT), with scores ranging from 19 to 103 (M =59.23). The participants were divided into two groups according to their OOPT total
scores (reading score plus listening score), such that the scores were significantly
different between the group with higher levels of English proficiency (N= 18, M = 74.44,

NAKANISHI, Hiroshi

4range: 58–103, S.D. = 13.156) and that with lower levels of proficiency (N= 17, M =43.12, range: 19–56, S.D. = 12.129) (t(33) = 7.312, p < .01). The participants weredrawn from the same population as in Nakanishi (2006).
4.2 Materials
Four types of repeating tasks, each including 16 sentences, were created so thatthe average familiarity of sentences (Yokokawa et al., 2006) and the average number ofsyllables per sentence were set to be statistically equal among repeating tasks 1–4(familiarity: F(3,63) = 1.782, ns., syllables: F(3,63) = 1.162, ns., respectively). All thewords within the experimental sentences used in repeating were high-familiarity
words for Japanese EFL learners, each with a rating of 5.00 or more on a seven-point
scale (Yokokawa et al., 2006). As these sentences constituted model speech used in
repeating, these sentences were recorded by a male American native speaker ofEnglish, at a speaking rate of approximately 135 words per minute.
4.3 Procedure
All participants completed four types of repeating tasks: a standard repeatingtask, a semantically focused repeating task, a syntactically focused repeating task, anda pragmatically focused repeating task. Each participant was tested individually on a
Windows computer using SuperLab Pro5 psychological experiment software. Eachparticipant’s repeating voice were was recorded using digital sound recorders, so that
their performance could be analyzed. The order in which the four versions of therepeating tasks were administered was counterbalanced.
(1) Standard version of the repeating task
This repeating task required participants simply to repeat the sentence they
heard. The repeating procedure was as follows. The fixation marker was presented forone second on a computer monitor, and the model sound was then relayed to theparticipants through a headset (e.g., At the beach, the mother saw the baby boy.). The
participants were required to repeat the oral input immediately after they heard it andthen to immediately press the space bar; the next sentence was then heard through theheadset following the fixation mark. The participants were then asked to repeat themodel sounds once more. This procedure continued until they had repeated 16
different sentences, when an instruction indicated that the session was over.
(2) Semantically focused repeating task
This repeating task aimed to direct participants’ attention mainly to the semantic
aspect. The Japanese-translation verification task was incorporated into the standard
version of the repeating task. The repeating procedure was as follows. After theparticipants had repeated the experimental sentence, the Japanese equivalent of theThe Effect of the Attentional Aspect of Language Processing on Sound Perception in
L2 Repeating Compared to L2 Shadowing for Japanese EFL Learners

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previous English sentence appeared on the monitor. The participants were required topress the B key if the translation was correct (e.g., The woman had to go to thecompany party. その女性は、会社のパーティに行かなければならなかった。) and N if it
was incorrect (e.g., As a young student, he was my friend. 若い頃、私は彼のことを知らなかった。). Half of the translations were correct and half were incorrect; that is, acrossthe entire test set, eight English sentences appeared with correct Japanesetranslations, and eight appeared with incorrect Japanese translations. This procedurecontinued until they had repeated 16 different sentences with Japanese verification
tasks, when the monitor indicated the session was over.
(3) Syntactically focused repeating task
This repeating task aimed to direct participants’ attention mainly to the syntactic
aspect. The grammaticality judgment task was incorporated into the standard versionof the repeating task. The repeating procedure was as follows. The participants wererequired to repeat the model speech and press the B key if the sentence wasgrammatical (e.g., The company manager finally accepted her support.) and N if it was
ungrammatical (e.g., The school meeting was changed his morning schedule.). Half ofthe sentences were grammatical and half were ungrammatical, with the condition thatacross the entire test set, eight sentences appeared in their grammatical forms andeight in their ungrammatical forms. This procedure continued until they had repeated
16 different sentences with grammaticality judgment tasks, when the monitor
indicated that the session was over.
(4) Pragmatically focused repeating task
This repeating task aimed to direct participants’ attention mainly to thepragmatic aspect. The pragmatic judgment task was incorporated into the standard
version of the repeating task. The repeating procedure was as follows. The participants
were required to repeat the model sound and press the B key if the sentence waspragmatically plausible (e.g., To help the sick, the girl became a nurse.) and N if it was
implausible (e.g., We always wear many jackets in summer.). Half of the sentenceswere pragmatically plausible and half were implausible, with the condition that acrossthe entire test set, eight sentences appeared in their pragmatically plausible forms andeight in their pragmatically implausible forms. This procedure continued until they
had repeated 16 different sentences with pragmatically focused judgment tasks, whenthe monitor indicated that the session was over.
5. Results
5.1 Descriptive statistics for repeating tasks
The following data obtained from participants’ responses during the repeating
practices were statistically analyzed: (1) reproduction rates, which were based on the

NAKANISHI, Hiroshi

6number of syllables produced correctly by the participants in all types of repeatingtasks, and (2) processing accuracy scores (henceforth, accuracy scores), or the numberof sentences correctly processed by the participants in the repeating tasks
accompanied by translation verification, grammaticality judgment, and pragmatic
judgment tasks (REs 2-4).
Table 1 presents the rates for successfully reproduced syllables. The total numberof syllables used in the repeating tasks differed among the tasks (RE1 = 178, RE2 =191, RE3 = 193, RE4 = 195); for ease of comparison, each reproduction rate will be
graded based on a score of 100. A one-way analysis of variance (ANOVA) indicated thatthe differences among the tests were not significant: F(3,139) = 2.109, ns., partial η2= .044.
Table 2 illustrates the number of sentences processed accurately. The one-way
ANOVA indicated that there was a significant difference among the tests: F(2, 104) =61.950 (p < .01), partial η2 = .548. Multiple comparisons showed that the accuracy
score was significantly lower in RE3 than in RE2 and RE4 (p < .01) and that theaccuracy rate was significantly lower in RE4 than in RE2 (p < .01).
These results indicate that the repeating type did not significantly affect thesuccess with which syllables were reproduced (RQ1). However, processing accuracy
scores differed according to repeating type. This was especially notable with RE3, in
which participant attention was directed to the syntactic aspect, and processing
accuracy was significantly the lowest (RQ2). This result—namely, that syntactic
processing is more difficult and resource-consuming than other types of processing (i.e.,semantic and pragmatic processing) for Japanese EFL learners—is in line with theresults of Nakanishi and Yokokawa’s (2011) reading study and those of Nakanishi’s(2016) shadowing study.
Table 1 Reproduction rates of repeating tasks
RE1

RE2

RE3

RE4

Average

73.72

73.91

67.10

70.70

Minimum

37.91

31.77

32.65

41.80

Maximum

100.00

97.40

96.43

98.41

S.D.

12.94

13.25

13.75

12.11

Note. n = 35; mark range: 0–100.

The Effect of the Attentional Aspect of Language Processing on Sound Perception in
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Table 2 Accuracy scores of repeating tasks
RE2

RE3

RE4

Average

14.37

8.66

12.23

Minimum

8.00

4.00

8.00

Maximum

16.00

16.00

15.00

S.D.

1.90

2.63

1.90

Note. n = 35; mark range: 0–16.

5.2 Repeating performances by English proficiency
Table 3 illustrates the mean reproduction rates by participants’ proficiency. A 2(proficiency) × 4 (RE type) ANOVA revealed significant main effects of both proficiency(F(1,139) = 33.924, p < .01, partial η2 = .204) and RE type (F(3, 139) = 2.569, p = .057,
partial η2 = .055). However, there was no significant interaction between proficiency
and RE type (F(3,139) = .046, ns., partial η2 = .001.).
Table 4 presents the average accuracy scores for learners with high and low
proficiency. A 2 (proficiency) × 3 (RE type) ANOVA indicated significant main effects ofproficiency (F(1,104) = 7.855, p < .01, partial η2 = .074) and RE type (F(2, 104) = 65.156,

p < .01, partial η2 = .568). However, proficiency did not yield a significant interaction
with RE type (F(2,104) = .206, ns, partial η2 = .004).
As shown in Tables 3 and 4, high-proficiency participants reproduced significantly
more syllables and processed sentences more accurately than low-proficiency
participants; these results speak to RQ3.
Table 3 Reproduction rates of repeating tasks by proficiency
RE1

SH2

SH3

SH4

High

Low

High

Low

High

Low

High

Low

Average

78.94

68.20

79.92

67.55

72.45

61.43

76.69

64.36

Minimum

62.09

37.91

60.94

31.77

52.04

32.65

59.26

41.80

Maximum

100.00

83.52

97.40

83.33

96.43

81.12

98.41

85.71

S.D.

11.09

12.73

11.06

12.63

13.14

12.34

10.29

10.79

Note. High n = 18, Low n = 17; mark range: 0–100.

NAKANISHI, Hiroshi

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Table 4 Accuracy scores of repeating tasks by proficiency
RE2

RE3

RE4

High

Low

High

Low

High

Low

Average

15.00

13.71

9.33

7.94

12.61

11.82

Minimum

11.00

8.00

4.00

5.00

9.00

8.00

Maximum

16.00

16.00

16.00

12.00

15.00

15.00

S.D.

1.50

2.08

3.22

1.64

1.82

1.94

Note. High n = 18, low n = 17; mark range: 0–16.

5.3 Correlation analysis among task performances
Table 5 presents the correlations between OOPT scores (i.e., total score, reading
section score, and listening section score) and repeating performances (i.e.,
reproduction rates and accuracy scores). Total English proficiency scores produced (ortended to produce) significant correlations with repeating performances, suggestingthat higher-proficiency learners tend to exhibit better repeating performances; thisfinding is consistent with the results discussed in section 5.2.
Table 5 Correlation among the OOPT and repeating performances
Reproduction
rates

Accuracyscores

Total

Reading

Listening

RE1**0.67**0.59**0.63

RE2**0.73**0.63**0.71

RE3**0.69**0.63**0.63

RE4**0.75**0.67**0.71

RE2

*0.50

*0.41

**0.51

RE3

†0.31

0.23

*0.35

RE4

*0.39

*0.35

*0.37

** p < .01, *p < .05, † .05 < p < .01

6. Discussion
The first goal of the present study was to explore the relationship between
certain aspect of processing (i.e., semantic, syntactic, or pragmatic) to which learners’
attention is directed and repeating performances (i.e., the rates of successfully
reproduced syllables) using various types of RE tasks. Tables 1 and 2 indicate that thesuccessful reproduction rates of speech input during repeating do not significantly
differ in relation to the language processing types, suggesting that the aspect oflanguage processing to which participants pay attention during repeating may notinterfere with or enhance their sound perception performances. This result is
consistent with Nakanishi’s (2016) shadowing study.

The Effect of the Attentional Aspect of Language Processing on Sound Perception in
L2 Repeating Compared to L2 Shadowing for Japanese EFL Learners

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However, when this study’s repeating data and Nakanishi’s (2016) shadowing
data were statistically analyzed together using a 2 (task: SH/RE) × 4 (type: type 1–4)
ANOVA, the main effects for both task and type were significant (F(1,280) = 276.556, p< .01, partial η2 = .504, F(3,280)=3.534, p < .05, partial η2 = .038, respectively), butthere were no significant interactions between task and type (F(3,280) = .818, ns.,
partial η2 = .009). Furthermore, multiple comparisons showed that the reproduction
rates of type 3 were significantly lower than those of type 1 (p < .05) and that the
reproduction rates of RE were significantly lower than those of SH (p < .01). This
statistical analysis showed that there is a trade-off relationship between syntactic
processing and reproduction rates during shadowing and repeating, suggesting thatsyntactic processing consumes considerable working memory resources, leaving few
resources for sound perception.
In addition, it is possible that reproduction rates in repeating were significantly
lower than those in shadowing because repeating is a more cognitively demanding taskwith respect to working memory, which consists of the phonological store and thephonological loop. The former serves to hold the phonological representations thatdecay over time, whereas the latter serves to refresh the representations through arehearsal system (Baddeley, 1986). In repeating tasks, learners have to retain aural
input in their phonological store and keep it active in the phonological loop during thepauses before the input is reproduced, whereas shadowing tasks force learners to
immediately articulate the input overtly, such that they do not need to retain the input
in the phonological store (Miyake, 2009).
The second goal of this study was to examine whether processing accuracy
depends on the type of repeating (i.e., semantic, syntactic, or pragmatic). Table 6 showsthat RE3 has the lowest accuracy score. RE3 places the cognitive load on syntactic
processing by directing participants’ attention to a grammaticality judgment task. In
addition, processing accuracy in RE4 was significantly lower than in RE2. These
results suggest that for Japanese EFL learners, syntactic processing is the mostcognitively demanding attentional aspect, followed by pragmatic processing and thensemantic processing. This result is also in line with Nakanishi’s (2016) shadowing
study.
Analyzing repeating and shadowing data together using a 2 (task) × 4 (type)
ANOVA analysis revealed that there were significant main effects of type (F(2,210) =156.860, p <.01, partial η2 = .606), but neither a significant main effect of task
(F(1,210) =1.072, ns., partial η2 = .005) nor a significant interaction between task andtype (F(2,210) = .066, ns., partial η2 = .001). The multiple comparison analysis
revealed that the type 3 scores were significantly lower than those of types 2 and 4 (p< .01), that type 4 scores were significantly lower than those of type 2 (p < .01), andNAKANISHI, Hiroshi

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that RE scores were significantly lower than SH scores (p < .01). This two-way ANOVA
analysis consistently revealed that syntactic processing places a heavier cognitive load
on working memory resources than do semantic and pragmatic processing, regardlessof practice type (i.e., shadowing or repeating).
The third goal of this study was to explore whether repeating performance (i.e.,
reproduction rates and accuracy scores) differs according to English proficiency. The
results show that the higher proficiency group performed significantly better than thelower proficiency group and that there was a significant correlation between overall
English proficiency scores and repeating performance.
Analyzing repeating and shadowing data together using a 2 (proficiency) × 2(task) × 4 (type) ANOVA showed that there were significant main effects of proficiency
and type (F(1,210)=16.218, p < .01, partial η2 = .076, F(2,210) = 165.909, p <. 01,
partial η2 = .626, respectively). However, there were no significant interactions among
those variances (F(2, 210) = .534, ns., partial η2 = .005).
These analyses consistently show that Japanese EFL learners with higher
proficiency could employ English sound perception and each type of processing very
effectively.
Table 6 Summary of this study’s repeating data and Nakanishi’s (2016) shadowing data
Task

Main processing
aspect――Translation verification

Semantic

Grammaticality judgment

Syntactic

Pragmatic judgment

Pragmatic

SH/RE
SH1
RE1
SH2
RE2
SH3
RE3
SH4
RE4

Reproduction
rates
93.77
73.72

Accuracy scores
―

92.77

92.13

73.91

89.81

90.85

54.13

67.10

56.06

90.00

76.44

70.70

77.31

Notes. Mark range: 0–100. *The maximum processing accuracy score for SH/RE 2, 3, and 4 is 16.
However, for ease of comparison with the reproduction rate, the processing accuracy score isgraded based on a score of 100.

7. Conclusion
This study explored whether repeating performance (i.e., successfully reproducedrate) depends upon Japanese EFL learners’ attention to various aspects of processing(i.e., semantic, syntactic, or pragmatic) by imposing a second processing task (i.e., atranslation-verification, grammaticality judgment, or pragmatic judgment task) andThe Effect of the Attentional Aspect of Language Processing on Sound Perception in
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whether the results are different from the shadowing results of Nakanishi’s (2016)
study. The main outcome demonstrated that the accuracy scores in the syntactic
processing task during shadowing and repeating were the lowest. In addition,
successful repetition rates declined when attention was directed toward syntactic
aspects during shadowing and repeating, compared to the rates when attention was
primarily directed to phonological aspects. The results suggest that the cognitive loadof syntactic processing is resource consuming, leading to the bankruptcy of working
memory resources needed for sound perception.
Future studies should focus on aspects of prosody (i.e., pitch, intensity, andduration) in shadowing or repeating performance and explore the relationship between
learners’ attentional aspects (i.e., semantic, syntactic, or pragmatic) and prosody
aspects, because doing so would contribute to further investigations of cognitive
processes in L2 shadowing and repeating.
Acknowledgement
This study was partially supported by JSPS Grant-in-Aid for Scientific Research(C), (PI: Hiroshi Nakanishi, No.16K02928).
References
Baddeley, A. D. (1986). Working memory. New York, NY: Oxford University Press.
Geva, E., & Ryan, E. B. (1993). Linguistic and cognitive correlates of academic skills infirst and second languages. Language Learning, 43(1), 5-42.
Hahne, A., & Friederici, A. D. (2001). Processing a second language: Late learners'
comprehension mechanisms as revealed by event-related brain potentials.

Bilingualism: Language and Cognition, 4, 123-141.
Just, M. A., & Carpenter, P. A. (1992). Individual differences in working memory.

Psychological Review, 99, 122-149.
Kadota, S. (2007). Science of shadowing and reading aloud. [Shadowing to ondoku nokagaku]. Tokyo: Cosmopier Publishers.
Leeser, M. J., Brandl, A., & Weissglass, C. (2011). Task effects in second language
sentence processing research. In P. Trofimovich, & K. McDonough (Eds.), Applying

Priming Methods to L2 Learning, Teaching and Research: Insights from
Psycholinguistics. pp. 179-198. Amsterdam: John Benjamins Publishing Company.
Miyake, A., & Friedman, N. P. (1998). Individual differences in second language
proficiency: Working memory as language aptitude. In A. F. Healy and L. E.
Bourne, Jr. (Eds.), Foreign language learning, (pp. 339-364). Lawrence Erlbaum
Association.
Miyake, S., (2009) Nihonjin eigogakushûsha-no hukushô-niokeru saiseiritsu-to12

NAKANISHI, Hiroshi

hatsuwa sokudo-no henka-no kôsatsu [An analysis on reproducing rate and speechrate in the repetition task by Japanese learners of English]”, Kotoba-no Kagaku

kenkyû [Journal of the Japan Society for Speech Sciences], 10, 51-69.
Nakanishi, H., & Yokokawa, H. (2011). Determinant Processing Factors of Recall
Performance in Reading Span Tests: An Empirical Study of Japanese EFL
Learners. JACET Journal, 53, 93-108.
Nakanishi, H. (2016). The Effect of Contents Shadowing on English Sound Perception
for Japanese EFL Learners, The JACEC BULLETIN, 25, 33-44.
Yokokawa, H. (Ed.). (2006). Nihonjin eigo gakushusha no eitango shinmitsudo moji

hen: Kyoiku kenkyu no tameno dainigengo database [Familiarity of English words
for Japanese EFL learners, script version: The database for second language
education and research]. Tokyo: Kuroshio Publishers.