1. 2.3 Markedness Differential Hypothesis (MDH)
Eckman (1981) proposed the Markedness Difference Hypotheses (MDH), which groups the phonemes into marked or unmarked ones.
－ Unmarked sounds exist in most languages
around the world, like /p/, /d/, /a/,and /i/.
－ Marked sounds do not exist in most languages
such as the voice contrast stop coda, /ʒ /,/θ/, and /ð/.
For L2 learners, it is generally effortless to acquire unmarked sounds, while the more marked a phoneme is, the more difficult it is to pronounce it without an accent.

2. 2.5 The predictions of each SLA theory
If CAH is supported, /θ/, /ð/, and /ʒ / should be more difficult to acquire than /tʃ /,/dʒ / and /ʃ /.
－According to CAH, new sounds are difficult to acquire.
If SLM is supported, /tʃ /, /dʒ / and /ʃ / should be more difficult to master than /ʒ /,/θ/,/ð/.
－ According to SLM, new phonemes are difficult to acquire but easy to master. In contrast, similar phonemes are easy to acquire but difficult to master.
If MDH is supported, the difficulty level of the following phonemes should be /ʒ /> {/θ/ and /ð/}>{/tʃ /, /dʒ / and /ʃ /}.
－ According to MDH, this order is consistent with the markedness level.

3. 2.5 SLA theory: Three main theories about second language pronunciation acquisition.
Similar phonemes:
New sounds:
The comparison of L1 and L2 is not sufficient
The relative degree of difficulty should not only focus on L1 and L2, but also on the universal languages.
Marked sounds:
1. CAH
Identical phonemes:
Similar phonemes:
New sounds:
SLA theory
3.MDH
2. SLM
more difficult to master
EX. /ʒ /
Unmarked sounds:
easier to acquire

4. 2.5 The predictions of each SLA theory?
/ʒ /
CAH
/ʃ /
Taiwanese
SLA
learners
/θ/
SLM
/dʒ /
/ð/
MDH
/tʃ /

5. 3.5 Research question and hypotheses
Chapter 3 Methodology
3.5 Research question and hypotheses
3.1 Participants
3.2 Material
3.3 Measurement
3.4 Research design .

6. Chapter 3 Methodology
If a linguist wants to know whether L2 learners produce fricatives like L2 native speakers, he or she will inspect the peak of fricative frequency and the CV transient.
This thesis aims to figure out the authentic SLA situation pronunciation acquisition in Taiwan, and few researchers have undertaken the acoustic analysis of fricatives and affricates.
More specifically, the peak of fricative frequency and the CV transient of the six phonemes, /ʒ /,/θ/,/ð/,/tʃ /, /dʒ / and /ʃ /, are evaluated to better understand the Taiwanese SLA.

7. 3.1 Participants
The thirty-six participants are divided into four groups based on their age and mother tongues.
Group2
Group1
10 Junior high school students (age 13)
6 English native speakers(age 21)
36 male
Group4
Group3
10 University students (age21)
10 Senior high school students (age 17)

8. 3.1 Participants
Flege (1992) examined the perception and production of a novel second language, and found that an additional four years of English learning experience did not lead to any significant difference.
－One of the hypotheses in this study is that an additional four years of English learning experience in a non-English spoken country does not improve the speaker’s English pronunciation.

9. 3.1 Participants
Few researchers have investigated the efficacy of having an extra eight years of L2 learning in a non-L2 country.
－The second hypothesis of this paper is that an additional eight years of English learning experience in a non-L2 spoken country can improve L2 learners’ pronunciation.

10. 3.2 Material
The focus of this paper is to examine how the four groups pronounce the following six phonemes, /ʒ /,/θ/,/ð/,/tʃ /, /dʒ /, and /ʃ /.
These six sounds are useful for comparing the contrastive analysis hypotheses (CAH), the speech learning model(SLM), and the markedness differential hypothesis (MDH).
The six phonemes are distributed in different positions in eighty-eight selected English words.

11. Examples of the words analyzed in this study

12. Assistance of spectrogram
3.3 Measurement
Linguists use two ways to measure the correctness
of fricative pronunciation (Chung, 2009).
LPC
CV transient
Examine noisy turbulence
Assistance of spectrogram
Comparing the peak of fricative frequency to obtain the locations of the four groups’ tips of the tongue in the production of these six sounds.
Observing the F2 of the CV transient, since F2 is also related to the front or rear location of the tip of the tongue.

13. 3.3.1 LPC
Noisy turbulence is influenced by the distance between the tip of the tongue and the lips (Chung, 2009).
The greater the peak of the fricative frequency (LPC), the more to the front the tip of the speaker’s, while the reverse is true the smaller the peak of the fricative frequency (LPC) is.

14. 3.3.1 LPC
After recording the sounds, the PRAAT software is used to measure the location of tongue in the form of an LPC number.
The SPSS the statistical software is then used to identify whether or not the three Taiwanese groups differ significantly from the English native speaker group.
In this study, independent samples t-tests are applied to know whether or not these groups perform with significant differences.

15. Sample of LPC

16. 3.3.2 CV transient(supplementary data)
With CV transient, formants one and two are observed.
－Formant one (F1) shows the height of tongue. The smaller the number F1 is, the higher the tongue is.
－Formant two (F2) is related to a front or rear location of the tip of the tongue. The bigger F2 is, the more to the front the tongue is.  
This paper only needs the F2 data because both it and LPC are related to the front or back location of the tip of the tongue.

17. 3.3.2 CV transient(supplementary data)
Only vowels and sonorants have formants, and neighboring consonants can influence the formants of vowels.
With the assistance of the CV transient, the locational relationship between the six sounds and vowels can also be known.
The CV transient cannot be calculated using SPSS to know whether Taiwanese students differ significantly from English native speakers.

18. Sample of CV transient

19. 3.4 Research design

21. 3.5 Research question and hypotheses
RQ1 H1 H2
An additional four years of English learning experience in a non-English spoken country does not improve English learners’ pronunciation.
An additional eight more years of English learning experience in a non-English spoken country are effective in improving English learners’ pronunciation.
The research question examines which SLA theory can best explain the acquisition of English pronunciation in Taiwan.

22. Chapter Four: Results and Analysis

23. RQ1 ： The predictions of each SLA theory?
/ʒ /
CAH
/ʃ /
Taiwanese
/θ/
SLM
/dʒ /
/ð/
MDH
/tʃ /

24. 4.1 /ʒ/,/θ/,/ð/,/tʃ/, /dʒ/, and /ʃ/ as the coda
4.1.1 Group 2 vs. Group 1
Table 4.1. Group statistics of LPC for Group Two and Group One (as the coda)

25. 4.1 /ʒ/,/θ/,/ð/,/tʃ/, /dʒ/, and /ʃ/ as the coda
4.1.1 Group 2 vs. Group 1(English Native Speaker)
＊ The order of the tip of the tongue from front to rear of Group One is {/θ/ (5532), /ð/(4998)}> {/tʃ /(3234), /dʒ /(3203), /ʃ /(3090), /ʒ /(2922)}.
＊ The order of the tip of the tongue from front to rear of Group Two is {/θ/ (5601), /ð/(5450)}>/ʃ /(4050), >
{/dʒ /(3580), /ʒ/(3536)/tʃ /(3487)}.
－Only /ʃ/ is pronounced significantly differently, and the p value is .000.
－Only in the production of /ʃ/ do Taiwanese junior high school students differ from American native speakers.

26. 4.1 /ʒ/,/θ/,/ð/,/tʃ/, /dʒ/, and /ʃ/ as the coda
4.1.2 Group 3 vs. Group 1
Table 4.2. Group statistics of LPC for Group Three and Group One (as the coda)

27. 4.1 /ʒ/,/θ/,/ð/,/tʃ/, /dʒ/, and /ʃ/ as the coda
4.1.2 Group 3 vs. Group 1(English Native Speaker)
＊ The order of the tip of the tongue from front to rear of Group One is {/θ/ (5532), /ð/(4998)}> {/tʃ /(3234), /dʒ /(3203), /ʃ /(3090), /ʒ /(2922)}.
＊ The order of the tip of the tongue from front to rear of Group Three is {/θ/ (5367), /ð/(5348)} >
{/tʃ /(4130), /ʃ /(4050), /dʒ /(3826), /ʒ/(3658)}.
－Only /tʃ / ( is pronounced significantly differently, and the p value is .006.
－ Senior high school participants produced /ʃ /, /tʃ / and /dʒ / with more difficulty than /θ/ and /ð/.

28. 4.1 /ʒ/,/θ/,/ð/,/tʃ/, /dʒ/, and /ʃ/ as the coda
4.1.3 Group 4 vs. Group 1
Table 4.3. Group statistics of LPC for Group Four and Group One (as the coda)