Chapter 3 Methodology
3.2 Data Analysis
3.2.3 Model Construction
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utilized in our study. A general discussion of the application of these models will be revealed in Chapter Six.
3.2.3 Model Construction
A pilot study was conducted before our research, and we found several items of evidence of asymmetry and symmetry between vowel perception and production. We will then follow convention and carry out error analyses on the participants’
performance in the four experiments. Then, we will give possible explanations for the errors and see if they meet our hypothesis mentioned in Section 2.4.2. Further discussion will be made if there are any discrepancies among our hypotheses and results that we collect.
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Chapter 4
Results and Findings
In this section, we will present the results of four experiments. All of the results of the participants from all of the three levels of Taiwan Mandarin EFL learners and a group of American English native speakers are included. In order to answer our research questions, we will present the statistical analyses of the vowel formant structures and the results of the perception tasks. We first analyzed all of the F1 and F2 values collected in Experiments I and II for English and Mandarin vowels, respectively. The formant structures and vowel grids will be described in Section 4.1. Experiments Three and Four present the participants’ perception of English vowels, and the results will be shown in Section 4.2. A brief introductory table of the language background of the participants is shown in Appendix IV. A couples of examples of the spectrogram created from the recordings of our speakers are given in Appendix III.
4.1 Production Performance
This section presents the vowels produced by the Taiwan Mandarin speaker participants. The English vowels produced by the Taiwan Mandarin EFL learners are given in 4.1.1, and Mandarin vowels produced by Taiwan Mandarin speakers are given in 4.1.2. English Vowels produced by American English native speakers are given in 4.1.3.
In this section, the elementary female learners are categorized as a group and named using the abbreviation EF; the elementary male learners are named EM; the intermediate male learners, IM; the intermediate female learners, IF; the high-intermediate male learners, HM; the high-high-intermediate female learners, HF; and the
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male and female native speakers, NM and NF, in order to make the charts and description more concise.
4.1.1 English Vowels Produced by Taiwan Mandarin EFL Learners
The F1 and F2 values of the English vowels produced by all of the levels of the Taiwan Mandarin EFL learners are listed in Table 4-1, which shows the F1 and F2 values. Table 4-2 shows six vowel grids from (a) to (f), each one for a different gender at a different level. Table 4-3 to Table 4-5 display schematic spectrograms showing the F1 and F2 of each English vowel as produced by the different levels of both genders of speakers. A brief explanation of each table is given after each table. An overall description of the tables and schematic spectrograms will be will be placed after the Tables. 4.1.1.1 deals with results for the elementary learners, 4.1.1.2 the intermediate levels and 4.1.1.3 with the high-intermediate levels.
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Table 4- 1 Formant Structures of English Vowels produced by Taiwan EFL Learners
F1SDF2SDF1SDF2SDF1SDF2SDF1SDF2SDF1SDF2SDF1SDF2SD heed[i]301.2926.002146.95151.27322.7927.902495.1033.87331.8618.822278.70182.53393.2940.522992.1754.44301.4336.062281.66119.70369.9735.972540.55723.66 hid[ɪ]266.55112.291801.71750.80325.460.002585.020.00333.600.002056.850.00418.7439.382640.84638.24323.6344.252200.26101.22381.1236.922814.85102.49 head[ɛ]448.69206.091636.91681.34456.790.002345.300.00499.8843.092091.20254.10865.18117.902169.44126.50426.20102.242101.23244.26675.3196.702201.49456.44 hayed/hade[e]478.4569.291942.61182.91400.741.132486.1533.17446.0446.432148.62304.36564.26162.362301.84483.48384.3637.562203.28158.65518.42100.792651.59125.62 had[æ]540.4494.361816.8495.69428.2341.601938.40356.11601.03131.211919.52374.98833.2490.142216.8427.67652.88169.651827.59202.17758.88191.112210.76452.21 heard[ɝ]462.4532.981597.3577.03389.090.002053.190.00411.910.001385.350.00503.8366.111873.59157.86445.9332.331417.4186.86583.4862.181709.53111.90 hod[ɑ]432.89291.80779.91503.22661.65268.991113.83169.56746.11184.531043.97239.43914.5369.611395.0037.50729.7277.911164.98122.66836.3930.911276.2237.82 hawed[ɔ]377.15256.72711.26463.31466.6854.15801.6020.53454.1566.69802.5621.49596.90119.521075.78173.19459.0166.201125.48568.81603.326.62959.66102.26 hoed[o]412.45177.01767.16326.27451.9925.99902.7795.23437.8440.14889.7482.20467.5631.13837.6441.81464.4482.11806.2291.43544.4957.281038.89237.03 hood[ʊ]335.8236.63902.21119.31429.220.001223.100.00311.720.001173.030.00417.8413.45990.1039.90349.4525.281034.40115.02405.2522.75973.39139.65 who’d[u]334.7920.54946.0458.44373.7924.531209.50235.73344.065.191063.5089.73387.0255.96818.46134.97335.3427.61910.03123.62396.7230.31910.2886.75 hudd[ʌ]332.04238.99795.11512.09557.6860.681244.807.80519.5698.801261.689.09784.39103.961550.3967.79620.85141.941254.68109.03543.8980.471394.9859.31
MFMF
HI Test wordTargetFM
IntermediateELEMENTARY Note: This table illustrates the formant values of the vowels produced by all three levels of Taiwan EFL learners. The first two columns are the test words and target phonemes. The following columns are respectively the mean values (arithmetic average) and standard deviation (SD) measured in the first and second words the speakers uttered. The values contain F1 and F2 of each phoneme and their SD right next to them. The first section on the left is the elementary level male (M) speakers and female (F) speakers, Intermediate level is in the middle, and the high intermediate on the right.
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Figure 4-1 Vowel Grids of English produced by Taiwan EFL Learners
[i] [ɪ]
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Note: The above six charts respectively show the vowel grids for the three different levels of the Taiwan EFL learner, respectively. The first three (a) to (c) are male learners, and (d) to (f) are those of female learners. Figure 4-1 (a) showsvowel grids of the male participants at the elementary level, (b) the intermediate level, and (c) the high-intermediate level, so as (d) to (f). The grids are made up of the relative space of the tongue height and tongue advancement.
The vertical axis shows the F2 values, and the horizontal axis the F1 values. The dots on the chart represent the space of the vowel. The brackets explain the dots on their left with the phonemes in them, and some of the vowels are so close that an indicator was employed to specify their relationship.
4.1.1.1 Elementary Level of Taiwan Mandarin EFL Learners
In our results derived from the data of the elementary level participants in this study, the vowels are classified into high, mid and low for the vertical view and front and back for the horizontal view. There are, thereafter, high-front, mid-front, low-front, high-back, mid-back and low-back vowels.
The male speakers and the female speakers show a different pattern here. First, the English vowels produced by the male speakers lack mid-central and low-back features.
Their [i] and [ɪ] are classified as high-front, their [ɝ], [ɛ] and [e] as mid-front, and their [æ] as low-front. The back vowels are [u], [ʊ], [o], [ɔ], [ɑ] and [ʌ], where [u], [ʊ] and [ʌ] are high vowels, and [o], [ɔ] and [ɑ] are mid-vowels. Note, therefore, that there is no distinct mid-central or low-back vowel here.
The female speaker, on the other hand, made four different kinds of vowel positions. Their [i] and [ɪ] are classified as high-front, where [i] and [ɪ] are very close and [i] is slightly higher than [ɪ]. [ɝ], [ɛ] and [e] and [æ] are classified as mid-front, where [e] is higher than [ɛ] but both are more advanced than [ɝ] and [æ]. The back vowels are [u], [ʊ], [o], [ɔ], [ɑ] and [ʌ], where [u] and [ʊ] are high vowels, [o] and [ɔ]
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are mid-vowels, and [ʌ] and [ɑ] are low vowels. The vowel [ɑ] is relatively lower than all of the others. Note, therefore, that there is no distinct mid-central or low-front vowel here. A schematic spectrogram is illustrated in Figure 4-2 with the verbs that show a somewhat distinct pattern and are as follows.
Figure 4-2 Schematic Spectrograms of Vowels Produced by Elementary Taiwan EFL Learners
Note: Figure 4-2 (a) and (b) show the schematic spectrograms of the F1 and F2 of the English vowesl produced by the male and female elementary levels of the Taiwan Mandarin EFL learners, respectively. The lower line represents the F1 of the vowel, while the higher line stands for the F2.
[i] [ɪ] [ɛ] [e] [æ ] [ɝ] [ɑ] [ɔ] [o] [ʊ] [u] [ʌ]
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4.1.1.2 Intermediate Level of Taiwan Mandarin EFL Learners
For the intermediate level participants, the classification of the vowels also consists of high, mid and low for tongue height and front, central and back for tongue advancement. In general, the vowels [i] and [ɪ] can be classified as high-front, [ɛ] and [e] as mid-front, and [æ] as low-front. The mid-central vowel is represented by [ɝ] and [ʌ]. The back vowels are [u], [ʊ], [o], [ɔ] and [ɑ], where [u], [ʊ] are high vowels, [o], [ɔ] are mid vowels, and [ɑ] is a low vowel. However, the [ɛ] produced by the female learners are very similar to their [æ]. The schematic spectrograms are also provided below as Figure 4-3 to yield a clearer view.
Figure 4-3 Schematic Spectrogram of Vowels Produced by Intermediate Taiwan EFL Learners
[i] [ɪ] [ɛ] [e] [æ ] [ɝ] [ɑ] [ɔ] [o] [ʊ] [u] [ʌ]
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MM-F1 MM-F2
( a)
(a)
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Note: Figure 4-3 (a) and (b) show the schematic spectrogram of the F1 and F2 of each English vowel produced by the male and female intermediate levels of the Taiwan Mandarin EFL learners, respectively. The lower line represents the F1 of the vowel, while the higher line represents the F2.
4.1.1.3 High-Intermediate Level of Taiwan Mandarin EFL Learners
Among the high-intermediate level participants, for male learners, vowels [i] and [ɪ] are classified as high-front, [ɛ] and [e] as front, and [æ] as low-front. The mid-central vowel is represented by [ɝ] and [ʌ], where [ʌ] is lower than [ɝ]. The back vowels are [u], [ʊ], [o], [ɔ], [ɑ], where [u], [ʊ] are high vowels, [o], [ɔ] are mid-vowels and [ɑ] is a low vowel. The [o] and [ɔ] are at a similar height and differ in advancement.
The values produced by the female learners, on the other hand, are not identical with those of male learners. Female learners show a lower [ɛ] which is somewhat higher than [æ]. The vowels [u] and [ʊ] are not much differentiable from each other. Also, their [o] and [ɔ] are in the same horizontal space, but different heights. To give a better view, schematic spectrograms are shown in Figure 4-4 as follows.
[i] [ɪ] [ɛ] [e] [æ ] [ɝ] [ɑ] [ɔ] [o] [ʊ] [u] [ʌ]
0 500 1000 1500 2000 2500 3000 3500
MF-F1 MF-F2
(b)
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Figure 4-4 Schematic Spectrogram of Vowels Produced by High Intermediate Taiwan EFL Learners
Note: Figure 4-4 (a) and (b) show the schematic spectrogram showing of the F1 and F2 of each English vowel produced by the male and female intermediate levels of the Taiwan Mandarin EFL learners, respectively. The lower line represents the F1 of the vowel, while the higher line represents the F2.
4.1.1.4 General Findings
The pair [i]-[ɪ] share very similar F1 values among the six different non-native groups.
The vowels [ɛ]-[e]-[æ], [u]-[ʊ], [o]-[ɔ]-[ɑ] and [ʌ] on the other hand, showed a progress from one level to another. The similarities in the pairs between [ɛ]-[e]-[æ], [u]-[ʊ] and
[i] [ɪ] [ɛ] [e] [æ ] [ɝ] [ɑ] [ɔ] [o] [ʊ] [u] [ʌ]
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[o]-[ɔ]-[ɑ] made by the elementary levels were relatively distinguished.
In the case of the elementary level participants, the F1 values of [ɛ]-[e]-[æ] are quite similar. When we attend to the male group only, we find that their [e] and [ɛ] are nearly the same, and their [æ], while at a different height, is still very close to the two phonemes. Female groups, on the other hand, had a similar problem to that of the male group. They pronounced [æ] at a mid-central position, and [e]- [ɛ] were different in height. When we take a look at the performance of the female intermediate group, we may be surprised that they enlarged the space from [e] to [æ]. When participants made [æ] to a front-low position, the position of [ɛ] was also dragged down at the same time.
In case of the high-intermediate levels, both genders successfully distinguished the three vowels from each other.
The production of vowel pair [u]-[ʊ] is another interesting issue. We found that the participants of both genders in the elementary level tended to categorize the F2 values (tongue advancement) into the same slot, as, as we have stated in the previous chapter, elementary learners make no distinction between mid-central or low vowels. When we move on to the next levels, we find the male group has separated the two vowels and that the phonemes remained on to the high-intermediate group. The female groups, on the other hand, have made a difference on them in the middle, but failed to do so at the high-intermediate level.
The female participants showed a good distinction between [o]-[ɔ]-[ɑ] at the elementary level, and the distinctness became clearer as their proficiency went up. The male participants, however, failed to do so at the very beginning, for [o] and [ɑ] were not differentiated at the elementary levels actually. The distinction was later constructed
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at the intermediate level, while the concept of [ɔ] did not accord with that of the female group. The female group consistently uttered [o] at a relatively higher space than [ɔ].
As for the vowel [ɑ], both groups, at first, produced a much further back [ɑ] than that of their next level of proficiency.
Last, but not the least, the vowel [ʌ] has been shifted from the position of a back vowel to central one. The male participants tended to make it a rather high and back vowel, but a mid and central one afterwards. The female learners, yet, from low back to mid central.
Figure 4-5 English Vowel Grid of Male Speakers
Note: The table is retrieved from the same as Figure 4-5. The difference is that we combine all male data from four levels participants, and were marked as different labels.
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Figure 4-6 English Vowel Grid of Female Speakers
Note: The table is retrieved from the same as Figure 4-1. The difference is that we combine all female data from four levels participants, and were marked as different labels.
The previous two tables, Figure 4-5 and Figure 4-6 illustrate the vowel grid among all of the levels of the participants, including the native speakers.
4.1.2 Mandarin Vowels Produced by Taiwan Mandarin EFL Learners
The Mandarin vowels produced by the TM EFL learners will be described in this section. The overall values of all the F1 results and F2 results of the vowels produced by all of the levels of the participants will be illustrated in Table 4-2. We provide the vowel grids and the schematic spectrograms below in Figure 4-7 to Figure 4-13 for both genders at each level and the overall average of all levels of each gender. Figure 4-7 includes eight charts where all genders and levels are covered, each being drawn into an individual chart. Figure 4-8 to Figure 4-11 are eight schematic spectrograms showing the F1 and F2 of each Mandarin vowel produced by the Taiwan Mandarin EFL learners.
Figure 4-12 and Figure 4-13 show the vowel grids of the Mandarin vowels produced
[i]
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by both genders of Taiwan Mandarin speakers where all the data of all levels of speakers were integrated together.
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Table 4-2 Formant Structures of Mandarin Vowels Produced by Taiwan EFL Speakers
F1SDF2SDF1SDF2SDF1SDF2SDF1SDF2SD [a]774.5479.341202.74120.791060.7881.951560.1954.70762.9274.561181.7894.341088.0283.831551.6064.61 [ɑ]739.0292.531422.0893.08948.44104.061587.69207.91726.0379.041381.7387.07995.70118.241628.73212.98 [ə]518.7339.871337.1062.09633.7786.941497.2990.71500.1265.631353.0877.65620.51111.771519.6698.36 [ɚ]492.9656.681298.41101.19610.37103.411548.89122.16482.8741.811288.89105.30586.1684.341498.57162.68 [ɛ]417.1043.282002.2670.59568.6750.882001.01453.27411.0839.902027.54139.58546.1884.551925.79476.44 [ɤ]477.6940.011236.4723.41668.5395.111305.2179.85479.4740.251235.1041.61663.7994.051350.3884.36 [i]279.9730.862235.9190.53371.6251.922832.4367.20275.8633.902241.13135.18372.7949.952831.37186.74 [o]502.0330.19829.39116.30562.7465.06881.8667.27525.2559.04988.04454.04586.2071.771006.44156.71 [u]367.9517.28628.1371.27433.4419.54785.14177.67352.7129.41614.8486.43443.4228.12874.09219.59 [y]308.0827.661929.53127.69386.5126.972170.3353.49292.4524.421925.2090.87399.8846.042139.80107.10
Test phonemeHigh IntermediateALL MFMF F1SDF2SDF1SDF2SDF1SDF2SDF1SDF2SD [a]745.2558.681172.9666.301107.8634.251445.5634.25795.7492.831160.2892.751129.1583.891582.2927.81 [ɑ]722.3466.511344.1977.011037.259.601612.389.60706.4977.411412.2826.841041.67129.931687.21240.05 [ə]476.3777.451379.6387.07547.8065.671583.9565.67536.7131.631300.0911.13605.18150.841506.1191.28 [ɚ]483.2029.891268.27114.35491.170.811312.130.81456.4911.321337.2546.83585.8029.481497.98184.49 [ɛ]403.7541.612040.01170.76430.9121.152516.5221.15421.683.552047.11139.05547.56109.461638.90370.26 [ɤ]485.2039.031221.1347.75530.2462.211232.0562.21463.8740.501280.593.69681.2597.431430.2414.88 [i]269.6435.772247.75162.91316.1985.172719.7585.17287.3829.642231.00119.24364.8452.172908.81249.63 [o]540.4270.291124.94602.90511.3135.93887.6735.93530.1951.49905.5441.36630.4669.951184.3481.86 [u]336.1528.81604.9280.43356.7564.73617.8064.73372.5921.60616.30127.15464.0429.691052.84182.05 [y]280.5217.701923.6769.14324.8848.972000.2648.97295.137.201919.7414.83426.3959.292165.10108.71
Test phonemeELEMENTARYIntermediate MFMF Note: This table illustrates the formant values of the Mandarin vowels produced by all three levels of Taiwan EFL learners. The first two columns are the test words and target phonemes. The following columns are respectively the mean values (arithmetic average) and standard deviation (SD) measured in the first and second words the speakers uttered. The values contain F1 and F2 of each phoneme and their SD right next to them. The first section on the left is the elementary level male (M) speakers and female (F) speakers, Intermediate level is in the middle, and the high intermediate on the right.
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Figure 4-7 Vowel Grids of Mandarin Monophthongs Produced by All Taiwan EFL Learners
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Note: The above eight charts respectively show the vowel grid of the three different levels of the Taiwan EFL learners and two of the overall average of each gender. The first two (a) and (b) are male and female elementary level learners, (c)and (d) the intermediate level learners, and (e) and (f) the high-intermediate level learners. The overall average performance of both genders are shown in (g) and (h), male and female in order. The grids are made up into the relative space of the tongue height and tongue advancement. The vertical axis goes with F2 values, and the horizontal axis with F1 values. The dots on the chart represent the space of the vowel. The brackets explain the dots on their left with the phonemes in them, and some of the vowels are too close so that an indicator was employed to specify their relationship.
[i] [y]
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In the case of Mandarin vowels, the nine different grids, which are from high to low and front to back, are still employed. What is noteworthy here is that in this task, all participants were native speakers, their vowel patterns only have a very slight difference, which will be discussed in chapter five. Since all groups present a roughly similar pattern, we may give a thorough description here, instead of a detailed one for each group.
The Mandarin vowels comprise high, mid and low and front, central and back vowels and our target vowels could be classified into high-front, mid-front, mid-central, mid-low and high-back.
The vowels [i] and [y] are classified as high-front, and [ɛ] as front. The mid-central vowels are represented by [ə], [ɚ] and [ɤ]. The mid-low vowels are [ɑ] and [a].
The back vowels are [u] and [o], where [u] is a high vowel, and [o] is a mid-vowel. To give a better view, the schematic spectrograms are as follows.
Figure 4-8 Schematic Spectrogram of Mandarin Monophthongs Produced by Elementary Taiwan Mandarin EFL Learners
[i] [y] [ɛ] [ə] [ɚ] [ɤ] [o] [a] [u] [ɑ]
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EM-F1 EM-F2
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Note: Figure 4-8 shows the schematic spectrogram of the F1 and F2 of each Mandarin vowel produced by the speakers, where (a) is male and (b) is female. The lower line represents the F1 of the vowel, while the higher line represents the F2.
Figure 4-9 Schematic Spectrogram of Mandarin Monophthongs Produced by Intermediate Taiwan Mandarin EFL Learners
[i] [y] [ɛ] [ə] [ɚ] [ɤ] [o] [a] [u] [ɑ]
0 500 1000 1500 2000 2500 3000
EF-F1 EF-F2
[i] [y] [ɛ] [ə] [ɚ] [ɤ] [o] [a] [u] [ɑ]
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IM-F1 IM-F2
(b)
(a)
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Note: Figure 4-9 shows the schematic spectrogram of the F1 and F2 of each Mandarin vowel produced by the speakers, where (a) is male and (b) is female. The lower line represents the F1 of the vowel, while the higher line represents the F2.
Figure 4-10 Schematic Spectrogram of Mandarin Monophthongs Produced by High Intermediate Taiwan Mandarin EFL Learners
[i] [y] [ɛ] [ə] [ɚ] [ɤ] [o] [a] [u] [ɑ]
0 500 1000 1500 2000 2500 3000 3500
IF-F1 IF-F2
[i] [y] [ɛ] [ə] [ɚ] [ɤ] [o] [a] [u] [ɑ]
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HM-F1 HM-F2
(b)
(a)
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Note: Figure 4-10 shows the schematic spectrogram of the F1 and F2 of each Mandarin vowel produced by the speakers, where (a) is male and (b) is female. The lower line represents the F1 of the vowel, while the higher line represents the F2.
Figure 4-11 Schematic Spectrogram of Mandarin Monophthongs Produced by All Taiwan Mandarin EFL Learners
[i] [y] [ɛ] [ə] [ɚ] [ɤ] [o] [a] [u] [ɑ]
0 500 1000 1500 2000 2500 3000
HF-F1 HF-F2
[i] [y] [ɛ] [ə] [ɚ] [ɤ] [o] [a] [u] [ɑ]
0 500 1000 1500 2000 2500
(b)
(a)
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Note: Figure 4-11 shows the schematic spectrogram of the F1 and F2 of each Mandarin vowel produced by the speakers, where (a) is male and (b) is female. The lower line represents the F1 of the vowel, while the higher line represents the F2.
The Mandarin vowels produced by the male learners showed relatively consistent results. We may see in Figure 4-12 that all of the male participants almost produced almost the same performance on the test items. Each vowel was distinct from the other.
[i] and [y] are high-front vowels, where [i] is slightly ahead of [y]. [ɛ] could be categorized as a front mid-vowel. [ɤ], [ɚ] and [ə] should be seen as mid-central vowels.
What is interesting here is that the performance of these three vowels was very close, and they did not vary from each other within the groups. The production of [a] and [ɑ], in male groups, differed in a slight difference in tongue height and advancement, where [a] is a bit lower and slightly more to the rear than [ɑ]. The back vowels, still, made a clear grid in [u] was very different from [o]. However, if we take a close look at the vowel [o], we find that the tongue advancement of [o] moved from a mid to a relatively back position from the elementary group to the high-intermediate group.
[i] [y] [ɛ] [ə] [ɚ] [ɤ] [o] [a] [u] [ɑ]
0 500 1000 1500 2000 2500
(b) 3000
‧
Figure 4-12 Vowel Grid Among All Levels of Male Participants
Note: The figure is created with data retrieved from Figure 4-7. The difference between the original figure and this one is that we have combined all of the data from the male participants at all four levels, and different groups were marked with different labels.
As we can see in Figure 4-13, the female participants, on the other hand, were more inconsistent in their production of the L1. The [a] and [ɑ] sound were very close and could only be differentiated by a slight difference in tongue height, where [ɑ] was a bit higher than [a].
‧
Figure 4-13 Vowel Grid Among All Levels of Female Participants
Note: The figure is retrieved from and is the same as Figure 4-7. The difference between the original figure and this one is that we have combined all of the data from the female participants at all four levels, and were marked as different labels.
The two figures above both give us a clearer insight when comparing all of the levels of the participants of both genders.
4.1.3 English Vowels Produced by American English Native Speakers
The F1 and F2 values of the English vowels produced by the American English native speakers are listed in Table 4-3. Figure 4-14 are two vowel grids are divided into (a) and (b), where (a) is for male and (b) for female. Figure 4-15 displays the schematic spectrograms showing the F1 and F2 of each English vowel produced by both genders of the American native speakers.
[i] [y]
‧
Note: This table illustrates the formant values of the English vowels produced by both genders of the American English native speakers. The first two columns show the test words and the target phonemes. The following columns are respectively the mean values (arithmetic average) and standard deviation (SD) measured in the first and second words that the speakers uttered, respectively. The values contain F1 and F2 of each phoneme and their SD is given to the right next to them. The first section on the left shows the results for the elementary level male (M) speakers and female (F) speakers, the results for the intermediate level are in the middle, and those for the high-intermediate level are the right.
( d)
( e)
‧
Figure 4-14 Vowel Grids of English Produced by American English Native Speakers
Note: The above two charts show the vowel grids of the male and female American English
native speakers, respectively. The grids are made up of the relative space of the tongue height
and tongue advancement. The vertical axis shows the F2 values, and the horizontal axis shows
the F1 values. The dots on the chart represent the space of the vowel. The brackets with the
phonemes in them explain the vowel next to the bracket, and some of the vowelsare too close
[i]
‧ 國
立 政 治 大 學
‧
N a tio na
l C h engchi U ni ve rs it y
together to be able to read them in the chart so an indicator is employed to specify their
relationship.
In regard to American English native speakers, both of the groups show a similar production pattern although there is still a small amount of differences. In case of the male American English native speakers, the vowels [i], [ɪ] and [e] are classified as
In regard to American English native speakers, both of the groups show a similar production pattern although there is still a small amount of differences. In case of the male American English native speakers, the vowels [i], [ɪ] and [e] are classified as