Vowel F2 Research Articles

Bunyi Forman Vokal dalam Bahasa Jawa Ngoko: Kajian Fonetik Akustik

The Javanese language (BJ) is divided into three, namely Ngoko, Krama Madya, and Krama Inggil. BJ consists of 10 vowel sounds: [i, I, e, ɛ, a, ǝ, o, ɔ, U, u]. This study aims to determine the values of BJ vowel sounds based on FORMAN data analysis, comparing the voices of male speakers (PL) and female speakers (PP). Additionally, the study aims to identify the more dominant vowel sounds based on gender. The qualitative method was used to collect data on the vowel sounds of Ngoko Javanese (BJN) by analyzing voice recordings using the Praat application program. The quantitative method was employed to calculate the FORMAN F1, F2, and F3 values and determine the average difference in BJN vowel sounds. Data from the BJ dictionary, consisting of 10 words with vowel sounds at the beginning, were used for analysis. The results showed that in PL, the highest vowel values were: [u] at 3089Hz, [i] at 3918Hz, [ɔ] at 3535Hz, and [ɛ] at 3228Hz. The lowest vowel values were: [ɛ] at 277Hz, [U] at 431Hz, and [i] at 336Hz. In PP, the highest vowel values were: [ɛ] at 3021Hz, [i] at 3200Hz, [I] at 3083Hz, and [o] at 3367Hz. The lowest vowel values were: [e] at 391Hz, [I] at 525Hz, [ɛ] at 385Hz, and [i] at 455Hz. In conclusion, BJN consists of 10 vowel sounds, with the highest vowel sound being [ɔ] and the lowest vowel sound being [i] in PL. The comparison of vowel sounds at the beginning of words in PL and PP in BJN, based on the high and low sounds of the F1, F2, and F3 vowel sounds, indicates that PL is more dominant.

Revisiting the sociophonetics of sexuality in spontaneous speech

This study surveys sociophonetic variation in sibilant and vowel production for 44 Bay Area English speakers. I focus on (i) whether sexual orientation is an independent predictor, or interacts with gender, and (ii) what the patterning of bi + (bisexual, pansexual, queer, etc.) and non-binary speakers adds to previous claims (e.g., Gaudio 1994, Pierrehumbert 2004, Willis 2023). All participants completed a Map Task in pairs; 37 participated in a sociolinguistic interview. Recordings were auto-transcribed, forced-aligned, and hand-checked. For /s ʃ z ʒ/, tokens under 0.05 sec, in /str/ clusters, and/or adjacent to another sibilant were excluded. Before getting COG and skew, 0.02 sec were subtracted from token edges and voicing was Hann band-filtered. For all vowels and sibilants, mean and midpoint f0 were taken, and F1-F4 for vowels (using the median of values at midpoint plus six surrounding timepoints). Results show sexual orientation alone is not a robust predictor of /s/ frontedness. Both gender and sexuality interacted with duration for /s/ frontedness and vowel f0; gender and sexuality also interacted to influence /ʃ/ frontedness and /z/ devoicing, as well as vowel space shape. These results imply that, when bi + and non-binary identities are incorporated, the phonetic indexation of sexual identity is not easily generalizable within orientation labels, at least for informal speech.

Protective face masks affect clearly produced diphthongs by L1 and L2 English talkers

The study investigated how the use of protective face masks and language experience shape the production of listener-oriented clear speech. One L1 and one L2 English talker read sentences in a clear and conversational speaking style with and without a surgical mask. Formant trajectories between the onset and offset of two diphthongs, /aɪ/ and /eɪ/, were analyzed using Euclidean distance in the F1–F2 vowel space. The results showed that the distance between the onset /a/ and the offset /ɪ/ was larger when speech was produced without the mask and when speaking clearly. These modifications were larger for L1 talker compared to the L2 talker. The Euclidian distance for /eɪ/was only affected by speaking style. The results suggest that talkers produced hyperarticulated diphthongs characterized by larger formant movements in clear speech. The presence of a mask limited jaw movement for the diphthong containing the low vowel. Additionally, the L1 talker made larger articulatory modifications in response to the presence of a mask and listener-oriented clear speech compared to the talker with less extensive experience with the target language. These production patterns may be related to lower word recognition in noise for masked, conversational, and L2 speech found in previous work.

Acoustics of Emphatics and Uvulars in Bedouin Hijazi Arabic

The current study examines the effects of emphatics /ðˤ sˤ tˤ/ and uvulars /ʁ χ/ on following vowels in Bedouin Hijazi Arabic. The main goal is to observe F1 and F2 of vowels /i æ u/ next to the aforementioned sounds. The outcome of this study shows that F1 and F2 values next to emphatics and uvulars are reliable acoustic correlates. Emphatics and uvulars next to vowels increase F1 values, a pattern not noticeable in vowels next to plain sounds /ð s t/. Both groups also show lower F2 values compared to plain coronals. The size of F2 decrease, however, is lower in vowels following emphatics than vowels following uvulars. Differences in F2 values between these sound groups suggest differences in their articulatory mechanisms.

Acoustics of Emphatics and Uvulars in Bedouin Hijazi Arabic

The current study examines the effects of emphatics /ðˤ sˤ tˤ/ and uvulars /ʁ χ/ on following vowels in Bedouin Hijazi Arabic. The main goal is to observe F1 and F2 of vowels /i æ u/ next to the aforementioned sounds. The outcome of this study shows that F1 and F2 values next to emphatics and uvulars are reliable acoustic correlates. Emphatics and uvulars next to vowels increase F1 values, a pattern not noticeable in vowels next to plain sounds /ð s t/. Both groups also show lower F2 values compared to plain coronals. The size of F2 decrease, however, is lower in vowels following emphatics than vowels following uvulars. Differences in F2 values between these sound groups suggest differences in their articulatory mechanisms.

Impact of 3-dimensional anatomical changes secondary to orthognathic surgery on voice resonance and articulatory function: a prospective study

An evaluation was made of the impact of orthognathic surgery (OS) on speech, addressing in particular the effects of skeletal and airway changes on voice resonance characteristics and articulatory function. A prospective study was carried out involving 29 consecutive patientssubjected to OS. Preoperative, and short and long-term postoperative evaluations were made of anatomical changes (skeletal and airway measurements), speech evolution (assessed objectively by acoustic analysis: fundamental frequency, local jitter, local shimmer of each vowel, and formants F1 and F2 of vowel /a/), and articulatory function (use of compensatory musculature, point of articulation, and speech intelligibility). These were also assessed subjectively by means of a visual analogue scale. Articulatory function after OS showed immediate improvement and had further progressed at one year of follow up. This improvement significantly correlated with the anatomical changes, and was also notably perceived by the patient. On the other hand, although a slight modification in vocal resonance was reported and seen to correlate with anatomical changes of the tongue, hyoid bone, and airway, it was not subjectively perceived by the patients. In conclusion, the results demonstrated that OS had beneficial effects on articulatory function and imperceptible subjective changes in a patient’s voice. Patients subjected to OS, apart from benefitting from improved articulatory function, should not be afraid that they will not recognise their voice after treatment.

An exploration of mixed race and the California Vowel Shift

The California Vowel Shift (CVS) has been the study of much acoustic linguistic inquiry since it was first noted in the 1980s. It has since been grouped in with other like patterns which have arisen independently under the name, Low-Back-Merger-Shift (LBMS), though California will be the focus of the present study. The current study builds on previous literature by investigating acoustic vowel quality within a neighborhood in San Francisco, while also working to fill the gap of studies which take into account and specifically highlight mixed race peoples. Using vowel F1 and F2 measurements taken from informal interviews with 27 speakers from The Sunset district in San Francisco, a primarily white and Asian neighborhood, the vowel spaces of these speakers were examined. The aim of this project was to determine if racial/ethnic status as monoracial (Asian or White) or mixed-race had a significant effect on speakers' vowel quality and their level of participation in the CVS. Quantitative analysis found that speakers' vowel systems do exhibit the characteristics of CVS. For the back vowels /ɑ/, /ɔ/, /ʌ/, /ʊ/, /u/, and /o/ difference between speakers of mixed race and their white counterparts were found to be statistically significant.

Characteristics of Alveolo-palatal Affricates Produced by Mandarin-speaking Children with Repaired Cleft Palate.

Objectives: In this study, examined the acoustic properties of affricates /t/ and /th/ in Mandarin Chinese, and analyzed the differences of the acoustic characteristics of these affricates produced by children with repaired cleft palate and normally developing children. We also explored the relationship between the affricates and high-front vowel /i/. Methods: We analyzed 16 monosyllabic words with alveolo-palatal affricates as the initial consonants produced by children with repaired cleft palate (N=13, Mean=5.9 years) and normally developing children (N=6, Mean age=5.3 years). We used several acoustic parameters to investigate the characteristics of these affricates, such as the center of gravity, VOT and the formants of vowels. Results: Compared with normally developing children, children with cleft palate exhibited a lower center of gravity for the 2 affricates /t/ and /th/. Data from the control group showed that the affricate /th/ had a significantly greater center of gravity than that of /t/. The accuracy of /t , th/ produced by speakers of cleft palate was significantly correlated with that of /i/ (r=0.63). High-front vowel /i/ is a significant index in diagnosing speech intelligibility which is more valuable than /a/ and /u/. There was a significant difference in F2 of vowel /i/ between children with cleft palate without speech therapy (CS1) and after speech therapy (CS2). After speech intervention, the accuracy of affricates produced by children with cleft palate was improved, the acoustic properties "stop + noise segments" appeared. Conclusion: Children with cleft palate can be distinguished better from children with normal development by 2 significant acoustic characteristics: center of gravity and VOT. As alveolo-palatal affricates /t , th/ and high-front vowel /i/ have a similar place of articulation, front-tongue-blade, their production accuracy can be improved mutually. The analysis showed that the articulation of Chinese /i/ has a higher frontal lingual position and less variability, which is more conducive to articulation training and improves the effect of cleft palate training. These findings provide a potential relationship on affricates /t, th/ and vowel /i/. Children with cleft palate have difficulty pronouncing the /t, t h/ and /i/. It is better to start with a vowel /i/, resulting in improvement in overall speech intelligibility.

Lithuanian and Latvian laterals: Comparison of acoustic properties

The aim of the paper is to examine how acoustic contrast manifests itself between /l/ and /ʎ/ in Latvian, as well as /l/ and /lʲ/ in Lithuanian. For the study, speech recordings of 6 adult informants (3 Lithuanian and 3 Latvian male speakers) have been analysed. Initial and final laterals in closed symmetric [l]V[l] sequences and intervocalic syllable-initial laterals in V[l]V sequences have been examined. During the analysis, the focus is placed mainly on locus equations, as well as changes in formant structure (especially F1 and F2) triggered by position and vocalic context. Acoustic data demonstrates differences in coarticulation effects between Latvian palatal /ʎ/ and Lithuanian palatalized /lʲ/. The formant structure of /ʎ/ and /lʲ/, unlike the corresponding non-palatal laterals, is more stable and less dependent on the quality of adjacent vowels. Vowel context affects the degree of palatalization, e. g. palatalized [lʲ] next to [ɪ], [iː] and [eː] is pronounced “softer” than next to [ɔ̟], [o̟ː], [ʊ̟], and [u̟ː]. Latvian /ʎ/ is characterized by a more stable vowel F2 locus, which indicates higher degree of coarticulatory resistance to vowel effects; the quality of /lʲ/, on the contrary, depends more on vowel context. The same is true (although to lesser degree) for the Lithuanian /l/. The assumption about the similarity of Latvian non-palatal /l/ and Lithuanian palatalized /lʲ/ is only partly supported by the recent data. In terms of the degree of coarticulation (indicated by slope values of locus equations), Latvian /l/ is closer to Lithuanian /lʲ/, while its formant structure, especially low F2, brings it closer to Lithuanian /l/.

Acoustic Measurements of Speech and Voice in Men with Angle Class II, Division 1, Malocclusion.

Introduction The acoustic analysis of speech (measurements of the fundamental frequency and formant frequencies) of different vowels produced by speakers with the Angle class II, division 1, malocclusion can provide information about the relationship between articulatory and phonatory mechanisms in this type of maxillomandibular disproportion. Objectives To investigate acoustic measurements related to the fundamental frequency (F0) and formant frequencies (F1 and F2) of the oral vowels of Brazilian Portuguese (BP) produced by male speakers with Angle class II, division 1, malocclusion (study group) and compare with men with Angle class I malocclusion (control group). Methods In total, 60 men (20 with class II, 40 with class I) aged between 18 and 40 years were included in the study. Measurements of F0, F1 and F2 of the seven oral vowels of BP were estimated from the audio samples containing repetitions of carrier sentences. The statistical analysis was performed using the Student t -test and the effect size was calculated. Results Significant differences ( p -values) were detected for F0 values in five vowels ([e], [i], [ᴐ], [o] and [u]), and for F1 in vowels [a] and [ᴐ], with high levels for class II, division 1. Conclusion Statistical differences were found in the F0 measurements with higher values in five of the seven vowels analysed in subjects with Angle class II, division 1. The formant frequencies showed differences only in F1 in two vowels with higher values in the study group. The data suggest that data on voice and speech production must be included in the protocol's assessment of patients with malocclusion.

Egyptian vowel second formant in isolation and in transition following high-frequency fricatives by NLFC hearing aid in children: how does the pattern compare to typically hearing peers?

BackgroundHigh-frequency consonants form an area of difficulty among children with hearing impairment. Many technological setups have emerged in order to improve their audibility, among them nonlinear frequency compression (NLFC). Therefore, the following study was carried out in order to evaluate change in production of high-frequency fricatives by hearing-impaired children utilizing NLFC hearing aids. This was through spectrographic analysis of F2 onset of transition elicited by fricatives in a prevocalic context, and results were compared to typically developing (TD) children. A change in mid-frequency sounds due to high-frequency compression was also tested through production of sustained vowels in isolation.ResultsA preliminary prospective case-control study involved 9 patients with NLFC hearing aids, evaluated at 1- and at 6-month post-fitting, without receiving speech therapy. Spectrographic analysis of F2 formant onset in [a] and [i] vowels when combined with [s] and [f] fricatives in a CV (consonant-vowel) pattern, presented auditorily and audio-visually, was observed and analyzed. One patient was excluded due to noncompliance in attendance. In the 8 patients who completed the study, very high-frequency level of F2 onset in CV was notable in second versus first evaluation in NLFC group, to the extent of surpassing the typical value in TD control group with [i] vowel. Contrastingly, F2 of sustained vowels in isolation took a trend of a lower value after 6 months of NLFC hearing aid use, as compared to the first evaluation. Consequently, the gap between sustained vowel F2 level in TD and NLFC groups widened.ConclusionMean high-frequency range of F2 onset of transition in CV patterns of voiceless fricatives [s] and [f] with [i] and [a] vowels 6 months after NLFC fitting reflects an enhancement in the frequency range production of these sounds. A shift toward a lower F2 frequency range in sustained mid-frequency vowels, on the other hand, remains to be carefully investigated as a sequel of nonlinear frequency compression in the Egyptian hearing-impaired children.

A dual mechanism for intrinsic f0

Vowel-intrinsic fundamental frequency (IF0), the phenomenon that high vowels tend to have a higher fundamental frequency (f0) than low vowels, has been studied for over a century, but its causal mechanism is still controversial. The most commonly accepted “tongue-pull” hypothesis successfully explains the IF0 difference between high and low vowels but fails to account for gradient IF0 differences among low vowels. Moreover, previous studies that investigated the articulatory correlates of IF0 showed inconsistent results and did not appropriately distinguish between the tongue and the jaw. The current study used articulatory and acoustic data from two large corpora of American English (44 speakers in total) to examine the separate contributions of tongue and jaw height on IF0. Using data subsetting and stepwise linear regression, the results showed that both the jaw and tongue heights were positively correlated with vowel f0, but the contribution of the jaw to IF0 was greater than that of the tongue. These results support a dual mechanism hypothesis in which the tongue-pull mechanism contributes to raising f0 in non-low vowels while a secondary “jaw-push” mechanism plays a more important role in lowering f0 for non-high vowels.

How does focus-induced prominence modulate phonetic realizations for Korean word-medial stops?

Previous research has indicated that the patterns of phonetic modulations induced by prominence are not consistent across languages but are conditioned by sound systems specific to a given language. Most studies examining the prominence effects in Korean have been restricted to segments in word-initial and phrase-initial positions. The present study, thus, set out to explore the prominence effects for Korean stop consonants in word-medial intervocalic positions. A total of 16 speakers of Seoul Korean (8 males, 8 females) produced word-medial intervocalic lenis and aspirated stops with and without prominence. The prominence was induced by contrast focus on the phonation-type contrast, that is, lenis vs. aspirated stops. Our results showed that F0 of vowels following both lenis and aspirated stops became higher when the target stops received focus than when they did not, whereas voice onset time (VOT) and voicing during stop closure for both lenis and aspirated stops did not differ between the focus and no-focus conditions. The findings add to our understanding of diverse patterns of prominence-induced strengthening on the acoustic realizations of segments.

An acoustic phonetic description of Nungon vowels.

This study is a comprehensive acoustic description and analysis of the six vowels /i e a u o ɔ/ in the Towet dialect of the Papuan language Nungon ⟨yuw⟩ of northeastern Papua New Guinea. Vowel tokens were extracted from a corpus of audio speech recordings created for general language documentation and grammatical description. To assess the phonetic correlates of a claimed phonological vowel length distinction, vowel duration was measured. Multi-point acoustic analyses enabled investigation of mean vowel F1, F2, and F3; vowel trajectories, and coarticulation effects. The three Nungon back vowels were of particular interest, as they contribute to an asymmetrical, back vowel-heavy array, and /o/ had previously been described as having an especially low F2. The authors found that duration of phonologically long and short vowels differed significantly. Mean vowel formant measurements confirmed that the six phonological vowels form six distinct acoustic groupings; trajectories show slightly more formant movement in some vowels than was previously known. Adjacent nasal consonants exerted significant effects on vowel formant measurements. The authors show that an uncontrolled, general documentation corpus for an under-described language can be mined for acoustic analysis, but coarticulation effects should be taken into account.

Quantitative analysis of vowel production in cerebral palsy children with dysarthria

ObjectiveThe present study aimed to identify certain acoustic parameters for speech evaluation in cerebral palsy children with dysarthria. MethodsThe subject included 30 native Mandarin-Speaking children with cerebral palsy, who were 5–15 years old, and 13 healthy children in a similar age range. Each subject was recorded while producing a list of 12 Mandarin words, which included three syllables (‘ba’, ‘bi’ and ‘du’), in all four Mandarin tones. The formants (F1 and F2) of monophthong vowels /a, i, u/ were extracted from each vowel token. Based on F1 and F2, the vowel acoustic indexes VSA, VAI and FCR were calculated and analyzed. ResultsCompared with the control group, the cerebral palsy group had significantly low F1 and F2 in vowel /a/ (P < 0.05), and F2 in vowel /i/ (P < 0.05), while F1 and F2 in vowel /u/ and F1 in vowel /i/ had no significant difference. Between the healthy group and cerebral palsy group, the differences in VSA, VAI and FCR were all statistically significant. ConclusionChildren with cerebral palsy have reduced vowel space and speech articulation. The significant difference in vowel acoustic indexes (VSA, VAI and FCR) among the two groups revealed that the three indexes were sensitive to the variation of the vowels production in children with cerebral palsy, and that these may be used as an evaluation method of speech intelligibility caused by impaired vowel pronunciation in children with cerebral palsy, and the effect of rehabilitation therapy.

The Role of Acoustic Distance and Sociolinguistic Knowledge in Dialect Identification.

Listeners are able to quite accurately distinguish between different dialects of their native language, but little is known about the process of dialect identification and the phonetic cues listeners use to identify someone’s regional origin. This study examines how different segments, acoustic between-dialect distance, and the listeners’ knowledge about a dialect contribute to this process. Native speakers of Grison and Zurich German were asked to categorise isolated words spoken by eight speakers of Grison and eight speakers of Zurich German. Stimuli contained either none, one, or two segmental cues to regional origin. The presence of one dialect-specific segment was enough to allow for an identification rate well above chance. Sensitivity measures and analysis of reaction time showed that the two dialect groups largely relied on the same segmental cues. Acoustic distance to the other dialect, quantified as Euclidean distance in the F1 × F2 vowel space, generally facilitated dialect identification, but interacted with native speakers’ knowledge about the dialects: in segments which listeners explicitly associated with one of the two dialects, acoustic distance facilitated dialect recognition to a larger extent than in segments in which listeners were not aware of dialectal variation. The results suggest that, depending on the listener’s prior knowledge about a dialect, acoustic variation is weighted differently. Further analysis showed that Zurich listeners were more sensitive to the dialect differences, responded faster, and presented a more marked own-dialect response bias than Grison listeners. These findings are in line with the status of Grison German as a marked dialect and Zurich German as a neutral dialect, and suggest that, depending on their own dialect’s status, listeners used different decision strategies.

Auditory prediction during speaking and listening

In the present EEG study, the role of auditory prediction in speech was explored through the comparison of auditory cortical responses during active speaking and passive listening to the same acoustic speech signals. Two manipulations of sensory prediction accuracy were used during the speaking task: (1) a real-time change in vowel F1 feedback (reducing prediction accuracy relative to unaltered feedback) and (2) presenting a stable auditory target rather than a visual cue to speak (enhancing auditory prediction accuracy during baseline productions, and potentially enhancing the perturbing effect of altered feedback). While subjects compensated for the F1 manipulation, no difference between the auditory-cue and visual-cue conditions were found. Under visually-cued conditions, reduced N1/P2 amplitude was observed during speaking vs. listening, reflecting a motor-to-sensory prediction. In addition, a significant correlation was observed between the magnitude of behavioral compensatory F1 response and the magnitude of this speaking induced suppression (SIS) for P2 during the altered auditory feedback phase, where a stronger compensatory decrease in F1 was associated with a stronger the SIS effect. Finally, under the auditory-cued condition, an auditory repetition-suppression effect was observed in N1/P2 amplitude during the listening task but not active speaking, suggesting that auditory predictive processes during speaking and passive listening are functionally distinct.

Regional Variation in Fundamental Frequency of American English Vowels

We examined whether the fundamental frequency (f0) of vowels is influenced by regional variation, aiming to (1) establish how the relationship between vowel height and f0 (“intrinsic f0”) is utilized in regional vowel systems and (2) determine whether regional varieties differ in their implementation of the effects of phonetic context on f0 variations. An extended set of acoustic measures explored f0 in vowels in isolated tokens (experiment 1) and in connected speech (experiment 2) from 36 women representing 3 different varieties of American English. Regional differences were found in f0 shape in isolated tokens, in the magnitude of intrinsic f0 difference between high and low vowels, in the nature of f0 contours in stressed vowels, and in the completion of f0 contours in the context of coda voicing. Regional varieties utilize f0 control in vowels in different ways, including regional f0 ranges and variation in f0 shape.

Tongue- and Jaw-Specific Contributions to Acoustic Vowel Contrast Changes in the Diphthong /ai/ in Response to Slow, Loud, and Clear Speech.

This study sought to determine decoupled tongue and jaw displacement changes and their specific contributions to acoustic vowel contrast changes during slow, loud, and clear speech. Twenty typical talkers repeated "see a kite again" 5 times in 4 speech conditions (typical, slow, loud, clear). Speech kinematics were recorded using 3-dimensional electromagnetic articulography. Tongue composite displacement, decoupled tongue displacement, and jaw displacement during /ai/, as well as the distance between /a/ and /i/ in the F1-F2 vowel space, were examined during the diphthong /ai/ in "kite." Displacements significantly increased during all 3 speech modifications. However, jaw displacements increased significantly more during clear speech than during loud and slow speech, whereas decoupled tongue displacements increased significantly more during slow speech than during clear and loud speech. In addition, decoupled tongue displacements increased significantly more during clear speech than during loud speech. Increases in acoustic vowel contrast tended to be larger during slow speech than during clear speech and were predominantly tongue-driven, whereas those during clear speech were fairly equally accounted for by changes in decoupled tongue and jaw displacements. Increases in acoustic vowel contrast during loud speech were smallest and were predominantly tongue-driven, particularly in men. Findings suggest that task-specific patterns of decoupled tongue and jaw displacement change and task-specific patterns of decoupled tongue and jaw contributions to vowel acoustic change across these speech modifications. Clinical implications are discussed.

An Experimental Study of Labial/Velar Alternation in Korean

The purpose of this paper is to find triggering factors of labial/velar alternation in Korean. Labial/ velar shift in Korean was found in the 15th century, and traces of labial/velar shift still remain in some dialects. Interestingly, it is often found in the speech of infants and adults even in standard Korean. This study focuses on finding phonetic and phonological cues of labial/velar alternation in Modern Korean, especially Seoul and Gyeonggi dialects by measuring F2 transitions and vowel distances after and before two phonemes /p/ and /k/ and through performance of two perceptual tasks. In the results, F2 transitions in back vowels are found to be similar regardless of syllable positions, but vowel distances were not relevant. As for the discrimination index d-prime, it decreased when back vowels preceded /p/ and /k/ in one-syllable words. It can be inferred that a phonetic and phonological similarity is asymmetrical from the results.