Gender Effects in the Phonetic Description of English Vowel Space. A Comparative Analysis of English Vowel Space Produced by Malaysian Chinese Femaleand Nigerian Male Hausa ESL Speakers

Cite this article as: Bello, H., & Abdullahi, J. (2025). Gender effects in the phonetic description of English vowel space: A comparative analysis of English vowel space produced by Malaysian Chinese female and Nigerian male Hausa ESL speakers. Sokoto Journal of Linguistics and Communication Studies (SOJOLICS), 1(3), 290–299. https://www.doi.org/10.36349/sojolics.2025.v01i01.034

GENDER EFFECTS IN THE PHONETIC DESCRIPTION OF ENGLISH VOWEL SPACE. A COMPARATIVE ANALYSIS OF ENGLISH VOWEL SPACE PRODUCED BY MALAYSIAN CHINESE FEMALEAND NIGERIAN MALE HAUSA ESL SPEAKERS

by

Bello, Hamza, Ph. D¹.  

Abdullahi, Jamilu, Ph. D²,

1,2 Sa’aduZungur University, Bauchi State.

¹hamzabello@sazu.edu.ng

²abdullahijamilu@sazu.edu.ng

Abstract

This research intends to provide a comprehensive account of phonetic description of English vowels focusing on gender- based differences in two under- researched nonnative English varieties, Nigerian English, specifically produced by 20male Hausa ESL speakers, and Malaysian English, specifically produced by 20female Chinese ESL speakers. The data was collected using the 10English pure vowels as stimuli. These vowels are (/iː/, /ɪ/, /e/, /æ/, /ʌ/, /ɜ:/, /ɔ/, /ɔ:/, /ʊ/, /uː/. the participants were recorded after they were instructed to produce the vowels while comfortability sitting in noise free environment with the aid of PRAAT software developed by Boersma, and Weenink (2013). The data was analyzed acoustically to reveal the formant values of the vowels under investigation. The results were used in pictorially drawing the vowel spaces for both the participants for comparison on the bases of gender. The finding reveals that the produced vowel space of the Hausa male speakers appears to be the smaller compared with the one produced by Chinese female participants,despite both being non-native and the L1 transfer (Hausa vs. Chinese) shapes vowel positioning, the gender effect was found to be evident in the production of vowel space. This phenomenon is pronounced and consistent with global phonetic patterns. These findings emphasize the importance of including gender as a variable in second language phonology research, pronunciation teaching, and speech technology development.

Keyword: Comparative, Gender Effects, Phonetic Description, English Vowel Space, Malaysian Chinese Female, Nigerian Male Hausa, ESL Speakers

1.      Introduction

Scholarly evidence from previously published studies has consistently indicated that biological differences between males and females contribute to observable variation in voice quantity and quality during speech production (Fu, Chinchilla, Nogaki, & Galvin, 2005). These variations are often perceptible through simple auditory exposure to male and female speech, reflecting systematic differences rather than random individual variation. Such differences have remained a central concern in phonetic and sociolinguistic research, particularly in the acoustic study of vowels, which are known to carry both linguistic and paralinguistic information.

The acoustic properties of speech sounds, especially vowels, have attracted sustained attention because of their sensitivity to speaker-specific factors. Among the most influential of these factors is gender, commonly operationalised through biological and physiological distinctions between male and female speakers (Biland & Irshad, 2025). Empirical research has repeatedly demonstrated that gender affects key acoustic parameters such as fundamental frequency (F0), vowel formant frequencies (F1, F2, F3), and overall vocal tract length (Pépiot& Arnold, 2021). These parameters play a critical role in shaping vowel quality and the size and configuration of vowel space.

Fundamental frequency, often referred to as F0, is widely recognised as one of the primary acoustic correlates of gender. Studies consistently show that female speakers tend to produce higher fundamental frequency values than male speakers (Zimman, 2017; Leung, Oates, Chan, & Papp, 2021; Signorello et al., 2020). In addition to F0 differences, vowel formant frequencies have also been shown to vary systematically by gender, with female speakers typically exhibiting higher formant values than their male counterparts (Gelfer & Bennett, 2013; Gallena, Stickels, & Stickels, 2018; Albuquerque et al., 2023). These acoustic patterns are largely attributed to anatomical differences, particularly the generally longer vocal tracts and larger laryngeal structures found in adult males, which result in lower resonance frequencies compared to females (Strycharczuk& Kirkham, 2025). Examining how these gender-based physiological differences manifest in vowel production is therefore essential for advancing theoretical models of speech production and for practical applications in areas such as speech technology, forensic phonetics, and second language pedagogy.

This study investigates the acoustic characteristics of ten English vowels as produced by Nigerian Hausa male speakers and Malaysian Chinese female speakers, with particular emphasis on formant patterns and vowel space dispersion. While earlier studies have established broad trends in gender-related acoustic variation, much of the existing literature has focused on native speakers from Western English-speaking communities (Johnson, Ladefoged, & Lindau, 1993; Bohn & Flege, 1992; Yang & Whalen, 2015). Consequently, less attention has been given to how these patterns operate among speakers of English as a second or foreign language from diverse linguistic backgrounds. The present study seeks to address this gap by analysing data from a balanced sample of forty undergraduate participants, comprising twenty Nigerian male Hausa ESL speakers and twenty Malaysian Chinese female ESL speakers. This cross-national design allows for an examination of whether established gender-based acoustic differences in vowel production persist across speakers with distinct first-language backgrounds, thereby offering deeper insight into the interaction between biological factors, linguistic experience, and second-language speech production.

Acoustic analysis provides a reliable and objective means of examining the relationship between speech production and perception. It enables precise measurement of speech signals and facilitates systematic comparison of vowel spaces across languages and speaker groups (Chen, 2000; Narang & Misra, 2010). The growth of acoustic phonetic research has been greatly enhanced by advances in digital technology, particularly the availability of computer-based tools and speech analysis software, which allow for accurate extraction and visualisation of acoustic parameters. As a result, acoustic analysis has become central to the empirical study of both native and non-native speech.

A substantial body of phonetic research has employed acoustic analysis to investigate English vowel production in both native and second-language contexts (Bradlow, 1995; Javed, 2013; Ali et al., 2023). Vowels are especially prominent in such studies because they form the acoustic nucleus of syllables and are highly salient in speech perception (Duris, 2021). Their production involves minimal obstruction in the vocal tract, as air flows freely from the lungs through an open articulatory configuration, making vowels particularly suitable for acoustic rather than articulatory description (Khalil, 2014).

Speech production relies on respiratory energy, with airflow from the lungs serving as the primary power source for sound generation (Kassaian, 2011). During vowel articulation, the vocal tract remains relatively open, with no complete closure or significant constriction, allowing continuous airflow and voicing. For this reason, vowels are best characterised by their acoustic structure, especially formant frequencies, rather than by discrete articulatory gestures (Yule, 2022).

Vowel space representation provides a graphical method for illustrating the acoustic distribution of vowels based on formant values. Typically, vowel space is plotted using the first two formants, with F1 on the vertical axis and F2 or the F2–F1 distance on the horizontal axis (Nigora, 2025). This two-dimensional representation corresponds closely to tongue height and frontness in articulatory space, offering an interpretable link between acoustic measurements and speech production mechanisms (Azeez, 2025; Yaqub, 2025). Through vowel space analysis, differences in vowel realisation across gender and speaker groups can be systematically examined, making it a suitable analytical framework for the objectives of the present study.

Figure 1. Vowel Acoustic space 

Configuration of the Vocal Tract in Acoustic Analysis

Variations in vowel quality may arise from differences in formant frequencies, which are shaped by the speaker’s vocal tract configurations during speech production. Among these are the first two formants, that is F1 and F2, as explained above are the lowest and most critical in distinguishing one vowel from another, playing a key role in defining both vowel quality and quantity (Slis, & Cohen, 1967; Peterson & Barney, 1952). It is widely accepted that F1 and F2 formant frequencies are closely linked to tongue position, which in turn alters the shape of the vocal tract (Raphael, Borden, & Harris, 2007).

One of the primary reasons for gender-based differences in vowel production lies in the anatomical variation in vocal tract length (VTL) between males and females. On average, adult males possess longer vocal tractstypically ranging from 16 to 18 cmcompared to females, whose vocal tracts average between 14 and 15 cm (Luo, & Meng, 2025). This difference directly influences formant frequencies, longer vocal tracts produce lower formant values (particularly F1 and F2), resulting in perceptually "deeper" or more resonant vowel sounds in male speech. Recent acoustic analyses by Li, and Al-Tamimi (2024) confirm that these VTL-driven shifts in formant spacing consistently differentiate male and female vowel spaces, even when controlling for linguistic and regional variables. Consequently, the physical structure of the vocal tract serves as a foundational factor in gendered vowel production.

While biological factors are central, recent research also highlights how gendered articulatory strategies interact with vocal tract configuration to shape vowel production. Studies show that women often employ more extreme tongue positions and greater jaw opening during vowel articulation, amplifying formant dispersion and enhancing vowel distinctiveness (Lu, Zhao, Wu, Kong, Gao, & Zhang, 2023; Heyne, Derrick, & Al-Tamimi, 2019; Chen, Whalen, & Mok, 2024). This may partially compensate for their shorter vocal tracts by maximizing acoustic contrast. Conversely, men’s articulatory patterns tend to be more centralized, aligning with their inherently lower formant frequencies. Particularly, cross-linguistic investigation by DiCanio, Nam, Amith, García, and Whalen (2015) revealed that these gendered articulatory tendencies persist across diverse languages and are reinforced by sociophonetic norms, suggesting that both physiology and social practice jointly influence vowel realization. Thus, the interplay between anatomical configuration and learned articulatory behavior accounts for the differences in male and female vowel production. The figure 2. below presents a sample of human vocal tract

Figure 2. The Human Vocal Tract

The current research is prompted by the luck of armfulstudies that engaged Hausa and Malaysian ESL students based on gender differences. It is believed that the outcome of the research will contribute to the on-going discussion on gender-based research in phonology.  

Research Questions

This research seeks to address specific gaps in understanding how biological differences influences the production of English vowel among non-native speakers from Hausa and Chinese linguistic backgrounds. The research is guided by the following research questions to investigate and clarify the extent and nature of male–female differences in the acoustic realization of 10 English vowels. 

1.      What are the acoustic properties of English vowels produced by Nigerians Hausa Male ESL students?

2.      What are the acoustic properties of English vowels produced by Malaysian ChineseFemaleESL students?

3.      How does Gender effects the phonetic description of English vowel space produced by Nigerians Hausa Male and Malaysian Chinese Female ESL students?

 

2.      Methodology

The study adopted an experimental acoustic phonetic approach to examine gender effects in English vowel production among Nigerian Hausa and Malaysian Chinese ESL speakers. Speech data were collected through controlled audio recordings using PRAAT software, which functioned as both the recording and analysis tool due to its reliability and wide acceptance in acoustic phonetic research for measuring fundamental frequency and vowel formant frequencies. Participants were recorded individually in quiet rooms in Nigeria and Malaysia to minimise background noise and ensure high-quality recordings. Each participant produced ten English words containing the target vowels within a carrier-phrase format to ensure consistency across tokens. The elicitation prompts included Please say “heed” again, Please say “hid” again, Please say “hayed” again, Please say “had” again, Please say “hod” again, Please say “hud” again, Please say “herd” again, Please say “hawed” again, Please say “hood” again, and Please say “who’d” again. These stimuli were selected to represent a wide range of English monophthongal vowel qualities, and all tokens were produced at a normal speaking rate to approximate natural speech while maintaining experimental control.

The participants consisted of forty undergraduate students selected through purposive sampling to ensure balanced representation across gender and linguistic background. The sample comprised twenty male Nigerian Hausa speakers and twenty female Malaysian Chinese speakers, all within the age range of 20 to 25 years, thereby ensuring age homogeneity and reducing age-related variation in vowel production. All participants shared a comparable educational background and similar exposure to English as a second or foreign language. Following data collection, the recorded tokens were segmented and analysed acoustically using PRAAT, with measurements focusing on fundamental frequency (F0) and the first two formant frequencies (F1 and F2). These measurements were used to construct vowel space representations and to examine gender-based differences in vowel production. The combination of a controlled recording environment, standardised stimuli, and a balanced participant sample enhanced the reliability and comparability of the acoustic data across gender and linguistic groups.

3.      Data Presentation and Analysis

To determine the acoustic properties of English vowels produced by Nigerian HausaMale ESL speakers, the participants were subjected to voice recordingduring the production session. PRAAT acoustic software was used in measuring the acoustic properties ofthe vowels produced. The averaged formant values for both the F1 and F2 in Hz at mid position was used for. The results are presented, following the already formulated research questions one after the other.

RQ1. What are the acoustic properties of English vowels produced by Nigerians Hausa Male ESL students?

Table 2: Average F1 and F2 vowel formants by Nigerians (Hausa) Male ESL speakers

	Gender	/iː/	/ɪ/	/e/	/æ/	/ʌ/	/ɜ:/	/ɔ/	/ɔ:/	/ʊ/	/uː/
F1(Hz)	M	295	390	550	700	710	705	708	540	395	310
F2(Hz)	M	2170	2130	1875	1510	1505	1508	1050	1000	1000	1010

Bello, Yap, Chan, and Nimehchisalem (2020).

The table presents the results of vowel production by 20 Nigerian male ESL speakers in which the first (F1) and second (F2) formant frequencies of ten English monophthongs were analyzed. The result summarized and reveal systematic patterns in the articulation of the participants. For F1 (in Hz), the highest values were observed for /æ/ (700 Hz), /ʌ/ (710 Hz), and /ɜː/ (705 Hz), indicating relatively open vowel articulations, while the lowest F1 values occurred for the high vowels /iː/ (295 Hz) and /uː/ (310 Hz), consistent with their close tongue positions. F2 values (in Hz) showed a clear front-to-back distinction: front vowels such as /iː/ (2170 Hz), /ɪ/ (2130 Hz), /e/ (1875 Hz), and /æ/ (1510 Hz) exhibited higher F2 frequencies, whereas back vowels including /ʊ/ (1000 Hz), /uː/ (1010 Hz), /ɔ/ (1050 Hz), and /ɔː/ (1000 Hz)displayed markedly lower F2 values. Markedly, the central vowels /ʌ/ and /ɜː/ clustered around 1500-1510 Hz in F2, aligning them acoustically with mid-central articulations. These findings suggest that while Nigerian ESL speakers generally maintain the expected F1-F2 vowel space organization, certain mergers or compressions particularly among back vowels may reflect the influence of their native phonological systems on English vowel production.

Figure 3: Visual display of English vowels by Nigerians (Hausa) Male ESL speakers

The Figures3 above visually displays the acoustic space of English vowels produced by male Hausa ESL speakers, which were drawn in excel sheet using the F1 X F2 value measured from the midpoint of the vowels under investigation as indicated earlier for /iː/, /ɪ/, /e/, /æ, /ʌ, /, /ɜ:/, /ɔ/, /ɔː/, /ʊ, /uː/. The chart has demonstrated that most of the sounds produced by Hausa ESL speaker’s male were produced sufficiently in the phonetic space. However, only in three vowels i.e. {/æ/, /ʌ/, /ɜ:/} were found with overlapping space.

RQ2. What are the acoustic properties of English vowels produced by Malaysian ChineseFemale ESL students?

To determine the acoustic properties of English vowels produced by Malaysian ChinseFemale ESL students, like the first one the participants were subjected to voice recording during the production session.  PRAAT acoustic software was used in measuring the acoustic properties the vowels produced. The averaged formant values for both the F1 and F2 in Hz at mid position was used for. The results are presented below.

Table 3: Average F1 and F2 vowel formants by Malaysian Chinese Female ESL speakers

	Gender	/iː/	/ɪ/	/e/	/æ/	/ʌ/	/ɜ:/	/ɔ/	/ɔ:/	/ʊ/	/uː/
F1(Hz)	F	345	485	572	855	815	799	777	609	432	402
F2(Hz)	F	2810	2530	2508	2185	1198	1294	990	1055	868	868

20 Malaysian Chinese female ESL speakers produced the acoustic characteristics of ten English monophthongs through measurements of the first (F1) and second (F2) formant frequencies. As shown in the table, F1 values (in Hz) followed the expected inverse relationship with vowel height: low vowels such as /æ/ (855 Hz) and /ʌ/ (815 Hz) exhibited the highest F1 frequencies, reflecting open jaw positions, while high vowels /iː/ (345 Hz) and /uː/ (402 Hz) showed the lowest F1 values, consistent with close articulations. F2 values (in Hz) revealed a clear front-back distinction, with front vowels displaying substantially higher F2 frequencies/iː/ (2810 Hz), /ɪ/ (2530 Hz), /e/ (2508 Hz), and /æ/ (2185 Hz)whereas back vowels clustered at the lower end of the F2 range: /ʊ/ and /uː/ both at 868 Hz, /ɔ/ at 990 Hz, and /ɔː/ at 1055 Hz. Notably, the central vowels /ʌ/ (F2: 1198 Hz) and /ɜː/ (F2: 1294 Hz) occupied an intermediate F2 space, though closer to back vowels acoustically. The relatively high F2 for /æ/ and the compressed F2 range among back vowelsparticularly the identical F2 values for /ʊ/ and /uː/suggest potential vowel mergers or L1-influenced articulatory patterns, possibly reflecting the phonological influence of Malaysian Chinese languages on English vowel production.

Figure 4: Visual display of English vowels by Malaysian (Chinese) female ESL speakers

Figure 4. above displays the formant frequencies (F1 and F2) of ten English monophthongs produced by Chinese female ESL student. In this conventional vowel chart layout. F2 (frequency in Hz) is plotted on the x-axis, decreasing from left to right, so front vowels (higher F2) appear on the left, and back vowels (lower F2) on the right. F1 (frequency in Hz) is plotted on the y-axis, decreasing from bottom to top, so close (high) vowels (lower F1) appear at the top, and open (low) vowels (higher F1) at the bottom.

RQ3. How does Gender effects the phonetic description of English vowel space produced by Nigerians Hausa Male and Malaysian Chinese Female ESL students?

Figure 5.  presents a comparative acoustic analysis of English monophthong production by a Hausa male ESL speaker and a Chinese female ESL speaker, based on measured first (F1) and second (F2) formant frequencies. The data reveal significant differences in vowel space size and positioning, consistent with documented gender-based variation in speech production. Based on the comparison, the Chinese female speaker exhibits a larger overall vowel space compared to the Hausa male speaker. Front vowels: The female’s /iː/ (F2 = 2810 Hz) and /æ/ (F2 = 2185 Hz) are markedly more fronted than the male’s counterparts (F2 = 2170 Hz and 1510 Hz, respectively). Vertical dispersion: The female shows greater F1 range (345-855 Hz) vs. male (295-710 Hz), indicating more extreme high-to-low articulation. This aligns with well-established phonetic research showing that female speakers typically produce larger vowel spaces than males, partly due to anatomical differences (shorter vocal tracts) and partly due to sociolinguistic factors (e.g., clearer speech, identity performance).

4.      Discussion

This study undertakes a comparative acoustic analysis to investigate the variability in acoustic vowel space of the English vowel production by the participants (Hausa and Chinese ESL students). Previous research in acoustic phonetics has often employed similar comparative approaches, examining two or more languages or speaker groups (Narang & Misra, 2010). For instance, Bradlow (1995) compared the acoustic vowel spaces of English and Spanish to examine how vowels are realized in each language. The findings revealed that the English vowel /ɪ/ has lower F1 values than its Spanish counterpart, and English /e/ similarly exhibits lower F1 than Spanish /e/. In contrast, the back vowel /o/ was produced with a higher F1 (i.e., a more open articulation) in English than in Spanish. No significant differences were observed for the vowel /u/ between the two languages. Bradlow concluded that even though languages may share phonemic vowel categories, but they may occupy distinct regions in the acoustic space, reflecting language-specific articulatory patterns. This phenomenon was also found in the current research where the vowels produced by the two groups under comparison differed considerably in the acoustic space. 

Similarly, Lee and Narang (2010) conducted a comparative analysis of the vowel spaces of Korean and Hindi, highlighting differences between the two systems and discussing their implications for language teaching and forensic speaker identification. Although Korean and Hindi share several vowel phonemes, the study found that these vowels are organized differently within their respective acoustic spaces. Specifically, no significant differences were observed in the F1 and F2 values for the vowel /i/ across the two languages. However, the Korean /e/ was found to be articulated higher and more fronted than its Hindi counterpart, indicating that it is more centralized and open in Korean. Additionally, the vowels /a/, /o/, and /u/ were relatively more centralized in Korean compared to their Hindi equivalents, further underscoring the language-specific organization of shared vowel categories.

Similar findings were reported in a study by Lucic (2015), which compared the acoustic characteristics of English vowels produced by Montenegrin L2 speakers with those of General American English (GAE) native speakers. The results indicated that Montenegrin learners experienced difficulties in accurately producing certain English vowels, often articulating them in a lower region of the vowel space than their GAE counterparts. Notably, the production of /i/ and /ɪ/ by Montenegrin speakers encroached upon the acoustic space typically occupied by the GAE /e/ vowel. The acoustic distance between Montenegrin /i/ and GAE /e/ was found to be just 1 Hz, while the phonetic distance between GAE /e/ and Montenegrin /ɪ/ was only 9 Hz. According to Ferrand, Méot, Spinelli, New, Pallier, Bonin, & Grainger (2018), human listeners are generally unable to perceive audible distinctions between vowels separated by less than 60 Hz, suggesting that the minimal acoustic separation in this case likely leads to perceptual confusion and reduced contrast among these vowel categories, supporting the hypothesis that such close phonetic proximity poses a significant challenge for both production and perception.

Pillai and Salaemae (2012) conducted an instrumental analysis of English monophthongs produced by Thai EFL learners, investigating how these learners articulate English vowel sounds. Their findings revealed a clear influence of the Thai language on the learners’ ability to maintain distinct contrasts between certain English vowels, particularly /e/ and /æ/. Additionally, the study identified cross-linguistic interference in vowel quality, with Thai phonological patterns affecting the production of several English vowels, including /e/, /i/, /ɔː/, /æ/, and /uː/. This suggests that the native Thai sound system plays a significant role in shaping the phonetic realization of English vowels among Thai EFL speakers.This finding is also observed in the present study, /i:/ and  /ɪ/ were categorized as the highest position by the Hausa in the vowel space than /i:/ and  /ɪ/ of Chinese Malaysian Chinese. There seems to be no differences in the categorization of /e/ vowel  across the two groups. However, the low vowel /ᴂ/ was categorized differently by the groups.

The findings of this study reveal a significantly larger acoustic vowel space among Malaysian Chinese female speakers compared to their Nigerian Hausa male counterparts. This observation aligns with a robust body of recent literature underscoring gender as a critical sociophonetic variable in vowel production. For instance, Funk and Simpson (2023) have demonstrated that female speakers, across diverse L1 backgrounds, consistently exhibit greater dispersion in F1-F2 space, attributed to both physiological factors (e.g., shorter vocal tracts yielding higher formant frequencies) and sociolinguistic motivations, such as heightened articulatory precision or identity performance. In the present data, Malaysian Chinese females produced front vowels like /iː/ (F2 = 2810 Hz) and /æ/ (F2 = 2185 Hz) with markedly higher F2 values and greater vertical spread in F1 than Nigerian Hausa males (/iː/: F2 = 2170 Hz; /æ/: F2 = 1510 Hz), resulting in a more expansive and differentiated vowel triangle. This acoustic expansion suggests that gender, intersecting with L1 phonological structure, plays a pivotal role in shaping ESL vowel articulation.

While gender effects are evident, they do not operate in isolation, rather, they interact dynamically with first-language phonological constraints. The Nigerian Hausa male participants, whose L1 (Hausa) has a relatively compact five-vowel system (/i, e, a, o, u/), exhibited a compressed English vowel space, particularly in the front vowel region, where distinctions between /ɪ/, /e/, and /æ/ were acoustically neutralized. In contrast, although Mandarin and other Chinese dialects (spoken by the Malaysian Chinese participants) also feature fewer vowel phonemes than English, the female speakers leveraged gender-linked articulatory strategies to maximize contrast in their L2 production. As noted by Munro (2023), female L2 learners often employ hyperarticulation as a compensatory mechanism to overcome L1 transfer limitations, thereby enhancing intelligibility. This may explain why Malaysian Chinese females not only maintained clearer front-back distinctions (e.g., /uː/ F2 = 868 Hz vs. /iː/ F2 = 2810 Hz) but also achieved greater height differentiation (e.g., /æ/ F1 = 855 Hz vs. /iː/ F1 = 345 Hz). Thus, the interplay between gender and L1 phonology emerges as a key determinant of vowel space configuration in ESL contexts.

These findings contribute meaningfully to contemporary gender-based phonetic research by challenging purely biological explanations of vowel space differences and foregrounding the role of sociocultural and cognitive factors. Even though, work by Weirich,& Simpson (2013), emphasize that “larger” vowel spaces in female speakers are not merely anatomical but often reflect conscious or subconscious efforts to conform to norms of clarity, prestige, or intelligibilityespecially in multilingual settings like Malaysia, where English is a high-stakes lingua franca. Conversely, Nigerian Hausa male speakers, operating within a different sociolinguistic ecology where English may carry distinct indexical meanings, may prioritize fluency or L1 phonological economy over maximal vowel dispersion. From a pedagogical standpoint, this study underscores the need for gender-sensitive approaches in ESL pronunciation instruction. As argued by Sonsaat-Hegelheimer, and Levis, (2025), teaching materials and assessment criteria should account for how gender mediates L2 phonetic acquisition, particularly in vowel systems where acoustic contrast is crucial for intelligibility. Ultimately, this research affirms that gender is not a peripheral variable but a central axis around which phonetic variationand its pedagogical managementrevolve.

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