The mid front unrounded vowel is a type of vowel sound used in various spoken languages, characterized by a tongue position at mid-height—roughly halfway between the highest (close) and lowest (open) positions—in the front of the vocal tract, with the lips unrounded and spread.[1] It is typically represented in the International Phonetic Alphabet (IPA) by the symbol ⟨e⟩, which denotes the close-mid variant, though a true mid realization (exactly equidistant from close and open) lacks a dedicated basic symbol and is transcribed with diacritics such as lowered ⟨e̞⟩ or raised ⟨ɛ̝⟩ for precision.[2][3]This vowel is generally produced as a tense sound, involving greater muscular tension in the vocal tract compared to its lax counterpart, the open-mid front unrounded vowel [ɛ].[3][4] In terms of articulation, the body of the tongue arches upward and forward toward the hard palate, while the jaw remains moderately open, and the lips maintain a neutral or slightly spread configuration without protrusion.[1][5] Acoustically, it features a relatively low first formant (F1) frequency around 400–700 Hz, indicating mid height, and a high second formant (F2) above 2000 Hz, reflecting its front position.[6]The mid front unrounded vowel appears as a phoneme in numerous languages worldwide, contributing to contrasts in meaning; for instance, in Spanish, it distinguishes words like mesa [ˈme.sa] 'table' from those with other vowels.[7][8] Similarly, in Japanese, the vowel in え (e) is realized as , serving as one of the five basic vowel phonemes.[9] In English, a similar sound occurs as the initial element in the diphthong /eɪ/ of words like bait or made in certain dialects, though it is often diphthongized.[4][10] Its presence varies across dialects and languages, sometimes merging with nearby vowels like [ɛ] or [eɪ] due to phonetic processes such as raising or lowering influenced by surrounding consonants.[11]
Phonetic Description
Height and Position
The mid front unrounded vowel is classified as a close-mid vowel, with the tongue body raised to a height halfway between that of close (high) vowels and the central mid position, in the front of the oral cavity.[12][13] This positioning places the highest point of the tongue roughly midway between the close and open extremes, creating a balanced vertical dimension in the vowel space.[14]In terms of horizontal positioning, the vowel features front articulation, where the body of the tongue is advanced toward the front of the mouth, with its highest point located beneath the hard palate, distinguishing it from central or back vowels that involve more retracted tongue placement.[12][15] This forward tongue advancement contributes to the vowel's perceptual front quality, as exemplified by the close-mid variant represented as ⟨e⟩ in the International Phonetic Alphabet.Within the IPA vowel trapezium chart, the mid front unrounded vowel occupies the upper-middle region on the left side, positioned below high front vowels like and above low front vowels like , while to the right of central vowels and left of back vowels, visually mapping the tongue's sagittal elevation and anteroposterior placement in the vocal tract.[13] The chart's trapezoidal shape approximates the natural constraints of the oral cavity, with the mid front area reflecting a tongue configuration that is elevated yet forward without palatal contact.[14]The classification of mid-height vowels traces its roots to 19th-century phonetics, particularly the work of Henry Sweet, whose vowel charts emphasized tongue height gradations (high, mid, low) and positional advancements, influencing the standardization of the IPA vowel system in the late 19th and early 20th centuries.[14] Sweet's articulatory descriptions, building on earlier European phonetic traditions, helped establish mid as a distinct category intermediate between extremes, paving the way for the modern IPA trapezium.
Rounding and Other Features
The mid front unrounded vowel features a lip configuration that is spread or neutral, with the corners of the mouth drawn slightly apart and no protrusion or pursing, distinguishing it sharply from rounded front vowels such as the mid front rounded [ø]. This unrounded posture aligns with the general pattern for front vowels, where lip spreading enhances the acoustic frontness by increasing the oral cavity's resonance in higher frequencies. In the International Phonetic Alphabet (IPA) chart, is positioned to the left of the front vowel line to indicate its unrounded nature, as established in the cardinal vowel system developed by Daniel Jones.[2][16]As a secondary articulatory trait, the vowel is typically oral, with the velum raised to block nasal airflow, and voiced due to vocal cord vibration, though devoicing can occur in specific prosodic contexts across languages. Nasalization is not intrinsic but arises through coarticulation with adjacent nasals or as a phonemic contrast in select languages; for instance, Sindhi maintains a distinction between oral and nasal [ẽ], the latter marked by the tilde diacritic to denote lowered velum and nasal resonance.[2][16]Nasalization can occur allophonically through coarticulation with adjacent nasal consonants in many languages, such as English.[17]The vowel's quality often involves a degree of muscular tension in the tongue and vocal tract, rendering it tense relative to the lax open-mid [ɛ] in phonological systems that distinguish them, such as in Canadian English where (as in the first element of the diphthong /eɪ/) exhibits greater articulatory effort and longer duration. This tension influences phonological behavior, including resistance to reduction in stressed syllables and contributions to vowel harmony patterns in languages like Hungarian, where long [eː] is more peripheral and tense than short . However, realizations can vary, with shorter or unstressed tokens approaching lax qualities in duration and spectral centering.[18][2]Prior to the IPA's formalization in the late 19th century, this vowel faced misclassifications in non-IPA systems, particularly in pre-IPA European linguistics where it was broadly termed "short e" without precise height differentiation, often overlapping with more open variants in descriptions of Germanic and Romance languages and leading to inconsistencies in transcription. The IPA's evolution from earlier systems like the 1847 Visible Speech alphabet refined these distinctions, establishing as a standardized close-mid unrounded reference.[2]
IPA Representation
Primary Symbols
The primary symbol for the mid front unrounded vowel in the International Phonetic Alphabet (IPA) is ⟨e⟩, which represents a close-mid front unrounded vowel but is often used in a non-specific sense for mid height without precise distinction between close-mid and open-mid realizations.[19][2] This notation is detailed in the Handbook of the International Phonetic Association (1999), with the IPA chart revised to 2020 maintaining ⟨e⟩ as the standard for this vowel quality.[20]The symbol ⟨e⟩, corresponding to the Latin small letter e (Unicode U+0065), is encoded in the Basic Latin block and can be input via standard keyboards using the 'e' key.In broad phonetic transcription, ⟨e⟩ denotes the mid front unrounded vowel without specifying exact height precision, making it suitable for general linguistic descriptions where fine articulatory details are not required.[2]Historically, ⟨e⟩ was introduced as part of the IPA's founding alphabet in 1888 by the International Phonetic Association and refined in early revisions around 1900.[21][22]
Diacritic Variants
The mid front unrounded vowel, primarily represented by the symbol ⟨e⟩, can be modified using diacritics to specify variations in height for more precise phonetic transcription. A lowered variant is denoted as ⟨e̞⟩, employing the lowering diacritic (U+031E, a combining down tack below the symbol), which indicates a realization lowered toward the open-mid position closer to [ɛ].[23] This notation is particularly useful in narrow transcriptions where the vowel's quality deviates slightly from the standard close-mid height due to phonetic context or speaker variation.Conversely, the raised variant is transcribed as ⟨ɛ̝⟩, utilizing the raising diacritic (U+031D, a combining up tack below the open-mid symbol [ɛ]), to represent a quality elevated toward the close-mid position nearer to .[23] This adjustment allows phoneticians to capture subtle elevations in vowel height without introducing entirely new symbols.These diacritic variants find application in narrow phonetic transcriptions of dialects and idiolects, where fine-grained distinctions in vowel realization are necessary. For instance, in certain accents of English, the vowel in the lexical set "DRESS" (as in "bed") may be transcribed as [ɛ̝] to reflect a raised quality approaching close-mid in some speakers.[23]The standardization of such diacritics for mid vowels stems from revisions to the IPA chart at the 1989 Kiel Convention, which addressed ambiguities in height specification by recognizing four principal degrees of vowel height—open, open-mid, close-mid, and close—while designating "mid" as a subsidiary category without dedicated symbols.[24] The convention endorsed the use of lowering and raising diacritics on existing symbols like and [ɛ] to denote intermediate positions, ensuring consistency in transcribing vowels that fall between established cardinal qualities on the vowel quadrilateral.[24]
Articulation and Acoustics
Production Mechanism
The production of the mid front unrounded vowel involves a specific configuration of the tongue within the oral cavity. The body of the tongue is raised to a mid-height position, with its highest point positioned in the front of the mouth, just below the hard palate, while the front portion advances toward the alveolar ridge without contacting it. Additionally, the lateral edges of the tongue are lowered to enlarge the oral space and facilitate resonance.[16][25]The jaw is moderately lowered to accommodate the tongue's elevation, creating an intermediate opening in the vocal tract that is wider than for consonants but not as open as for low vowels. The lips are spread laterally in a neutral, unrounded position, avoiding any protrusion or rounding that would alter the front quality. The soft palate, or velum, is raised to seal the nasal cavity, directing airflow exclusively through the oral tract for non-nasal resonance.[16][26]This vowel is produced using pulmonic egressive airflow, where air from the lungs is expelled through the vocal tract without interruption or turbulence. Voicing is achieved through vibration of the vocal folds in a modal register, producing a periodic sound wave with fundamental frequency typically in the range of adult male or female speech norms.Articulatory studies using X-ray cineradiography in the mid-20th century, such as those examining vowels in languages with a clear mid front unrounded phoneme like French, have confirmed this front mid tongue positioning, showing consistent advancement of the tongue blade and body without significant pharyngeal constriction.[26]
Formant Characteristics
The mid front unrounded vowel, represented as in the International Phonetic Alphabet, exhibits characteristic formant frequencies that reflect its articulatory position: a first formant (F1) typically ranging from 400 to 500 Hz, indicative of its mid height; a second formant (F2) around 1800 to 2200 Hz, signaling its front tongue position; and a third formant (F3) often higher, around 2500 to 3000 Hz, contributing to the perceptual clarity of its unrounded quality.[6][27] These values can vary based on language and speaker, as seen in acoustic analyses of native productions; for instance, in Spanish, stressed tokens of /e/ show mean F1 at 577 Hz and F2 at 1922 Hz, while unstressed tokens have slightly lower values of F1 at 518 Hz and F2 at 1748 Hz.[28]In the spectral envelope, the mid front unrounded vowel displays a lower F1 compared to open vowels like (F1 often exceeding 700 Hz), positioning it acoustically between high front vowels such as (F1 below 300 Hz) and more open front vowels; its F2 remains elevated relative to back vowels like (F2 below 1000 Hz), creating a distinct front resonance peak.[6] Formant characteristics are measured primarily from wideband spectrograms, where dark bands represent formant tracks, using software like Praat for linear predictive coding (LPC) analysis to estimate frequencies at the vowel's steady-state midpoint, avoiding coarticulatory influences from adjacent consonants.[29][30] Variations arise with speaker gender and age due to vocal tract length differences: females and children generally produce higher formants than males, as documented in large-scale databases. For example, in American English productions of the related open-mid /ɛ/ (a near-variant of ), Hillenbrand et al. (1995) reported the following mean values across 139 speakers:
Group
F1 (Hz)
F2 (Hz)
F3 (Hz)
Males
580
1799
2605
Females
731
2058
2979
Children
749
2267
3310
These measurements, derived from citation-form words analyzed via LPC and spectrographic verification, underscore the vowel's acoustic stability while highlighting speaker-specific scaling.[31]
Occurrence in Languages
Phonemic Examples
The mid front unrounded vowel /e/ functions as a phoneme in numerous languages, where it contrasts with other vowels to distinguish meaning. For instance, in Spanish, /e/ contrasts with /a/ in the minimal pair mesa [ˈme.sa] 'table' versus masa [ˈma.sa] 'dough'.[33]This vowel appears phonemically in languages worldwide, including Austroasiatic, Indo-European, Japonic, Niger-Congo, and Turkic families. In Basque, /e/ is one of five monophthongal vowels and occurs in words like euskara [eus.ka.ɾa] 'Basque language'.[34] In Japanese, /e/ is part of the five-vowel system and is realized in terms like sensei [seɴseː] 'teacher'.[35] Kensiu, an Aslian language, includes /e/ among its 14 oral vowels, contrasting in height and backness with nearby qualities like /ę/ and /ɛ/.[36]Further examples include underrepresented languages such as Breton, where /e/ appears in enez [ẽː.nɛs] 'island', and Yoruba, which distinguishes /e/ (mid) from /ɛ/ (open-mid, written ẹ).[37][38] In orthographies using Latin script, /e/ is typically represented as ⟨e⟩, as in the examples above; in Cyrillic-based systems influenced by Slavic languages, it may appear as ⟨е⟩ in Russian.
Allophonic Occurrences
The mid front unrounded vowel frequently appears as an allophonic variant of lower front vowels, particularly through raising processes conditioned by adjacent consonants or prosodic position. In many dialects of English, the low front /æ/ (as in the TRAP lexical set) is realized as a raised -like variant before nasal consonants, a phenomenon known as pre-nasal raising. This allophony is widespread in North American varieties, where the tongue body elevates significantly, bringing the realization closer to mid height without merging with phonemic /e/. For instance, words like "man" [mæ̝n] or "can" [kæ̝n] exhibit this raised form, contrasting with non-pre-nasal contexts like "mat" [mæt].[39] Similarly, the open-mid /ɛ/ (DRESS lexical set) raises toward [e̝] in certain dialects, such as those in the Northern Cities Shift region, where it approaches mid height in stressed positions before certain consonants.[40]Conditioning factors for allophony often involve phonetic environments that promote vowel raising, such as proximity to high or nasal consonants, or reduced stress, observed across numerous languages. In Brazilian Portuguese, pre-nasal /ɛ/ raises to (with nasalization), as in "pão" [pɐ̃w̃] influencing nearby vowels or "bem" [bẽj̃], where the mid realization serves as a non-contrastive variant of the phonemic open-mid vowel. German exhibits similar raising of /ɛ/ to in unstressed syllables or before nasals, as in "Bett" [bɛt] versus reduced forms in compounds like "Bettdecke" [ˈbɛtˌdɛkə] with elevated unstressed vowels. In Italian, unstressed /ɛ/ often raises to in rapid speech, particularly in northern dialects, as seen in words like "letto" [ˈlɛtːo] where secondary syllables approach mid height. Japanese /e/ has contextual variants approaching from slightly lower realizations before high vowels or in compound words, though minimal; Korean /ɛ/ raises toward before /j/ or in diphthongs, as in "mae" [mɛ] versus [me] in connected speech. Turkish includes as a harmonic variant in suffixes matching front stems, non-contrastively determined by stem vowels. These patterns appear in languages including English, Portuguese, German, Italian, Japanese, Korean, and Turkish, where raising serves non-contrastive roles without altering meaning.[41][42]In vowel harmony systems, often emerges non-phonemically as part of assimilatory processes, where its appearance is predictable based on stem features rather than contrast. In Turkish, front vowel harmony requires suffixes like the locative -de to surface as [de] after front stem vowels (e.g., "ev-de" [evde] 'in the house'), but as [da] after back vowels, making the mid front a non-contrastive harmonic variant tied to the system's front/back feature agreement. Similar non-phonemic distributions occur in other harmony languages, where fills mid slots without independent phonemic status in the paradigm.[42]Recent ultrasound studies highlight the gradient nature of such allophony, revealing incomplete or variable realizations rather than discrete categories. In English, Mielke et al. (2017) used ultrasound imaging to measure tongue dorsum height in /æ/ production across dialects, finding pre-nasal raising as a continuous gradient (with F1 lowering by 200-400 Hz on average) rather than a categorical shift to , varying by speaker and regional factors like the Northern Cities Shift. This incompleteness underscores how allophonic emerges probabilistically, influenced by coarticulatory overlap with nasals, as confirmed in 2020s cross-dialect analyses showing similar variability in pre-nasal environments across UK and North American varieties.[39][43]
Phonological Variations
Dialectal Differences
In Scottish English, the mid front unrounded vowel corresponding to the DRESS lexical set (as in "bed") is typically realized as a raised variant [ɛ~e̝], closer to close-mid height than in other varieties. This contrasts with General American English, where the same vowel is lowered to an open-mid [ɛ].In Spanish, the phonemic /e/ is generally realized closer to cardinal in Peninsular varieties, reflecting a more tense articulation.[44] In Caribbean dialects, however, /e/ often undergoes diphthongization to [ei], particularly in open syllables or before certain consonants, contributing to a more dynamic vowel quality influenced by Andalusian substrate features.[45]Other languages exhibit subtler regional shifts in the mid front unrounded vowel. Similarly, Basque dialects display height variations, with central varieties raising /e/ slightly higher than peripheral ones in certain phonological contexts.[46]These dialectal differences are often shaped by prosodic factors, such as stress and intonation patterns that alter vowelduration and height, as well as contact with neighboring languages leading to substrate influences. Dialect atlases, including the Atlas Linguistique de la France (ALF), document analogous variations in French-influenced regions, where prosody and bilingual contact cause shifts in /e/ realization.
Relations to Other Vowels
The mid front unrounded vowel differs from the close front unrounded vowel primarily in tongue height, with featuring a lower, more relaxed tongue position that produces a relatively open timbre compared to the higher, more constricted articulation of . This distinction places midway between high and low vowels in the front region of the oral cavity.[15] In contrast to the open front unrounded vowel , involves a higher tongue arch and reduced jaw opening, resulting in less acoustic openness and a mid-level formant structure.[16]The rounded counterpart to , the mid front rounded vowel [ø], introduces lip rounding that alters the vowel's resonance and plays a key role in phonological processes like vowel harmony. In Hungarian, functions as a neutral or transparent vowel in backness harmony, allowing harmony to propagate past it without triggering rounding, whereas [ø] actively conditions front rounded suffixes, enforcing stricter assimilation rules in suffix selection.[47] This contrast underscores how unrounding in permits greater flexibility in harmony systems compared to the more constraining effects of [ø].[48]In Germanic languages, the mid front unrounded vowel exhibits a tense-lax distinction, where the tense (typically long) is articulated with greater muscular tension, higher tongue position, and longer duration than the lax [ɛ] (short), leading to more peripheral formants in . This opposition is phonemically contrastive in languages like German, where [eː] and [ɛ] distinguish minimal pairs, but merger tendencies appear in some modern varieties, such as reduced distinctions in certain Dutch dialects or informal American English realizations of near-mid vowels.[49]Historically, the mid front unrounded vowel traces evolutionary paths from Proto-Indo-European (PIE) *e, which developed into mid vowels across Indo-European branches through regular sound changes. In the Germanic lineage leading to English, PIE *e yielded Proto-Germanic *e, preserved as Old English /e/, which underwent chain shifts; short variants often lowered to /ɛ/ in Middle English, while long /eː/ raised to /iː/ during the Great Vowel Shift (c. 1400–1700), reshaping the front vowel system and contributing to modern English outcomes like the DRESS vowel /ɛ/.[50] These shifts illustrate how participated in broader vowel rotations, influencing contrasts with neighboring vowels in descendant languages.[51]