Definition:
An open vowel (also called a low vowel) is a vowel produced with the tongue positioned as low as possible in the oral cavity, creating maximum space between the tongue and the roof of the mouth. Open vowels sit at the bottom of the IPA vowel chart and include /a/ (open central), /æ/ (near-open front), /ɑ/ (open back unrounded), and /ɒ/ (open back rounded).
In-Depth Explanation
Open vowels have the highest first formant frequencies (F1) of any vowels — the acoustic fingerprint of a low tongue position and open jaw. They are the loudest and most sonorous vowels, which is why they tend to occur at syllable peaks and are cross-linguistically the most common vowel class.
| Front | Central | Back | |
|---|---|---|---|
| Near-open | /æ/ (cat) | /ɐ/ (German) | — |
| Open | — | /a/ (Japanese あ) | /ɑ/ (father), /ɒ/ (Br. lot) |
Every known language has at least one open vowel — it’s the most universal vowel category.
Open vowels in Japanese:
Japanese has one open vowel: /a/ (あ). It is an open central (or slightly front-of-center) unrounded vowel. It corresponds roughly to the vowel in Italian “casa” or Spanish “padre” — a clean, pure /a/ without the complexities of English’s multiple low vowels (/æ/, /ɑ/, /ʌ/).
English speakers often have trouble with Japanese /a/ not because of the sound itself but because English maps several different vowels to this region — “cat” /æ/, “father” /ɑ/, “cup” /ʌ/, “about” /ə/ — and English speakers may unconsciously substitute one of these. Japanese /a/ is none of them; it sits centrally. The Italian/Spanish /a/ is the best reference point.
Because /a/ is the most open and sonorous vowel, it is never devoiced in Japanese (unlike close vowels /i/ and /ɯ/ which frequently devoice). It always gets full voicing and clear production.
Related Terms
See Also
Research
- Ladefoged, P., & Johnson, K. (2014). A Course in Phonetics (7th ed.). Cengage Learning. — Vowel height classification and acoustic correlates.