Definition:
A close vowel (also called a high vowel) is a vowel produced with the tongue raised as high as possible in the oral cavity without creating the constriction that would make it a consonant. Close vowels sit at the top of the IPA vowel chart. The most common close vowels across languages are /i/ (close front unrounded) and /u/ (close back rounded).
In-Depth Explanation
The IPA uses the term “close” (tongue close to the palate) while American English phonetics tradition uses “high” (tongue in a high position). They describe the same thing.
| Front | Central | Back | |
|---|---|---|---|
| Close | /i/ (see) | /ɨ/ (Russian ы) | /ɯ/ (Jpn う), /u/ (food) |
| Near-close | /ɪ/ (sit) | /ʊ/ (foot) |
Close vowels have several distinctive properties:
- Highest tongue position of any vowels — one step higher and the constriction would produce a glide or fricative
- Lowest first formant (F1) — this is the acoustic correlate of tongue height
- Most susceptible to consonant-like behavior — in rapid speech, close vowels can become glides (/i/ → [j], /u/ → [w]) or be devoiced
Close vowels in Japanese:
Japanese has two close vowels:
- /i/ — Close front unrounded. Similar to English “see” but shorter and without diphthongal glide. Found in い and as part of きしちにひみり etc.
- /ɯ/ — Close back unrounded. Unlike English /u/ (which is close back rounded). Found in う and as part of くすつぬふむる etc.
Both Japanese close vowels undergo devoicing in predictable environments: between voiceless consonants, or after a voiceless consonant at the end of an utterance. This is why です sounds like “des” (not “desu”) and すき sounds like “ski” (not “suki”) in natural Tokyo Japanese. The vowel is technically produced but without vocal fold vibration — it becomes a whispered or silent vowel.
This devoicing pattern is nearly automatic for native speakers and is one of the features that gives Japanese its characteristic rhythmic quality. It’s also a useful litmus test for naturalness in learner pronunciation.
Related Terms
See Also
Research
- Ladefoged, P., & Johnson, K. (2014). A Course in Phonetics (7th ed.). Cengage Learning. — Standard reference for vowel height classification.
- Vance, T. J. (2008). The Sounds of Japanese. Cambridge University Press. — Detailed coverage of Japanese close vowels and their devoicing patterns.