Central vowel

A central vowel is a special vowel sound made when the tongue is in the middle of the mouth. It is not too far forward and not too far back.

The word "central" talks about this middle place for the tongue. This is called the backness dimension. It is different from another idea called "mid." "Mid" talks about how high or low the tongue is. This is called the height dimension. So, a central vowel is about where the tongue is from side to side, not how high or low it is.

In a big study of sounds from many languages, two central vowel sounds are very common. These sounds are shown with special symbols: [ə] and [ɨ]. They appear in many languages around the world. Other central vowel sounds exist too, but they are used less often.

Articulation and acoustics

Central vowels are made by putting the tongue in the middle. It is not too far forward and not too far back. The middle position can change a little in different languages.

The International Phonetic Alphabet (IPA) has a chart that shows different vowel sounds. On this chart, the horizontal line shows how far forward or backward the tongue is, and the vertical line shows how high or low the tongue is. Central vowels are in the middle of the horizontal line.

IPA transcription

On the International Phonetic Alphabet vowel chart, central vowels are in the middle column between front and back vowels. We can use special marks to show small changes in how these vowels sound.

The central vowels that have their own special symbols include:

• close central unrounded vowel [ɨ]
• close central rounded vowel [ʉ]
• close-mid central unrounded vowel [ɘ] (also written as ⟨ë⟩)
• close-mid central rounded vowel [ɵ] (also written as ⟨ö⟩)
• mid central vowel [ə]
• open-mid central unrounded vowel [ɜ] (also written as ⟨ɛ̈⟩)
• open-mid central rounded vowel [ɞ] (also written as ⟨ɔ̈⟩)
• near-open central vowel [ɐ]

Different places may use these symbols in slightly different ways. For example, some use [ɜ] for a strong central vowel and [ə] for a weaker one, while others might use [ə] for a fully strong central vowel too.

Central vowel sounds that do not have their own special symbols are usually shown with marks that indicate small changes. Some examples are:

• near-close central unrounded vowel [ɨ̞], [ɪ̈], [ɪ̠] or [ɘ̝]
• near-close central rounded vowel [ʉ̞], [ʊ̈], [ʊ̟] or [ɵ̝]
• near-close central vowel with a special rounding (as in some Swedish sounds) might be written as [ʏ̈]
• mid central unrounded vowel [ɘ̞] or [ɜ̝] (often just written as ⟨ə⟩)
• mid central rounded vowel [ɵ̞] or [ɞ̝] (often just written as ⟨ɵ⟩)
• open central unrounded vowel [ä] (sometimes written as ⟨ä⟩)
• open central rounded vowel [ɒ̈]