Roundedness

In phonetics, vowel roundedness is about how your lips are shaped when you make vowel sounds. It means your lips can be rounded or spread apart while talking. Rounded vowels are shown on the right side of the International Phonetic Alphabet chart. Unrounded vowels are on the left. For example, in English, the sound in "too" is rounded. The sound in "see" has spread lips.

Different languages use rounded and unrounded vowels in many ways. Many languages have front vowels with spread lips and back vowels with rounded lips. But some languages, like French and German, use both rounded and unrounded sounds for front vowels. Others, such as Vietnamese, do this for back vowels. And Turkish uses both for front and back vowels.

The way your lips are shaped can change how a vowel sounds. When making a rounded back vowel, the lips form a small, round opening. Unrounded vowels are made with spread or relaxed lips. This difference helps our ears tell vowels apart. One language, Alekano, only uses unrounded vowels.

Typology

Vowel roundedness is about how your lips shape when you make vowel sounds. In the International Phonetic Alphabet, rounded vowels are on the right, and unrounded vowels are on the left. For example, the vowel u is closely rounded, while i is fully spread.

The height of the vowel changes how much the lips are rounded or spread. Open vowels, like a, usually have a neutral lip position. Back vowels range from neutral to closely rounded. Front vowels are usually unrounded but can have different amounts of spreading.

Transcription

When we write sounds for vowels, we can use special symbols to show the shape of the lips. Small letters above the main letter can tell us if the lips are pushed out or pulled in. There are also old symbols for different kinds of rounding.

We can use special marks to show central vowels, which are sounds made in the middle of the mouth. These marks help make the sound clearer. The tables below show different ways to write these sounds using these special symbols.

Main article: nonstandard symbols in the IPA

Rounding and labialization

When we make some vowel sounds, we often round our lips. This rounding can change the sounds of nearby consonants.

For example, in Vietnamese, after rounded vowel sounds like /u/ and /o/, the consonant sounds /k/ and /ŋ/ change a little. The lips stay rounded when we say these consonants.

In some languages, such as the Northwest Caucasian languages spoken in southern Russia and Georgia, and Arrernte from central Australia, rounded vowels changed nearby consonants a lot. This created new consonant sounds with rounded lips. The vowels themselves then stopped being rounded.

Roundedness in English

In some types of British English, like the Cardiff dialect, Geordie, and Port Talbot English, as well as in General South African English and New Zealand English, some vowel sounds change based on how the lips are shaped. This makes pairs of sounds that are different but close together.

For example, in Standard Southern British English and Western Pennsylvania English, words like nut and not sound different mostly because of how the lips are shaped. These differences can also be affected by other things like how high or shaped the mouth is. In Scottish English, these sounds can change in small ways, making some words sound quite different depending on the shape of the lips.