Approximant

Approximants are special kinds of speech sounds used in language. They happen when parts of the mouth, called articulators, move close together but not quite close enough to make a tight narrow space. This means they are not as strong as sounds called fricatives, which make a noisy, turbulent airflow, and they are not as open as vowels, which have no turbulence at all.

Approximants include sounds like the "r" sound in the word "rest" and sounds called semivowels, such as the "y" sound in "yes" and the "w" sound in "west". There are also lateral approximants, like the "l" sound in "less". These sounds are important in speech because they help give words their unique sounds and make speaking easier and more smooth.

Terminology

Before Peter Ladefoged introduced the term approximant in the 1960s, people used words like frictionless continuant and semivowel to talk about certain sounds.

In phonology, an approximant is a special feature that includes all sonorants except nasals. This group also includes vowels, taps, and trills.

Semivowels

Main article: Semivowel

Some approximants sound like vowels and are called semivowels or glides. These sounds don’t form a syllable on their own but are very similar to vowels. For example, in English, the “y” sound in yes and the “w” sound in west are semivowels.

Languages often switch between vowels and semivowels depending on the word or its meaning. For instance, in English, the ending of words can change whether a sound acts like a vowel or a semivowel. This relationship helps explain why certain sounds change in different languages.

Approximants versus fricatives

See also: Spirant approximant

Approximants are different from fricatives because they need less precision to make the sound. When we stress approximants, they can sound a bit like fricatives, with a slightly turbulent airstream. For example, in Spanish, the word ayuda meaning 'help' has a sound that can change depending on how strongly it is pronounced.

In some parts of the mouth, languages do not make a clear difference between voiced fricatives and approximants. Because of this, special symbols are used to represent these sounds, sometimes with extra marks to show the difference.

Central approximants

Approximants are speech sounds made when parts of the mouth come close together but not so close that they create friction, like when we say "red" or "yes". These sounds are softer than fricatives and closer to vowels.

Some common central approximants include the labiodental approximant [ʋ], the alveolar & post-alveolar approximants [ɹ], the retroflex approximant [ɻ], the palatal approximant [j], and the velar approximant [ɰ].

Glottal approximants

Glottal approximants are special sounds made using the larynx without a specific shape for the rest of the mouth. They change based on the sounds around them.

• voiceless glottal approximant [h̞]
• breathy-voiced glottal approximant [ɦ̞]
• creaky-voiced glottal approximant [˷]

Lateral approximants

In lateral approximants, the tongue touches the roof of the mouth in the middle, but the sides of the tongue move close to the teeth, letting air flow freely around them. This creates a smooth sound without friction.

Some common lateral approximants include:

• voiced alveolar lateral approximant [l]
• retroflex lateral approximant [ɭ]
• alveolo-palatal lateral approximant [l̠ʲ] or [ʎ̟] (usually transcribed ⟨ȴ⟩)
• voiced palatal lateral approximant [ʎ]
• velar lateral approximant [ʟ]
• uvular lateral approximant [ʟ̠]

Coarticulated approximants

Coarticulated approximants are special sounds made when two parts of the mouth work together. One example is the labial–palatal approximant [ɥ], which is like a consonantal version of the sound y. Another is the labial–velar approximant [w], similar to a consonantal version of the sound u. These sounds show how different areas of the mouth can combine to create unique speech sounds.

Voiceless approximants

Some people have debated whether voiceless approximants can really exist. One reason for this is that without voice, airflow might become turbulent, making the sound more like a fricative instead of an approximant. However, recent studies show differences in how air moves when making these sounds. Voiced approximants usually have smooth airflow, while voiceless ones can sometimes have a bit of turbulence, making them hard to distinguish from fricatives.

Voiceless approximants are not commonly found in languages and are often confused with fricatives. Some researchers argue that if a sound is truly an approximant, it should be quiet without voice or friction, which makes the idea of a voiceless approximant tricky. Examples of languages where these sounds appear include Burmese, Standard Tibetan, Navajo, and Zulu. In Western American English, voiceless lateral approximants can appear after certain sounds, like the "k" sound.