Vowel

A vowel (/ˈvaʊ.əl/) is a speech sound made without any blockage in the vocal tract. Vowels are one of the two main types of speech sounds, the other being consonants. Vowels can change in how they sound, how loud they are, and how long they last. They are usually made with voice and help give meaning to words through things like tone, intonation, and stress. The middle part, or "center," of a word, called a syllable, often includes a vowel sound, though this is not always the case.

The word vowel comes from the Latin word vocalis, which means "vocal" or relating to the voice. In English, the word vowel is used for both the sounds we make and the letters that stand for those sounds: ⟨a⟩, ⟨e⟩, ⟨i⟩, ⟨o⟩, ⟨u⟩, and sometimes ⟨y⟩ and ⟨w⟩.

Definition

A vowel is a sound made when speaking without closing the mouth tightly. There are two ways to think about what a vowel is:

• In one way, a vowel is a sound like the "ah" in "father" or the "oh" in "go," made by letting air flow freely through the mouth. This is different from sounds like "sh" in "shoe," where the mouth is more closed.

• In another way, a vowel is the main sound in a word part called a syllable, like the "a" in "father." Some sounds that feel like vowels can act like consonants when they appear at the start of a syllable, such as the "y" in "yes."

Articulation

See also: Articulatory phonetics

Vowels are sounds made without blocking the air flow in the throat. They are different from consonants, which are made by partly blocking the air flow. Vowels can change in how high or low they sound, and in how far forward or backward they are made in the mouth.

Vowels can also change depending on how the lips are shaped. Sometimes the lips are rounded, and sometimes they are not. This helps to make different vowel sounds.

Vowels can also be affected by whether air flows through the nose or just the mouth. This can change the sound of the vowel a little bit.

Some languages have special vowels that are only used when a word is not stressed. These vowels are often shorter and lighter than the main vowels in a word.

Acoustics

See also: Acoustic phonetics

The way vowels sound is studied using special tools that show sound waves. These tools help us see how the shape of our mouth and tongue changes the sound. When we make different vowels, our mouth acts like a resonator, and this changes the sound in specific ways.

We can measure these sound changes using something called formants. The first formant, written as F₁, tells us how high or low the vowel sound is. The second formant, F₂, tells us how far forward or backward in the mouth the sound is made. By looking at these formants, we can see and compare the qualities of different vowel sounds.

Prosody and intonation

Vowels can change based on how we say them, which is called prosody. This includes things like how high or low the pitch is, how loud we speak, and how long the sound lasts. These changes usually happen within a group of sounds called a syllable, not just the vowel alone.

For example, in the word "cat," the vowel carries the pitch. Loudness is linked to stress in a word, and it affects the whole syllable, not just the vowel. Vowel length can differ between languages. Some languages, like Japanese, Finnish, Hungarian, Arabic, and Latin, have short and long vowels. Vowels can also get longer when we stress a syllable or speak more slowly.

Monophthongs, diphthongs, triphthongs

Main articles: Monophthong, Diphthong, Triphthong, and Semivowel

A vowel sound that stays the same all the way through is called a monophthong. These are sometimes called "pure" or "stable" vowels. A vowel sound that changes from one sound to another is called a diphthong, and a vowel sound that changes through three sounds is a triphthong.

All languages have monophthongs, and many have diphthongs, but triphthongs or vowel sounds with even more changes are less common. English has all three types: the vowel sound in hit is a monophthong /ɪ/, the vowel sound in boy is a diphthong /ɔɪ/, and the vowel sounds in flower, /aʊər/, can form a triphthong or two separate sounds, depending on how you say it.

Written vowels

Main article: Writing system

The word "vowel" is often used to describe the letters that stand for vowel sounds in a language’s writing system, especially in languages that use an alphabet. In systems based on the Latin alphabet, letters like ⟨a⟩, ⟨e⟩, ⟨i⟩, ⟨o⟩, ⟨u⟩, ⟨y⟩, and ⟨w⟩ can represent vowels. However, these letters don’t always stand for vowels in every language, or even in every word of a single language. Sometimes, letters usually used for consonants can also show vowel sounds, or a group of letters can work together to make a vowel, like ⟨igh⟩ in “thigh” or ⟨x⟩ in “x-ray”.

Some languages add special marks to vowel letters or create new letters to show all their vowel sounds. For example, Swedish uses ⟨ä⟩, and some Scandinavian languages use letters like ⟨æ⟩ or ⟨ø⟩. The International Phonetic Alphabet has many symbols to show all the different vowel sounds possible.

Certain writing systems, like the Hebrew alphabet and the Arabic alphabet, often don’t write all the vowels. These are called abjads. Even though it might seem tricky, these systems can still help us understand words. For example, in English, a word like dd could mean many different things. Special systems, like the Masoretes’ way of noting vowels in Hebrew, help make sure everyone reads words the right way.

Audio samples

This section includes audio samples to help you hear how vowels sound. Listening to these can be fun and helpful for learning pronunciation. The samples show the different qualities of vowel sounds, which can vary in how they are made and heard.

Systems

The importance of vowels in separating one word from another varies between languages. Almost all languages have at least three main vowel sounds, often /i/, /a/, and /u/. Some languages have even fewer, with just two vowel sounds.

How many vowels a language has depends on how you count them. Some languages have many vowel sounds, while others have just a few. For example, Danish has around eleven to thirteen short vowels, while Spanish has only five main vowel sounds.

One very common vowel is [a̠]; most languages have at least one similar sound. In English, there are several sounds like this, but not the exact [a]. Some languages, like Tagalog and Cebuano, use a different sound instead of [a].

Vowels help us tell words apart in most languages. For example, in English, "man" becomes "men" when it’s plural, but "moon" is a completely different word.