Nasal vowel

A nasal vowel is a special kind of vowel sound made when air flows out through both the nose and the mouth at the same time. This happens because the soft palate, a part of the roof of the mouth, lowers to let air escape through the nose. For example, in French, there are vowel sounds like /ɑ̃/^ⓘ, and in Amoy, there are sounds like [ɛ̃]. These are different from regular vowel sounds, which are called oral vowels because they are made without any air coming out of the nose.

In many languages, vowels next to certain letters, like “m” or “n,” can sound a little bit nasal. This happens naturally when the shape of the mouth changes to make the nasal sound. In English, for example, the vowel in the word hand is affected by the “n” that comes after it, but English does not treat nasal and oral vowels as completely different sounds.

However, some languages, like French and Portuguese, treat nasal and oral vowels as very different. In these languages, changing a vowel from oral to nasal can change the meaning of a word completely. For example, in French, beau /bo/ means “beautiful,” while bon /bɔ̃/ means “good.” In Portuguese, mau /ˈmaw/ means “bad,” and mão /ˈmɐ̃w̃/ means “hand.” Even though English borrows some words from French that have nasal vowels, like croissant, English speakers usually do not make the nasal sound as strongly as people in France or Portugal do.

Influence on vowel height

When a sound like "n" or "m" comes before a vowel, it can change how the vowel sounds. This change can make the vowel sound a little higher or lower, depending on the language.

Some languages change high vowels more, like Chamorro, while others change low vowels more, like Thai. Most languages change all vowels this way, but not always in the same way.

Degree of nasalization

Some languages, like Palantla Chinantec, have vowels that sound a little bit nasal and vowels that sound very nasal. People write these differences using special symbols above the vowel letters. One way is to use a tilde symbol, like ⟨ẽ⟩ for a lightly nasal vowel and ⟨ẽ̃⟩ for a heavily nasal vowel. Another way is to combine the tilde with something called an ogonek, like ⟨ẽ⟩ vs ⟨ę̃⟩. The ogonek helps avoid mixing up these symbols with tone marks used in some languages.

Origin

Rodney Sampson described how nasal vowels developed in modern French through three main stages. During the time of Old French, vowels started to sound nasal because of sounds that came before them. In Middle French, the nasal sounds became less clear. By the time French became what we know today, those special sounds disappeared completely.

Many languages around the world develop nasal vowels when certain sounds change over time. This happens especially when sounds at the start of words become simpler.

Orthography

Languages that use the Latin script can show nasal vowels by adding a silent n or m at the end of a word, like in French, Portuguese, and Yoruba.

Other times, special marks called diacritics are used. In the International Phonetic Alphabet, a tilde (~) is placed above the vowel symbol. Some languages, like Portuguese, also use the tilde, while others, such as Paraguayan Guaraní, use a diaeresis (¨). Some languages use a hook under the letter, called an ogonek, like in Polish. The Pe̍h-ōe-jī system for Taiwanese Hokkien uses a small n above the vowel. In old Icelandic texts, a dot above the vowel shows nasalization.

Languages

Many languages around the world use sounds where air comes out through the nose while making a vowel sound. Some of these languages include French, Portuguese, Japanese, and Bengali. Others are Guaraní, Haitian Creole, Navajo, and Scottish Gaelic. This special way of making sounds is called a nasal vowel.