Phonetics 2 - Vowels

Hi, I'm Taylor and welcome to Crash Course Linguistics!

In the last video we learned about the International Phonetic Alphabet, and how we can represent every sound in human speech with exactly one symbol.

We also learned about consonants, like [p], [s], and [n], which are sounds that involve closing the vocal tract in some way.

These sounds can be arranged into a chart based on whether they’re voiced or voiceless and the manner and place of articulation.

But there aren't any spoken languages that only have consonants.

In this episode, we’ll continue with phonetics, looking at vowels and how they’re represented in the IPA!

[THEME MUSIC ANIMATION] We can think of vowels as the sounds that we can sing with our mouths open.

aaaaaah, ooooooh, eeeeeee.

We can sing them this way because, in phonetic terms, vowels are made without closing the vocal tract just by subtly changing the shape of the tongue so that the air comes out differently instead.

English has five vowel letters in the alphabet...maybe six if we count Y.

But we have way more vowel sounds than that.

Different varieties of English have between 12 and 21 vowel sounds.

And if someone is speaking with a different accent than yours, you’ve probably heard it in the way they pronounce their vowels.

Some varieties of English pronounce these two words the same, and some pronounce them differently.

We can hear fourteen vowel sounds shared by most varieties of English in this old-timey sentence: Who would know aught of art, must learn, act, and then take his ease.

But five or six vowel letters and way more than five vowel sounds?

No matter what your accent, that spells trouble.

That's where the International Phonetic Alphabet comes in, so we can write all the vowels in any spoken language clearly and unambiguously.

We can start by figuring out what vowel sounds we need to represent.

To do this, we'll look at which parts of the mouth are involved in making vowels.

In other words, we'll map out the vowel space.

Let's make the sound [iiiiii] — go ahead and make it with me, because it's going to be a lot easier for you to feel it inside your mouth than to see it inside mine.

So let’s start with [i] and gradually move the sound all the way down to [æ].

[iiiieeeeeɛɛɛɛɛæææææ].

We can slowly move from one vowel sound to another and there are no fixed lines between them.

This is very different from what we saw for consonants, with their distinct categories based on whether the lips touch each other, or the tongue touches a point on the roof of the mouth, and so on.

Vowels aren’t categorical like this.

The gradual movement between them means that differences are gradient, so we need a different approach to describing vowels.

Take the sounds [i] and [æ].

The difference between them is how open your mouth is and how close your tongue is to the roof of your mouth.

For [i] the tongue is very high, close to the roof of the mouth, and the jaw is more closed, while for [æ] the jaw is open and the tongue is low.

In the IPA we write [i] with this symbol and [æ] with this one.

Because of where your tongue is when making them, [i] is a high vowel and [æ] is a low vowel.

Linguists also sometimes call [i] a close vowel and [æ] an open vowel, based on whether your jaw is more open or more closed.

High/close and low/open mean the same thing.

Let’s try moving from [æ] to something like a full open-mouth doctor-checking-your-tonsils [ɑ].

[æææææɐɐɐɐɑɑɑɑ] Your tongue stays low but it moves further back in your mouth.

[i] and [æ] are front vowels and [ɑ] is a back vowel.

We now have two features: how high your tongue is, and how far back your tongue is.

We still don’t have anything that’s high and back.

The sound [u] fits this description.

Let's go from [ɑ] to [u]: [ɑɑɑɑɑɑooooouuuuu].

Hmm, something else happened on the way from [ɑ] to [u], and this one you can see on my face!

My lips became rounded as my tongue moved backward to make an [u].

We can also notice this by going from [u] to [i].

It's common in many of the world's languages, including English, for sounds at the front of the mouth, like [i], to be unrounded and sounds at the back of the mouth, like [u], to be rounded, but that's not always the case.

The sound [y] is in the front of the mouth like [i] but rounded like [u].

You can move between [i] and [y] by keeping your tongue and jaw still and just rounding and unrounding your lips [iiiiyyyyiiiiyyyy].

This sound is found in the French word "tu" as well as in German, Turkish, and Mandarin.

There’s also an unrounded partner of our high back rounded [u], [ɯ].

This vowel is found in Vietnamese, Tamil and an extremely Californian pronunciation of "dude".

We now have three features: How high or low the tongue is, Whether the tongue is back or front, and and whether the lips are rounded.

We can use these three features to fill in more vowels in the vowel space.

For example, [eeeeee] is produced with the tongue midway between [iiiii] and [æææ], so that makes it mid front and rounded, instead of high or low.

And [o] is produced midway between [u] and [ɑ], with the lips rounded, so it's a mid back rounded vowel.

If we go right into the center of the vowel space, the vowel that's neither high nor low, neither front nor back, we get the sound [ə].

Linguists are especially interested in this sound, so it has a special name.

It's called schwa, and it’s the most common vowel sound to pronounce in English.

It shows up in the unstressed parts of words like ‘about’, ‘potato’ and ‘petition’.

So far we’ve been talking about sounds like [iiii] or [uuuu] where your tongue stays in the same position the whole time.

But now let's try the sound [oi].

Let's make it really slowly: [ooooooɪɪɪɪɪiiiii].

Your tongue starts in the position for the vowel [o] and ends in the position for the vowel [i], so that's how we write it — by combining two vowel symbols in a row.

Two vowels said together like [oi] is known as a diphthong.

The full IPA chart doesn’t typically list diphthongs because you can make them out of any two vowels.

Other common diphthongs in English include [aɪ] and [aʊ].

Both of these start with the [a] sound, but one goes forward towards [i] — [aaaaaiiiii].

The other goes backwards toward [u] — [aaaaauuuu].

But, again, in principle, we could go from any vowel to any other vowel.

You can pause this video and try some other diphthongs yourself!

Anyway, like our map of consonants last episode, our map of the vowel space is getting a bit cluttered.

Instead of writing these on a picture of the mouth, we can make a drawing that represents the vowel space.

Since our jaw moves like a hinge, we have more space at the front and top of the vowel space than at the back and bottom.

So we represent it by drawing the vowel space as a trapezoid.

This is the vowel space.

We can describe all possible vowels by focusing on the features of closedness, frontness and rounding.

Since it's hard to draw a diagram in three dimensions, we represent rounding by listing the symbols in pairs, where the unrounded one is always first.

Languages vary a lot in how many vowels they have.

Let’s turn the Thought Bubble into a vowel space and step in to look at differences in vowel inventories across languages.

English has a large number of vowels.

Like we said before, the number and type varies a lot between varieties of English.

Most varieties have at least 16 distinct vowel sounds, but some, like Australian English, can have around twenty.

No wonder we need so many symbols in the IPA!

Because vowels exist in an open space, it gives them more freedom to move around than consonants have, which is why vowels often stand out in different accents.

A vowel inventory is the number of distinct vowel sounds in a particular language.

Other languages with large vowel inventories include other Germanic languages, languages across South East Asia, and languages from several families across the equatorial zone of Africa, like Niger-Congo, Nilo-Saharan and Afro-Asiatic.

Many languages have inventories with around 5 or 6 vowels.

This appears to be the middle ground for vowel systems.

One example is Spanish, which has the vowels [i, e, u, o] and [a].

Because this 5-vowel system is so common, the IPA uses the basic Latin vowel symbols for these sounds and reserves the fancier symbols for rarer sounds.

At the other end of the spectrum, there are many languages that get along fine with a much smaller vowel inventory.

This includes Arabic, the majority of Australian languages, and languages of the Caucases.

Languages with smaller vowel sets tend to have much more complex consonant inventories, so things balance out.

Thaaaank youuuuu Thought Bubble!

Different languages can have vowels sit in any part of the vowel space.

Therefore, the symbols on the IPA chart are like anchor points that indicate common distinctions in these features, and more precise distinctions can be indicated by adding diacritics like these.

We’re going to look briefly at three of these distinctions: length, nasalization and tone.

First is length, which is the amount of time a vowel is produced for, like the difference between [i] and [iː].

To indicate length, the IPA adds a diacritic that looks almost like a colon but with tiny triangles instead of dots.

Some languages that use vowel length to distinguish between words are Arabic, Japanese, and Finnish.

You might be able to perceive a length distinction without realizing it.

Think about the Spanish or Italian for ‘yes,’ si, and the English verb ‘to see.’ They use the same vowel, but in English it’s much longer.

Second is nasalization.

We make the vowel sounds we've been talking about so far by moving air through our mouth.

We can also make sounds by letting air flow through the nose.

We make nasal consonants like [m] and [n] by completely blocking the air in the mouth and having it come out the nose, but we can also make nasal vowels with both the mouth and the nose open.

This is known as nasalization, and it has a diacritic too.

Nasalization is a feature of French.

‘Beau’ meaning "beautiful" and ‘bon’ meaning "good" differ in that ‘bon’ has a nasalized vowel.

In English, you might have encountered nasalization in a very relaxed pronunciation of "I dunno" or "uh uh uh.

Finally, we turn to tone.

In many languages, changing the pitch of the voice to make different tones on vowels can create completely different words.

In Mandarin the word mā means ‘mother’, while mǎ means ‘horse’.

Languages can have tone systems with anywhere from 2 to 9 tones, like some Kam–Sui languages of southern China.

Tone systems are common across Asia and Africa, and different languages do different things within the general category of tone.

Some tone systems have a different tone for each syllable for a word, while others have one tone per word.

In other languages, including English, we change the pitch of our voice to change the meaning of a whole sentence.

For example, the pitch rises at the end of a sentence to indicate that something is a question?

and there’s still more to say?

This is known as intonation instead of tone.

And with that, that’s the second part of the IPA!

Now we’re no longer disemvoweled!

In these past two episodes, we’ve been focusing on how people make sounds, which is the branch of phonetics known as articulatory phonetics.

There’s also a branch that makes recordings of these sounds and analyzes them, known as acoustic phonetics, and one that studies how people process the speech that they hear, known as perceptual phonetics.

So far, we’ve described the properties of sounds in isolation.

But when these sounds all run together in speech they can start to affect each other.

In the next episode we’ll look at phonology, and what happens to sounds when we put them in context.

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