So today we'll be talking more about articulatory phonetics,

which again is the study of the production of speech sounds in the vocal tract.

If you haven't already, please take a few minutes to look at our other videos in this series

on describing consonant sounds and navigating the international phonetic alphabet.

In this video we will be talking about how linguists describe vowel sounds.

Just a couple of notes. First again like in the constant video

we will only be talking about the phonetics of spoken language rather than sign languages

and we will be talking about the vowel sounds as they are used in North American English.

There are two types of vowel sounds:

Monophthongs and Diphthongs.

Monophthongs involve one vowel quality and diphthongs involve too vowel qualities.

When linguists are describing vowel sounds, we have to rely on a different set of criteria

for what we used in describing consonants because

remember, vowels do not involve the constriction of airflow in the vocal tract.

so our tongue doesn't approach an anatomical landmark like they do with consonants

so the three criteria that linguists use when describing vowel sounds are

height, backness and roudedness.

Let's talk about each of these in turn.

Height refers to how high or or low the tongue is in the mouth when producing the vowel.

For example, consider the vowel sounds, [i] and [a].

If you say both of these vowels in succession,

you should feel your tongue going up and down as you say [i], [a], [i], [a], [i], [a].

In terms of height, vowels are either considered high, mid, or low.

[i] is an example of the high vowel.

[ɑ] is an example of the low vowel.

Backness refers to how far front or back the tongue is when producing the vowel.

As with vowel height, this can be tricky as it takes some practice,

but consider the vowels, [i] and [u].

If you say these vowels in succession, you may notice that your tongue is

moving forward and backward as you say [i] [u] [i] [u] [i] [u].

In terms of backness, vowels are either considered front, central or back.

Remember that [i] is a high vowel but it's also a front vowel.

while [u] is a back vowel.

The third criteria that linguists use when describing vowels is roundedness.

Roundedness means whether or not the lips are rounded when producing the vowel.

This is something that's very easy as you can feel and see when you are producing a rounded sound,

or when the person that you're talking to is producing a rounded sound.

so again take the two sounds that we just used.

[i] and [u].

[u] as you can clearly see and feel is a rounded vowel whereas [i] is not a rounded vowel.

[i] [u] [i] [u] [i] [u]

Just like with consonants there is a specific order that linguist use when describing vowel sounds.

It is height, then backness, then roundedness.

For example, [u] is a high back rounded vowel.

[Ê] is a low front urounded vowel.

Remember, so far we've only been talking about monophthong vowels.

If you want to categorize diphthongs in terms of these criteria

we must do so for by starting vowel quality as well as the ending vowel quality.

But we won't worry about that in this video.

Alright so what do we cover in this video?

We talked about the criteria that linguist use when describing vowel sounds,

and the order that those criteria must appear in,

and that's pretty much it for this video.

Be sure to check out our other videos and describing consonant sounds

and how to navigate the international phonetic alphabet.

I hope you enjoy this video. Thanks for watching.