Hi and welcome to the second module. The module in which we will talk about the sounds of language. This is the first video in that second module. There are actually two subdisciplines of linguistics which study sounds. They're called phonetics and phonology. Phonetics studies the physical and physiological aspects of those sounds the way in which they vibrate in the air, the way I produce them using my articulatory organs. Phonology studies them as part of language. This means that if we study phonology, we can omit a lot of details on how you actually produce a sound, which is not linguistically relevant. As a matter of fact, if I say the same word twice, man, man, I do something slightly different in each case that may be interesting for a phonetician. But not for phonologist, because it's the same word. In this module, we're going to study the sound inventories of language and in order to do that, I'm also going to introduce you to the so-called International Phonetic Alphabet, IPA. Further, we will study the properties of consonants and they will show you how this information can tell us something about speech errors that people make. But now, welcome to the world of sounds. Apart from sign languages, which obviously are produced in a slightly different way, every language is produced by sounds. These sounds furthermore, always have the shape of a finite set, there's a finite inventory of sounds, which a language uses that's roughly something between 20 and 200 different vowels and consonants, differs from one language to the next. Certain sounds are never used in language, even though they are easy to produced. So, [CLAP] I can easily do that, but it is never used in any language. But all languages use these small sets of building blocks to combine them and make them into words. That's actually a property of human language, which is not necessary. All human languages happen to be like that, but they don't have to be. Because there are so many different sounds we could make, you could easily imagine there would be a language in which, I don't know, man would be [CLAP] indeed this. And loves would be [WHISTLE] and woman would be [SOUND] and then the sentence man loves woman is, [SOUND] but there's no language which works like that. All languages work with these small sets of vowels and consonants. How does that work? Let's take English as an example. Here are all the consonants of the English language. You can see a different symbol is used for every individual consonant. Do you recognize those symbols? Well, probably some of them you do. At least, I hope you recognize the F in fine or the zed in zip, because those are also used in the normal English alphabet. But you may not recognize the symbols, which are used for the consonants in thin and then, unless you're Greek or Icelandic, because those symbols are used in those languages. Why is that? Well, English has more consonants and vowels. There is more building blocks than just those 26 different letters. If you want to write down all those sounds, we need more symbols. If you want to write out all sounds used in all languages, we basically need a very big set of symbols. That's what the International Phonetic Alphabet is. It's a way to write down all different sounds. All different consonants and vowels of every individual human language. It's impossible to look at all sounds at the same time. And therefore, in this module, we will concentrate on consonants rather than vowels. It's an important distinction. All languages seem to distinguish consonants from vowels. Most languages have more consonants than vowels. That's a reason to concentrate on them now. It's an important distinction, but it's not always very easy to make. There are some criteria, here are some of them. The first is that in the production of vowels, there is no impediment in the airstream. If I say, a vowel my mouth is just open and the air goes out unimpeded. Another distinction is that in many languages every syllable has at least a vowel, but not necessarily a consonant. Oh is a possible word or syllable of English, but [T] is not. So we can use a vowel to make a syllable, but not just a consonant. That's very common in many different languages. This video has been all about distinctions. We ended with distinguishing vowels and consonants. But before that we've seen that it's also important to distinguish the consonants of an individual language and that the letters of the alphabet, do not usually suffice to do so. So for English we have more consonants then we have letters, and that's why we have a phonetic alphabet, which adds symbols to them. This, we've also distinguished between phonetics and phonology two separate disciplines of linguistics, which both study the sounds of human language. We are going to look a little bit more into phonetics first and phonology later in the course of this module. We're going to start with phonetics. In the next video, I'm going to talk to you about the articulation of consonants in human language. But I'm not going to do that alone, I'm going to have a very special guest to help me with that.