PhonologyThe idea of feature systems that we have been talking about in relation to phonetics also lends itself quite handily to the description of natural classes of sounds.Phonetic natural classes are groups of sounds in a language which share some articulatory or auditory feature.

PhonologyIn order for a group of sounds to be a natural class, it must include all of the sounds that share a particular feature or group of features, and not include sounds that dont.

PhonologyWe have already talked about several natural classes of sounds, such as stops, fricatives, nasals, affricates, etc.To talk fully about phonetic natural classes, however, we need to clarify a few other features.

PhonologySome sound classes are based on articulation or production: For example, both labio-dental and bilabial involve the lips.Therefore, we can group them together under the term labial.

PhonologyIn English, these sounds are [m, b, p, f, v, w] In English, the sound [w] doesnt occur after any of these sounds. We can use the term labial to simplify the description: [w] doesnt occur after labial sounds.

PhonologyOther natural classes are based on sound quality, or auditory properties.One example of a natural class based on auditory properties is Sibilants. Take a look at the pronunciation of the plural suffix in English, which we will label -sThis suffix is pronounced in three different ways, depending on the last sound in the noun to which it is added.

PhonologyIf the noun ends with a voiced sound the phonetic form is [z].If the noun ends in a voiceless sound the phonetic form is [s].However, after such words as rich, bush, kiss, garages, rouge, and maze, (in other words, [s, z, , , t, d,]) the form is [z].

PhonologyThis group of sounds all differ in respect to voicing, place, and manner of articulation. However, they do have an auditory property in common: a high pitched hissing sound. These sounds, therefore, form a natural class called sibilants.

PhonologySo using this natural class, we can state a generalization:+ plural [z] / after a sibilantThis rule states that the sound occurs in a general context, rather than having to specify for each individual context.

PhonologyOther classes include:Obstruents, which are sounds produced with an obstruction of air flow, namely stops, fricatives, affricates. Sonorants, which are consonants produced with a relatively open passage for the air flow, including nasals, approximants and others (or nasals, liquids, glides, and others).

Distinctive FeaturesIn every language, certain sounds are considered to be the same sound, even though they may be phonetically distinct. For example, native speakers consider the [l] in lay to be the same sound as that in play, even though the former is voiced and the latter voiceless.

Distinctive FeaturesLiquids and glides in English are ordinarily voiced, but when they follow a voiceless obstruent in speech, they are pronounced as voiceless consonants.proof [pruf] sleep

quick[kwk]

Distinctive FeaturesNative speakers overlook the fact that the [p] in pat and spat are phonetically different and just consider them both to be /p/.Hindi speakers, however, cant ignore the difference.

Distinctive FeaturesTake the following data, for example:[kl]wicked person [kl]yesterday[kapi]copy [kapi] ample [pl]fruit [pl]moment [bl]strength

Distinctive FeaturesIn general, speakers will attend to phonetic differences between two (or more) sounds only when the choice between the sounds can change the meaning of a word, - that is, can cause a distinction in meaning. Such sounds are said to be distinctive with respect to one another.

Distinctive FeaturesSo, how do we determine when two sounds are distinctive? One way to determine whether two sounds are distinctive is to identify a minimal pair - a pair of words that differ only by a single sound in the same position - and which have different meanings - but which are otherwise identical.

Distinctive FeaturesSome examples from English are:totvs. hottapvs. toptap vs. tabLets take a second to go back and look again at the examples from Hindi.

Distinctive Features[kl]wicked person [kl]yesterday[kapi]copy [kapi] ample [pl]fruit [pl]moment [bl]strength

Distinctive FeaturesWhat must be considered minimal pairs in Hindi?What sounds do Hindi speakers consider distinctive?

Distinctive FeaturesBefore we proceed any further, we need to discuss some definitions:The first definition we need to consider is that of a Phone, which is simply an individual speech sound.The second definition to consider is that of a Phoneme, which is a class of speech sounds which are identified by a speaker as the same sound.

Distinctive FeaturesThe members of these classes are called Allophones. Thus, an allophone is a phone that has been classified as belonging to some class (phoneme).

Distinctive FeaturesIn English, p in pat and spat are allophones of the same phoneme in English.In Hindi, these sounds are allophones of different phonemes.

Distinctive FeaturesSymbols representing phonemes are written with slash marks instead of brackets.So, in English, we would have one phoneme labeled /p/, with allophones labeled [p] and [p]But in Hindi, we would have two separate phonemes, labeled either /p/ or /p/

Distinctive FeaturesBy giving a description like this, linguists are attempting to show that the phonological system of a language has two levels. The more concrete level involves the physical reality of phonetic segments (which is what phonetics looks at).Phonemes are more on the psychological level; they are more abstract.

Distinctive FeaturesAllophones are physical units of linguistic structure. Phonemes are psychological units of linguistic structure.Phonemes are not directly observable; allophones are.

Distinctive FeaturesWriting systems also reflect this reality. In English, we dont make the orthographic distinction between [p] and [p]. In Hindi, they do.In general, alphabetic writing systems tend to be phonemic rather than phonetic.

Distinctive FeaturesTo find out which sounds are thought of by a native speaker as the same sound, and which sounds are distinctive to one another, it is important to look at where these sounds occur in a language. In other words, linguists try to discover what the phonemes of a language are by examining the distribution of that languages phones.

Distinctive FeaturesThe Distribution of a phone is the set of phonetic environments in which it occurs.Two speech sounds in a language will either be in overlapping distribution or complementary distribution with respect to one another.

Distinctive FeaturesOverlapping distribution occurs when the sets of phonetic environments in which the sounds occur are partially or completely identical. For example, consider [p] and [b]:bait[bet]date[det]lobe[lob]load[lod]knobs[nabz]nods[nadz]

Distinctive FeaturesSince the sets of possible phonetic environments overlap, we say that [b] and [d] are in overlapping distribution in English.

Distinctive FeaturesMost sounds that are in overlapping distribution are contrastive with respect to one another, which is another way of saying they are distinctive sounds.Consider [b] and [d] above: they form minimal pairs. Since the difference between [b] and [d] can result in contrastive meaning, we say that [b] and [d] are in contrastive distribution.

Distinctive FeaturesThese two distinctive phones are classified as being allophones of two separate phonemes. Thus, [b] is an allophone of /b/ and [d] is an allophone of /d/.

Distinctive FeaturesSome other phones that are in overlapping distribution are in free variation. As an example:Leap[lip]leap[lip ]Soap[sop]soap [sop ]Troop[trup]troop [trup ]Happy[haepi]*[haep i]

Distinctive FeaturesThese sounds are in overlapping distribution, because they share some of the same environments: they both appear at the end of words. Unlike [b] and [p], however, there are no minimal pairs. In other words, although they contain the same sounds but one, these words do not contrast in meaning.

Distinctive FeaturesThese sounds are interchangeable in word-final position. So we say that they are allophones of the same phoneme.For example, [p] and [p ] are allophones of /p/

Distinctive FeaturesComplementary Distribution is just the opposite of overlapping distribution. To understand this, think of the term complementary. Two complementary parts make up a whole. People in this class, for example, may be divided up into those who wear glasses and those who dont.

Distinctive FeaturesThese two sets of people complement each other. They are mutually exclusive. That is, they are non-overlapping, but together they make up the whole class.

Distinctive FeaturesAs an example, consider the sounds [p] and [p]Spat[spt]pat[pt]Spool[spul]pool[pul]Speak[spik]peek[pik]

Distinctive FeaturesAs you can see, [p] and [p] are not in overlapping distribution. In other words, they do not occur in the same phonetic environment. In fact, they are in complementary distribution.

Distinctive FeaturesFirst: There are no minimal pairs involving the [p] vs. [p.Second: [p] occurs after [s] but not word initially. [p] occurs word initially, but not after [s].Since these sounds appear in different phonetic environments there can be no pair of words composed of identical strings of sounds except for [p] in one and [p] in the other.

Distinctive FeaturesPhones that are in complementary distribution are allophones of a single phoneme. In this case, [p] and [p] are allophones of the phoneme /p/. The appearance of one allophone or the other is predictable when those allophones are in complementary distribution.

Distinctive FeaturesRecall that phonemes and allophones belong to different levels of structure in language. Phonemes are mental entities.Allophones/phones are physical events. So what is the connection between the two levels?The mapping between phonemic and phonetic elements is accomplished using phonological rules.

Phonological RulesA speakers knowledge of phonological rules allows him or her to translate phonemes into actual sounds.Knowledge of these rules forms part of a speakers linguistic competence.

Phonological RulesThe following is a representation of the process:

Phonemic formrulesphonetic form

Phonological RulesIn other words, phonological rules apply to the phonemic form to produce the phonetic form. To accept this is to accept the notion that there is something called an underlying form. In the linguistic literature, this underlying form is called the Underlying Representation or UR.

Phonological RulesThere are several different ways that we can classify phonological rules.One of the most common types of phonological rules is called Assimilation. Rules involving assimilation cause a sound to become more like a neighboring sound with respect to some feature.

Phonological RulesIn other words, the segment affected by the rule assimilates or takes on a feature from a nearby (usually adjacent) sound. For example:.I can ask[ay kn sk]I can bake[ay km bek]I can go[ay k go]

Phonological RulesAnother type of assimilation is dental assimilation, as in the following examples: width[wd]health[hl]unthinkable[nkbl]in this[ns]

Phonological RulesAnother example is vowel nasalization: pit[pt]pin[pn]

Phonological RulesOther phonological rules involve dissimilation. Rules involving dissimilation cause two neighboring sounds to become less alike with respect to some feature. Dissimilation rules are less common than assimilation rules, at least in English.

Phonological RulesOne example of a dissimilation rule is fricative dissimilation: // changes to [t] following another fricative:fifthphonemically [ff]phonetically often realized as [fft]sixthphonemically [sks]but often realized as [skst]

Phonological RulesAnother classification is insertion (also called epenthesis).Rules of insertion cause a segment not present at the phonemic level to be added to the phonetic realization of a word.

Phonological RulesOne example of an insertion rule is voiceless stop insertion. Between a nasal and a voiceless fricative, a voiceless stop with the same place of articulation as the nasal is inserted. strength /str/ [strk]hampster/hmster/[hmpster]

Phonological RulesAnother classification is Deletion. Deletion rules eliminate a sound. Such rules apply more frequently to unstressed syllables and in casual speech. /h/ - deletion: /h/ may be deleted in unstressed syllables. In the sentence, He handed her his hat, the UR is:/hi hndd hz ht/

Phonological Rulesbut is often represented on the surface as:[hi hndd r ht]

Phonological RulesThe final type of rule that we will concern ourselves with is called metathesisThese rules change the order of sounds

Phonological RulesFor example, for many children, the word that is normally pronounced [spgi] ([spki])gets pronounced as[psgi] ([pski])How about animal?

Phonological RulesThe Format for representing Phonological RulesThe basic format for specifying phonological rules is as follows: A B/ C __ DThis format is meant to be read as A becomes B in the environment following C and preceding D.

Phonological RulesFor example, here are the formulations for two of the rules we have discussed so far: Vowel + nasal/ ___ nasalAlveolar + dental/ ____ dental