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Phonological Theories Phonological Theories

• Most current phonological theories have • Up to the 1950s, the focus had been on arisen out of . analysis of what the speaker produced • linguists are attempting to understand how (surface form). is organized in the brain. • All current theories are based on the • They have not yet succeeded. idea of features as abstract things • No one theory currently is used by all stored in the brain SLPs. • It’s believed that what is in the brain and what is produced may not be the same.

Distinctive Theory Distinctive Feature Theory

• When we describe speech sounds, we • In this theory the basic unit is the use terms like: place, manner, voicing, feature (not the ) height, lip rounding, . • features can't be broken into smaller units. • When we specify one of these • Features are binary; all descriptions, we are defining the either have [+] or don't have [-] a articulatory features of the particular particular feature. sound. • Several feature systems have been proposed.

Distinctive Feature Theory Distinctive Feature Theory

• Features may be based on: • Proponents of this theory believe that • Acoustic properties (e.g., strident, voice). phonemes are stored in the brain as • Articulatory properties (e.g., high, back, “bundles of features”. lateral, coronal). • Like phonemes, features are considered to • Function in a (e.g., consonantal, be abstract mental notions. vocalic). • Features are called “distinctive” because they allow us to distinguish among phonemes.

1 Distinctive Feature Theory Distinctive Feature Theory

• Two phones are different phonemes if • How do we use it clinically? Well... at least one of their features is different. • If features are truly the basic unit, children • / p / = + consonantal, + anterior, - voice will learn features. • / b / = + consonantal, + anterior, + voice • Errors may be based on unlearned features rather than unlearned sounds.

Distinctive Feature Theory Distinctive Feature Theory

• This theory could potentially help us clinically. • Consider the following minimal pairs: • If we look at features rather than phonemes • pin – bin; pin – sin; pin – gin errors that look unique at the phoneme level • Are these minimal pairs equivalent? may actually have a common basis. • What looks like several errors may actually be a • Differ on varying numbers of features: common problem of not having learned a single • pin – bin (1; voicing). feature. • pin – sin (2; place, manner). • E.g., child’s errors may all be on [+] strident sounds or on [+] sounds. • pin – gin (3; place, manner & voicing).

Distinctive Feature Theory Generative Grammar

• Such pairs are equivalent for most • This theory says that when we have an current clinical approaches. idea to express, we choose the • But if children really are learning morphemes we need. features perhaps they should NOT be • Then we assemble the words into considered equivalent. utterances using the rules of the • The “maximal oppositions” approach grammar. assumes they are not (more later). • This “plan” then goes to the speech motor system and is expressed physically.

2 Generative Grammar Generative

• Each element in the lexicon is stored • One part of the underlying with details about what features are representation relates to the phonemes. needed to assemble the necessary • The details of how the phonemes are phonemes. stored in the brain are often specifically • This is the “underlying representation”. referred to as the “phonological • The rules specify how phonemes, representation”. morphemes, words, and utterances must be combined to express the idea in a grammatically correct way.

Generative Phonology Generative Phonology

• What is produced by the speech organs • The theory says that phonological rules is called the “surface form” or “phonetic make use of distinctive features. representation”. • Sounds that share features form • A subset of the grammatical rules are “natural sound classes”. the “phonological rules” which describe • Natural sound classes are often subject how we get from the phonological to the same kinds of changes. representation to the phonetic representation.

Generative Phonology Generative Phonology

• The phonological rules include: • An example of a : • Allophonic rules • Final voiced tend to be • Morpheme structure rules devoiced at the ends of words (an • Sequential constraints allophonic rule) • Morphophonemic rules [+ cons., +voice] Æ [+cons., -voice] / _#

3 Generative Phonology Generative Phonology

• If we want to apply this theory clinically we • Example of a child’s rule: can examine a child’s productions. • Attempts the word “soon” and “kiss” but • Look for changes that occur and the contexts in which they occur. produces [tun] and [kɪt] respectively. • The child may have their own set of rules. • /t/ substituted for /s/ . • What looks like a series of independent errors • /t/ differs from /s/ on the feature continuant. may be the result of a common rule. • The child substitutes the feature [-] • If we can discover the child's rules we can continuant for [+] continuant. try to change them and it should change all the errors affected by the old rules.

Generative Phonology Naturalness and

• If the child’s only error like this is using • Features or sounds that are more /t/ in place of /s/ , there is no advantage common in the world’s are to talking about a “feature substitution considered more “natural”. rule”. • As languages develop, certain sounds • If however, the child also says: may be selected for use because they Æ Æ Æ . • fæn pæn, væn bæn, zu du are easier to learn. • A pattern emerges and we can describe the error pattern using a rule. • May be because they may be easier to produce and/or easier to hear.

Naturalness and Markedness Generative Markedness

• If sounds truly are more natural, many • Generative phonology also says we can languages will select them for use. predict normal development. • Features or sounds that are more natural are • Marked sounds are less common in the said to be "unmarked" because we assume they are the ones children learn first. languages of the world which may mean they are more difficult to learn (less • "Marked" features or sounds are those that are less common in the world’s languages. natural). • they may be harder to learn. • Children should learn unmarked sounds first.

4 Generative Phonology Generative Phonology

Markedness says that: Markedness predictions (cont.) • Voiceless are more natural • Low-front are the most natural than voiced obstruents. vowels. • Obstruents are more natural than • Tense vowels are more natural than lax . vowels. • Stops are more natural than fricatives. • Anterior consonants are more natural • Fricatives are more natural than than non-anterior consonants. .

Generative Phonology Natural Phonology

• How do we use it clinically? • Natural phonology suggests that in their • It highlights the difference that may exist desire to communicate, children simplify between a child’s underlying what they want to say to make it representation and surface form possible for them to produce it. • We look for phonological rules that account • This theory assumes that young for error patterns children's "underlying representations" • We distinguish between natural and are just like an adult's. unnatural error patterns

Natural Phonology Natural Phonology

• As their abilities improve, they slowly • Phonological development = learning to reduce the amount of simplification. suppress (stop using) the natural • Eventually their speech comes to sound processes. like that of an adult. • Phonological disorders = delay or • Simplifications = “natural processes” inability to suppress the processes. • Believed to be innate, universal, mental operations. • Sometimes just called phonological processes.

5 Natural Processes Natural Processes

• Many different lists of processes have Several broad categories of processes been proposed (no one agreed upon). • Syllable structure processes (change • Several published tests available. the number or shape of in • Each test author has chosen a particular the word), e.g. set of processes that they feel are either • Weak syllable deletion the most common or the most important. • Final deletion

Natural Processes Natural Processes

• Substitution processes (one sound • Assimilatory (harmony) processes class is replaced by another), e.g. (sounds change so they are like another • Stopping: substitution of a stop for a sound in the word), e.g. continuant sound e.g., /sʌn/ Æ /tʌn/. • velar assimilation • Fronting: substitution of a front sound for a • labial assimilation back sound e.g., /wit/ for /wik/ .

Natural Phonology Natural Phonology

• Like Generative Phonology’s “rules”, the • Widely used by SLPs processes presented by Natural • Especially helpful with highly Phonology are only descriptions of what unintelligible children who produce is being observed. many errors. • Like generative phonology it allows us to • We have no way of knowing if these reduce many errors into a more actually represent what is happening in manageable number of “patterns”. the brain. • In principle, if we treat the pattern all affected sounds will improve.

6 Natural Phonology Natural Phonology

Children with phonological disorders may: • A significant problem with this theory is • Retain early ‘typical’ processes. that errors can sometimes be described • Demonstrate systematic sound with more than one process: preferences. • E.g., /fɪks/ Æ /fik/ could be "cluster reduction" or "stridency deletion". • Use unusual processes. • We try to resolve this by determining • Exhibit variable process use. which process is more frequent

Nonlinear Nonlinear Phonologies

• A broad group of theories. • Generative and Natural Phonology • Developed since the 1970s but only assume that speech is assembled in the recently being considered in SLP brain and produced in a sequential research and practice. (linear) fashion. • Only focused on the individual speech sounds or their features. • Assume that all features and sounds are equal.

Nonlinear Phonology Nonlinear Phonologies

• Later researchers recognized that • The idea of tiers or levels was not new features may also be arranged in a (only its application to phonology). hierarchy (a series of levels or “tiers”). • It is very similar to the organization • Really just an extension of the idea that often proposed for the syntax of phonemes consist of features (from language. Generative Phonology).

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