phonological processes

What are Phonological Processes?

Phonological processes are patterns of sound errors that typically developing children use to simplify speech as they are learning to talk. They do this because they don’t have the ability to coordinate the lips, tongue, teeth, palate and jaw for clear speech. As a result they simplify complex words in predictable ways until they develop the coordination required to articulate clearly. For example, they may reduce consonant clusters to a single consonant like, “pane” for “plane” or delete the weak syllable in a word saying, “nana” for “banana.” There are many different patterns of simplifications or phonological processes.

Below I’ve included a link to download my Phonological Processes Chart which lists common phonological processes and an approximate age at which children should no longer be using them.

What is a phonological disorder?

These processes are considered normal unless they persist beyond the age when most typically developing children have stopped using them. For example if your 4 year old still uses the phonological process of “reduplication” (saying, “wawa” for “water”) that would be considered delayed since most children stop using that process by the time they turn 3.

A phonological delay may also be considered if the processes the child is using are different than what would be expected. For example, if your child leaves all of the beginning sounds off of his/her words it would be considered a delay since “initial consonant deletion” is not common in typical development.

The excessive use of phonological processes can also indicate a phonological disorder because when multiple phonological processes are exhibited together it usually increases the child’s unintelligibility making them really difficult to understand. As a result, if you have a highly unintelligible child they’re likely to have a phonological delay, and their phonological skills should be assessed when considering a treatment plan.

If you’re uncertain as to how intelligible your child should be based on their age, the standard guideline is by 2 years old a child should be 50% intelligible to an unfamiliar listener. By 3 years old they should be 75% intelligible to an unfamiliar listener and by 4-5 years old they should be close to 100% intelligible to an unfamiliar listener even if a few articulation errors are still present in their speech.

COMMUNICATION THEORY

Communication theory    is a field of information and mathematics that studies the technical process of information and the human process of human communication. According to communication theorist Robert T. Craig in his essay 'Communication Theory as a Field' (1999), "despite the ancient roots and growing profusion of theories about communication," there is not a field of study that can be identified as 'communication theory'.

Origins

The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point. Claude Shannon (1916-2001)

The origins of communication theory is linked to the development of information theory in the early 1920s. Limited information-theoretic ideas had been developed at Bell Labs, all implicitly assuming events of equal probability.

Harry Nyquist's 1924 paper, Certain Factors Affecting Telegraph Speed, contains a theoretical section quantifying "intelligence" and the "line speed" at which it can be transmitted by a communication system.

Ralph Hartley's 1928 paper, Transmission of Information, uses the word information as a measurable quantity, reflecting the receiver's ability to distinguish one sequence of symbols from any other. The natural unit of information was therefore the decimal digit, much later renamed the hartley in his honour as a unit or scale or measure of information.

Alan Turing in 1940 used similar ideas as part of the statistical analysis of the breaking of the German second world war Enigma ciphers.

The main landmark event that opened the way to the development of communication theory was the publication of an article by Claude Shannon in the Bell System Technical Journal in July and October 1948 under the title 'A Mathematical Theory of Communication.' Shannon focused on the problem of how best to encode the information that a sender wants to transmit. He used also tools in probability theory, developed by Norbert Wiener. They marked the nascent stages of applied communication theory at that time. Shannon developed information entropy as a measure for the uncertainty in a message while essentially inventing the field of information theory.

In 1949, a declassified version of his wartime work on the mathematical theory of cryptography ('Communication Theory of Secrecy Systems',) he proved that all theoretically unbreakable ciphers must have the same requirements as the one-time pad. He is also credited with the introduction of sampling theory, which is concerned with representing a continuous-time signal from a (uniform) discrete set of samples. This theory was essential in enabling telecommunications to move from analog to digital transmissions systems in the 1960s and later.

In 1951, Shannon made his fundamental contribution to natural language processing and computational linguistics with his article 'Prediction and Entropy of Printed English' (1951), providing a clear quantifiable link between cultural practice and probabilistic cognition.

MI EXPOSICION

Participants:  Danny Sicat: 13.872.572

                        Yennifer Sanchez 18.912.208

The English Consonants

Have you ever noticed how the 'c' in 'cat' and 'k' in kite' are pronounced the same way, but spelled differently? Or how the 'ch' in 'cheese' and the one in 'cache' is pronounced differently although they're spelled the same? That's because those letters represent different consonants!

There are 24 consonants in the English language, and each consonant represents different sounds. No, I'm not talking about alphabets (your ABCs), but the sounds of the English language. Out of the 24 consonants, 17 are represented by the English Alphabet.

Look at the table below to find out what are the consonants in English:

	Voicing	Place of Articulation
	vl v	Bilabial	Labiodental	Dental	Alveolar	Palato-Alveolar (Post Alveolar)	Palatal	Velar	Glottal
Manner of Articulation	Plosive	p b			t d			k g	ʔ
	Fricative		f v	θ ð	s z	ʃ ʒ		ŋ	h
	Affricate					tʃ dʒ
	Nasal	m			n
	Lateral				l
	Approximant	w				r	j

The table above shows all 24 consonants of the English language. Including the glottal stop /ʔ/, there are 25. Glottal stops are common among Londoners - Cockney speakers in particular - and a few other communities who speak English.

The weird symbols you see are IPA symbols, which are the official symbols used to represent sounds. The sounds of English are represented by IPA symbols enclosed in slashes //. These are called phonemes. IPA symbols enclosed in brackets [] are called phones. The easiest way to understand the difference between the phonemes and phones is that phonemes distinguishes the meaning of two words that are almost identical save for one consonant or vowel or diphthong. For example, 'tin' and 'din' have different meanings because the first phoneme of both words are different. 'Tin' starts with /t/ while 'din' starts with /d/.

Phones do not distinguish the meaning of words because they merely represent the different ways of pronouncing a phoneme. In other words, if you substitute one phone with the another, the meaning of the word will not change. For example, /t/ may be pronounced as [t] or with and aspiration (a puff of air) accompanying the /t/ sound. This aspirated version of [t] would then be symbolised as [th]. Then there's the American pronunciation of /t/ in the middle of words like 'water'. The [t] in 'water' would then be symbolised as [D]. So you would conclude that the phoneme /t/ can be pronounced as [t], [th], [D]. Pronouncing water with a [D] (called a 'flap') will not change the meaning, but pronouncing it with a /d/ will.


Manner and Place of Articulation

Notice the heading labelled 'Manner of Articulation', 'Place of Articulation' and 'Voicing' in the table above. Now, what could all those fancy terms mean?

'Manner of Articulation' simply means the way that the consonants are produced. So a simple version of that heading would be 'Ways of Production'. There are six ways to produce consonants, which are plosive, fricative, affricate, nasal, lateral, andapproximant. All these will be explained in the next section.

'Place of Articulation' actually means the place where the consonants are produced. You could say that the simpler version would be 'Place of Production'. As you can see from the table, there are eight places where consonants are produced and those arebilabial, labiodental, dental, alveolar, palato-alveolar (or post-alveolar), palatal, velar, and glottal. In the next section, we will explore what all these means.

Next is 'Voicing'. Voicing actually refers to the vibration that occurs in our vocal tract when we produce a consonant. Certain consonants causes vibrations when they are produced while other don't. Consonants that cause vibrations when produced are called voiced consonants which are abbreviated as v in the table, while consonants that don't cause vibrations when produced are called voiceless consonants which are abbreviated as vl in the table. So looking at the table, you would know that the consonant /p/ is voiceless because it is on the left corner, just as the vl symbol, while the consonant /b/ is voiced because it is on the right corner, just as the v symbol.

Before we move on to the explanation for each manner and place of articulation, let's first look at the articulators, or the organs, involved in producing the sounds of English - the consonants, vowels and diphthongs (we will look at vowels and diphthongs later on).

As you can see from the diagram above, the mouth isn't just the mouth and the throat isn't just the throat. There are many organs with specific names and functions within our mouth and throat that are vital to the production of sounds. All the parts labelled in the diagram are used in the production of English vowels, consonants and diphthongs - except the uvula, oesophagus and the epiglottis. However, please note that there are labels missing from the diagram, which you will be able to add yourself once you're familiar with all the speech organs.

Imagine someone missing his two front teeth - he would sound very funny if he tried to speak! That's because teeth, as are the lips, are important to the production of sound. Contrary to popular belief, the teeth - namely the upper front teeth - is important in speech, especially in the production of labiodental and dental fricatives. Without the upper front teeth, it would be impossible to say 'van' or 'fan' or 'think' or 'that'.

Apart from sensing salty, bitter, sweet and sour tastes, the tongue is also responsible for articulating consonants, vowels and diphthongs. It is divided into six parts - the tip, blade, front, centre, back, and root. You can observe the position of the tip, blade, front and back of the tongue from the diagram. The centre of the tongue is situated in between the front and back of the tongue while the root is situated after the back of the tongue and is opposite the wall of the pharynx. It's not possible to see the tongue root as it is too far down the throat. The whole tongue, from the tip to the root, is known as the tongue body.

The roof of the mouth is also divided into several sections - alveolar ridge, hard palate, soft palate and uvula. These are all clearly indicated in the diagram. The hard palate is often referred to merely as the palate, while the soft palate is often referred to as the velum. The velum can be lowered to block the passage of air into the oral cavity or raised to block the passage of air into the nasal cavity. It is the only part of the roof of the mouth that can be moved.

The larynx, which is also known as the voice box, holds the vocal folds (or vocal cords). The opening between the vocal folds is called the glottis. Below is a diagram of the larynx. It is here that the air is disturbed to produced either voiced or voiceless consonants. When the vocal cords are apart, air can pass without obstruction, producing voiceless consonants; but when thevocal cords are close together, air has to pass through a narrow opening, producing voiced consonants. This phenomenon is called voicing and you can tell whether a consonant is voiced or voiceless by placing two fingers on your throat when you say /p/ and /b/. /b/ is voiced so you'll be able to feel a vibration in your throat when you say it, but you will not feel any vibration when you say /p/ because it is voiceless. Try it yourself so you will understand better what I'm talking about. If you're not sure how /p/ and /b/ sounds, use the English soundboard at the very bottom of this page to help you.

Now that you're familiar with the the organs of speech, let's go back to the topic of manner and place of articulation. Study the table below once again.

	Voicing	Place of Articulation
	vl v	Bilabial	Labiodental	Dental	Alveolar	Palato-Alveolar (Post Alveolar)	Palatal	Velar	Glottal
Manner of Articulation	Plosive	p b			t d			k g	ʔ
	Fricative		f v	θ ð	s z	ʃ ʒ		ŋ	h
	Affricate					tʃ dʒ
	Nasal	m			n
	Lateral				l
	Approximant	w				r	j

As I mentioned before, place refers to the parts of the speech organs where consonants are produced while the manner refers to the way that consonants are produced. Lets take a look at the manner of articulation first, and then move on to the place of articulation.


Manner of Articulation

There are six manner of articulation - plosive, fricatice, affricate, nasal, lateral and approximant. Let's examine each manner at a time.

1. Plosive

A plosive is called thus due to the small explosion of air produced when a plosive consonant is articulated. Try placing your palm in front of your mouth and saying /p/ and /b/ consecutively. You will feel a puff of air against your palm, like a mini explosion. This happens when the air is stopped in mid-flow, causing pressure to build up in the mouth. When this pressurised air is released, it escapes forcefully through the lips in a puff of air. To memorise this manner of articulation better, remember that the word 'plosive' comes from the word 'explosive' and always do the palm test I mentioned earlier - if you feel a puff of air against your palm when you say a consonant, it's a plosive.

2. Fricative

A fricative consonant is produce by obstructing the airstream while it passes through the oral cavity. This obstruction is done using any combination of articulators, whether it's the upper lip and lower teeth, the tongue and teeth, or the alveolar ridge and the tongue blade. Fricative consonants are produced when the articulators are brought so close together that the airflow is severly blocked. This means that air is forced to escape through a very narrow opening, causing turbulence.

I find it easier to remember fricatives by associating it with the word friction - and rightly so! The friction caused by two articulators working together is what produces the sounds /f/, /v/, /s/, /z/, /θ/, /ð/, /ʃ/, /ʒ/ and /h/. But then, you ask, how do I know if there is friction or not? That's easy! Fricatives are characterised by the hissing sound that accompanies the production of such consonants. For instance, try saying /f/ and /v/ - you'll hear the hissing sound I mentioned.

3. Affricate

There are only two affricate consonants in English: /tʃ/ and /dʒ/. And even though fricative has to do with friction, affricate has nothing to do with Africa. What you should remember about affricates is that an affricate is a combination of a plosive and a fricative. Thus, affricated are sounds produced when airflow is blocked completely(as with plosives) and then gradually released(as with fricatives). For instance, /tʃ/ begins with the plosive /t/ and ends with the fricative /ʃ/. Of course the two consonants aren't to be pronounced separately or you would be hearing 'teh-sheh' instead of 'ch'. Try saying 'chair' and listen to the 'ch' sound - that's actually /tʃ/ you're hearing. The same goes for /dʒ/: it's a combination of /d/ and /ʒ/. You can hear the consonant/dʒ/ at the beginning and the end of the word 'judge'.

4. Nasal

If you've ever suffered the flu and had to speak while still sick, you would know what nasal sounds are like. Nasals are sounds produced when air escapes only through the nasal cavity(nose). Air doesn't flow through the oral cavity(mouth) because thevelum is lowered, blocking the opening to the oral cavity. There are only three nasal consonants in the English language: /n/, /m/ and /ŋ/. All three nasal consonants are fairly common in English. In fact, the last three words of the previous sentence contain them:

common - /kɒmən/
in - /ɪn/
English - /ɪŋɡlɪʃ

5. Lateral

While there may be many lateral sounds in other languages, there is only one in the English language - the /l/ sound. Words like 'love, 'life' 'lame', 'leave' and 'lazy' all begin with a lateral consonant. Lateral literally means 'the side of something' so laterals are sounds produced when the air flows through the sides of the tongue. The only obstruction occurs where the tip (or blade) of the tongue touches the alveolar ridge.

6. Approximant

When you say, 'approximately', you mean that something is close to another thing, but not quite there. For example, if you say 'I'll be arriving at approximately 10 am' you mean that you will be arriving at around that time, but not at exactly 10 am. The same goes for approximant consonants. The articulators involved in producing approximant sounds approach each other closely but do not touch. Thus, approximants can be defined as sounds produced when articulators approach each other but not close enough to obstruct airflow. For example, try saying /w/, or the word 'wait'. When your lips move to produce the /w/ sound, your upper lip and lower lip move close together but they don't touch. It's the same with the consonant /j/ as in 'yet' and /r/ as in 'red'.

And now that we're done with manner of articulation, let's move on to place of articulation!


Place of Articulation
There are eight places of articulation involved in the production of all 24 English consonants - bilabial, labiodental, dental, alveolar, post-alveolar, palatal, velar and glottal. Each one refers to a place in the mouth where the different consonants are produced. I'll explain each one to help you understand them.

1. Bilabial

Bilabial is the first checkpoint in the topic of place of articulation. 'Labia' means 'lip' and 'bi' means 'two'. So bilabial actually refers to our two lips. Bilabial consonants are produced by bringing the upper lip and lower lip together, and these consonants include /p/ as in 'pin', /b/ as in 'ball', /w/ as in 'wet', and /m/ as in 'mix'. In all bilabial consonants, the upper lip is considered the passive articulator while the lower lip is the active. This simply means that the upper lip doesn't move (or at least not so much) but the lower lip does. It is the lower lip that approaches the upper lip when bilabials sounds are being made.

2. Labiodental

Labiodentals involve the lip and the teeth - specifically, the lower lip and the upper teeth. Labiodental sounds are produced when the bottom lip (which is the active articulator) is brought up towards the upper teeth (which is the passive articulator). /f/ (as in 'fan') and /v/ (as in 'van') are labiodental sounds.

3. Dental

By now, you would've already known that dental refers to teeth. *In dental sounds, the tongue tip is placed between the upper and lower teeth. In this case, the tongue tip and the lower teeth are the active articulators while the upper teeth is the passve articulators. There are only two dental consonants in English: /θ/ as in 'think', and /ð/ as in 'that'.

In actuality, the specific term for this is interdental. Dental sounds are produced by placing the tongue tip behind the upper front teeth. However for easy learning purposes, we will ignore this and stick to dental. You may distinguish between these two once you have a clear understanding of phonetics.

4. Alveolar

Alveolar sounds are called thus because these sounds are produced at the alveolar ridge, which is a small bump just behind the upper teeth. If you're not sure where that is, refer to the diagram above. Alveolar sounds are produced when the tongue blade (the active articulator) is brought towards the alveolar ridge (the passive articulator). However, some people may produce alveolar consonants by placing the tongue tip against the alveolar ridge, instead of the tongue blade. Both ways are acceptable. Consonants which fall into this category are /t/ as in 'tin', /d/ as in 'den', /n/ as in 'net', /s/ as in 'sun', /z/ as in 'zip' and /l/ as in 'leg'.

5. Post-alveolar

Post-alveolar consonants are produced by placing the tongue blade behind the alveolar ridge, in front of the hard palate. Hence, the word 'post' because the placement of the tongue is behind the alveolar ridge. Post-alveolar consonants include /ʃ/ which is heard in 'shoe, /ʒ/ which is heard in the middle of 'measure', /tʃ/ which is heard in front of 'church', /dʒ/ which is heard in front of 'jungle', and /r/ which is heard in front of 'red'.

6. Palatal

As you might have guessed, palatal sounds are produced when the tongue body is brought towads the hard palate. The active articulator here is the tongue body while the passive articulator is the hard palate. There is only one palatal sound and that is the /j/ sound. No, that's not 'j' as in 'jet' but rather a 'y' as is 'yet'. So the transcription for 'yet' would not be /yet/ but rather /jet/.

7. Velars

Velar sounds are produced with the velum or soft palate playing the central role. A velar sound such a /k/ as in 'kite' is produced when the back of the tongue is raised towards the velum. The back of the tongue takes on the active articulator role, while the velum takes on the passive articulator role. Other consonants that are classified as velar sounds are /g/ as in 'gate' and /ŋ/ as in 'sing'.

8. Glottal

Glottal sounds are made when air flows through the different states of the glottis. The articulators involvd are the vocal cords. In the production of the /h/ consonant, the vocal cords are open but they are close enough together so that air passing between them (through the glottis) creates friction. On the other hand in the production of the /ʔ/ consonant (or the 'glottal stop'), the vocal cords close momentarily, cutting off all airflow through the glottis. As mention in the introduction, glottal stops are common among Cockney speakers. When you 'uh-oh' after something goes wrong, you are also making a glottal stop sound.

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