What is Phonetics?

Phonetics is the study of the articulatory and acoustic properties of the sounds of human language.

Lessons:

The Physics and Physiology of Speech

Vowels

Consonants: Voicing and Place of Articulation

Acoustics

Consonants: Manner of Articulation

Formants

Extracting Formant Values

The Physics and Physiology of Speech

Introduction

In this lesson, you will be introduced to the major anatomical components of the speech system for human language.

Major Terms

  • trachea

  • larynx

  • glottis

  • pharynx

  • vocal tract
     

Subglottal System

Sound in human language is produced by the regulation of airflow from the lungs through the throat, nose, and mouth. This airflow is altered in various ways by different aspects of this speech system. The first major segment of the speech system is the subglottal system. This subglottal system comprises the lungs, diaphragm and trachea.

The lungs are basically a pair of balloon-like sacs that inflate or deflate by the action of the diaphragm, a muscle just under the lungs, attached to them. When the diaphragm is lowered, the lungs inflate, and when the diaphragm is raised, air is pressed out of the lungs, allowing them to deflate.

When this air is pressed out of the lungs, air travels up the trachea, or windpipe, to the larynx, the next major segment of the speech system.

The Larynx

The larynx is a mass of cartilage at the top of the trachea. It is commonly called the voicebox.

 

The larynx contains folds of muscle called the vocal folds (sometimes called vocal cords). These vocal folds are connected to the larynx by the arytenoid cartilage at the front, but the other ends are left free. The opening between the vocal folds is known as the glottis. These folds can be relaxed, letting air flow freely through the glottis, or tensed, so that the air vibrates as it passes through the glottis.

Sounds that are produced with relaxed vocal folds are known as voiceless sounds, and sounds that are produced with tensed vocal folds are known as voiced sounds. If the folds are only partially closed, a whispered sound is produced.

Vocal and Larynx
Play Video

Above the Larynx

The area above the larynx consists of three main areas: the pharynx, the nasal cavity, and the oral cavity. The pharynx consists of the area above the larynx and below the uvula. The oral cavity is the area from the back of the throat to the mouth. The major parts of the oral cavity that are used in speech production are the uvula, the velum, the tongue, the hard palate, the alveolar ridge, the teeth, and the lips. The uvula is that fleshy blob that hangs down in the back of the throat. The velum is the soft palate, and the alveolar ridge is a mass of hard cartilage behind the teeth.

The following graphic shows these major parts of the area, which is also known as the supraglottal system

Summary

In summary, this lesson has outlined the major parts of the anatomy that relate to speech production. These parts are the following:

  • Subglottal system, including lungs and trachea

  • Larynx, including the vocal folds and glottis

  • Supraglottal system, including the oral cavity, nasal cavity, and pharynx

In the next lesson, you will learn how consonants are classified in terms of the use of these parts of the speech system.

Soft palate.png
Hard Palate.png

Consonants:
Voicing and Place of Articulation

Introduction

In this lesson, the goals are to begin to learn how speech sounds are classified in terms of their use of the speech system.

Major Terms

  • voicing

  • place of articulation

    • bilabial

    • labiodental

    • interdental

    • dental

    • alveolar

    • alveopalatal

    • palatal

    • velar

    • uvular

    • pharyngeal

    • glottal

       

Voicing

In the last lesson, you were introduced to the following states of the glottis: voiceless and voiced. These states are determined by the action of the vocal folds in the larynx. If the vocal folds are held apart, the glottis is in a voiceless state, while if the vocal folds are held together, and allowed to vibrate, the glottis is in a voiced state.

Certain consonants in human language are distinguished by which state is active during production of the sound. For example, pronounce the sound [m], as in mat, and hold the sound. While producing this sound, place your fingers at the base of your throat. You should feel the vibration of the vocal folds. Since the sound [m] is vibrating, this is a voiced sound.

Now make the sound [p], as in pat. You can't really hold this sound, but again put your fingers near the base of your throat while you say [p]. You shouldn't feel much vibration, if any. This is because the vocal folds are held apart, making a voiceless sound.

Now say the sounds [p] and [b], as in bat, with your fingers at the base of the throat. When you say [p], there should be no vibration, but when you say [b], there should be vibration. Think about what you are doing with your mouth to make both sounds. Both sounds are made in basically the same way, but one is voiceless and one is voiced.

Speech and the Vocal Tract

As described in the earlier lesson, speech sound is created by airflow through the vocal tract. In pulmonic sounds, which are the sounds we will consider here, the lungs push air up into the trachea, through the larynx, and outward through the vocal tract.

So how are different sounds made? In part 1, we discussed that one way to make different sounds is to vary the state of the glottis, making either a voiced or voiceless sound.

Another way is to vary the shape of the vocal tract. Imagine the vocal tract as a tube, through which air passes. If this tube is simply open, the airflow creates a sound. But if you alter the shape of that tube, the airflow moves differently, making a different sound.

Here's an experiment that some of you may have tried. Take an empty bottle and blow air across the top of the bottle. If you can get the airflow just right, you should be able to produce a low sound. Now fill the bottle halfway with water. Blow across the bottle opening again. This time the sound is higher. If you put some more water in the bottle, the sound will get even higher.

What's happening? For a more detailed discussion, you can view the lesson Acoustic Phonetics. However, for now, just understand that if the bottle (vocal tract) is not as filled with water (larger), the sound will be a deep, low sound. If the bottle (vocal tract) is filled with water (smaller), the sound will be a higher sound.

When we make speech sounds, one thing that is happening is that we are varying the shape of the vocal tract, making the sound different. For example, say the sound [t]. To make this sound, you are raising the tip of your tongue behind your teeth and then lowering your tongue. When you do this, the air builds up behind the closure made by your tongue and teeth and is then released. When the air is released by the tongue, the air travels outward through a small area, just from the teeth to outside the mouth.

Now say the sound [k]. To make this sound, you are bringing your tongue up to the velum, closing off the airflow, and then lowering your tongue to release the air. This time, when the air is released, it travels through a larger area before leaving the mouth. This space is from the velum to the lips. Thus, the sound made by the airflow is different from that made by [p].

The following diagrams illustrate the amount of space in the vocal tract available for [t] and [k]:

 

As the diagram show, there is more space in the vocal tract for the release of air in the production of [k] than for [t]. Therefore, two distinct sounds are produced.

The point at which the vocal tract is altered is known as the place of articulation. In the next section, we will discuss the major places of articulation in classifying human speech sounds.

Place of Articulation

The term place of articulation, as discussed in the last section, classifies speech sounds in terms of where in the vocal tract the shape of the vocal tract is altered. In this section, we will present the major places of articulation.

Bilabial

Bilabial sounds are those sounds made by the articulation of the lips against each other. Examples of such sounds in English are the following: [b], [p], [m].

Labiodental

Labiodental sounds are those sounds made by the articulation of the upper teeth towards the lower lip. Examples of such sounds in English are the following: [f], [v].

Interdental

Interdental sounds are those sounds made by the articulation of the tongue between the teeth. Examples of such sounds in English are the following: [θ], [ð].

Dental

Dental sounds are those sounds made by the articulation of the tip of the tongue towards the back of the teeth. Such sounds are not present in Standard American English, but in some Chicano English dialects and certain Brooklyn dialects, the sounds [t] and [d] are pronounced with a dental articulation.

Alveolar

Alveolar sounds are those sounds made by the articulation of the tip of the tongue towards the alveolar ridge, the ridge of cartilage behind the teeth. Examples of such sounds in English are the following: [t], [d], [s], [z], [n], [l], [ɾ].

Alveopalatal

Alveopalatal sounds are those sounds made by the articulation of the front of the tongue towards the area between the alveolar ridge and the hard palate. Examples of such sounds in English are the following: [ʃ], [ʒ], [t̠ʃ], [d̠ʒ].

Palatal

Palatal sounds are those sounds made by the articulation of the body of the tongue towards the hard palate. An example of such a sound in English is [j].

Velar

Velar sounds are those sounds made by the articulation of the body of the tongue towards the velum. Examples of such sounds in English are the following: [k], [g], [ŋ].

Uvular

Uvular sounds are those sounds made by the articulation of the back of the tongue towards the uvula. Uvular sounds do not exist in English, but the French "r" is pronounced by the uvular sounds  [χand [ʁ].

Pharyngeal

Pharyngeal sounds are those sounds made by the articulation of the tongue root towards the back of the pharynx. Pharyngeal sounds do not exist in Standard American English, but are found in languages such as Arabic and Hebrew.

Glottal

Glottal sounds are those sounds made at the glottis. Examples of glottal sounds in English are the following: [ʔ], [h].

On the next page is a diagram that illustrates all the places of articulation.

Place of Articulation

This diagram illustrates positions of the articulators in the articulation of certain consonants. 

In the next lesson, you will learn how consonants are classified on the basis of the manner in which the articulators modulate the airflow.

Consonants:
Manner of Articulation

Introduction

In this lesson, the goals are to continue learning how speech sounds are classified in terms of their use of the speech system.

Major Terms

  • manner of articulation

    • plosive

    • fricative

    • affricate

    • nasal

    • approximant

    • glide
       

Manner of Articulation

In the last lesson, you were introduced to the places of articulation. These are the points in the vocal tract at which the articulators alter the shape of the vocal tract to produce distinct consonant sounds.

However, consonants are further distinguished on the basis of how the articulators alter the shape of the vocal tract. That is, how is the airflow regulated by the tongue or lips.

In the following sections, you will be introduced to the major manners of articulation for pulmonic consonants.

Plosives ( /p/ /b/ /d/ /t/ /k/ /g/)

A plosive is formed by the complete obstruction of the vocal tract by the articulators. This obstruction is then released, allowing the air to "explode" out of the mouth.

When the air is blocked by the articulator, it begins to raise in pressure. Then, when the air is released, the high pressure air rushes out into the lower pressure area beyond the blockage. This results in a burst of air, signifiying a plosive. In the following diagram, the dots represent the pressure of the air. The higher pressure area have more dots per area, while the lower pressure areas have fewer dots per area.

Fricatives (/f/ /v/ /s/ /z/ /∫/ /ʒ/ /θ/ /ð/ /h/)

A fricative is formed by a constriction in the vocal tract by the articulators, such as the tongue or the lips. However, unlike stops, the occlusion (blockage) in the vocal tract is not complete. Some of the air is allowed to come through a very narrow opening. This air becomes turbulent, because of the friction between the airflow and the narrow passage.

Fricatives happen in two ways. One way is simply for the air to flow through a narrow opening, like in the sound [f]. Another ways is for the air to be sped up through a narrow passage and then forced across another area, like the teeth, which is the way the sound  is formed. In the following diagram, the dots represent moving air particles. The air behind the occlusion is relatively slow, but the air that is forced between the tongue and the roof of the mouth is much faster and more turbulent.

Affricates (/ʤ/ /ʧ /)

An affricate combines the manners of articulation for the plosive and the fricative. Like a stop, the articulation of the affricate begins with a complete closure of the vocal tract by an articulator. However, when the closure is released, the release is somewhat gradual, providing a narrow space between the articulator and the mouth for the airflow to move through. This narrow space creates an environment similar to a fricative, in that the airflow moving out becomes turbulent for a brief period until full release of the closure.

Nasals (/m/ /n/ /η/)

A nasal is formed by the obstruction of the vocal tract and the lowering of the velum. This lowering of the velum alows the airflow to flow out through the nasal cavity, rather than through the oral cavity.

Approximant (/w/ /j/ /r/ /l/)

An approximant is formed by the constriction of the vocal tract, but with no obstruction in the vocal tract. Therefore, no turbulent airflow, as in a fricative. Instead, the air is allowed to flow freely through the vocal tract.

The sound  is also known as a lateral approximant, since the articulators do touch at a central point, but the air is allowed to flow through one or both sides of the contact point.

Other Articulations

There are two other articulations in varieties of English that should be noted here: the tap and the trill.

A tap is formed by a quick contact between an articulator and the vocal tract. In Standard American English, for example, there is the tap , which can be found in the middle of words such as ladder, and butter.

A trill is formed by the rapid vibration of the tongue tip against the roof of the mouth. This vibration is caused by the motion of a current of air. This sound, represented by , is found, for example, in varieties of British and Scots English. It is also known as a "rolled r".

Summary

In this lesson, you have been introduced to several manners of articulation. These are listed below:

  • Plosive

    • Formed by a blockage of the vocal tract, followed by an explosive release of air

  • Fricative

    • Formed by slight contact between articulators, allowing turbulent airflow

  • Affricate

    • Formed by a blockage of the vocal tract, like plosive, followed by a gradual release of turbulent air, like a fricative

  • Nasal

    • Formed by the lowering of the velum, allowing air to flow through the nasal cavity

  • Approximant

    • Formed by the constriction of the vocal tract, but with no blockage of the airflow

  • Tap

    • Formed by a quick contact between articulators

  • Trill

    • Formed by the rapid vibration of the tongue tip by a current of air

Vowels

Introduction

In this lesson, the goals are discuss how vowel sounds are classified in terms of their use of the speech system.

Major Terms

  • tongue height

  • tongue backness

  • lip rounding

  • tense

  • lax
     

Vowel Classification

In the last two lessons, you were introduced to the classification of consonant sounds. The classification of consonants were shown to be based on three aspects of articulation: place of articulation, manner of articulation, and voicing.

In this lesson, you will be introduced to the classification of vowel sounds. The classifcation of vowels is based on four major aspects: tongue height, tongue backness, lip rounding, and the tenseness of the articulators.

Tongue Height

The first aspect of vowel classification that you will be introduced to is that of tongue height. Vowels are classified in terms of how much space there is between the tongue and the roof of the mouth, which is determined by the height of the tongue.

There are three primary height distinctions among vowels: high, low, and mid.

In English, examples of high vowels are [i], [ɪ], [u], [ʊ]. These are vowels with a relatively narrow space between the tongue and the roof of the mouth. Examples of low vowels are [æ], [a] . These are vowels with a relatively wide space between the tongue and the roof of the mouth. Examples of mid vowels are [e], [ɛ], [o], [ɔ] . These are vowels whose tongue positions are roughly between the high and low vowels.

These classifications are quite relative, as different languages have different canonical tongue heights for different classifications.

Tongue Backness

The second aspect of vowel classification that you will be introduced to is that of tongue backness. Vowels are classified in terms of how far the raised body of the tongue is from the back of the mouth, which is called the backness of the tongue.

There are three primary height distinctions among vowels: front, back, and central.

In English, examples of front vowels are [i], [ɪ], [e], [ɛ], [æ]. These vowels are articulated relatively forward in the mouth. Examples of back vowels are [u], [ʊ], [o], [ɔ]. These vowels are articulated relatively far back in the mouth.. Examples of central vowels are [a], [ə]. These are vowels whose tongue positions are roughly between the front and back vowels.

These classifications, like the tongue heights, are quite relative, as different languages have different canonical tongue backnesses for different classifications.

Lip Rounding

Another aspect of vowel classification is the presence or absence of lip rounding. Some vowels, such as the vowels [o] and [u], are formed with a high degree of lip rounding. Such vowels are called rounded vowels. Some vowels, such as [i] and [ɛ], are formed without such rounding, and are called unrounded vowels.

In the next section, you will be introduced to the classification of vowels in terms of tenseness.

Tense vs. Lax

Another aspect of vowel classification is commonly characterized in terms of the tenseness or laxness of the articulators. Some vowels, such as the vowels [i] and [e], are formed with a high degree of tenseness. Such vowels are called tense vowels. Some vowels, such as  and , are formed without a high degree of tenseness, and are called lax vowels.

Some languages have a similar distinction in the articulation of vowels. This classification is in terms of the position of the tongue root. In these languages, the primary classificational feature for the vowels [i] and [e] is not that the articulators are tense, but that the root of the tongue is pushed forward, opening up the pharynx. Such a condition is known as Advanced Tongue Root (ATR). Vowels such as [ɪ] and [ɛ], on the other hand, do not have ATR in those languages that have that distinction.

Summary

In this set of lessons, you have been introduced to the classification of vowel sounds in human language. The four classifications are as follows:

  • Tongue Height

  • Tongue Backness

  • Lip Rounding

  • Tense vs. Lax

Acoustics

 
 
 
 

What is Sound, Anyway?

Sound is the result of the disturbance of air by some kind of movement. These disturbances of the air are called sound waves. Examples of the types of movement that cause this disturbance of air are the vibrations of a tuning fork, a guitar string, or a rubber band.

Let's take the guitar string as an example. The disturbance in the air is the movement of air molecules as a result of the movement of the string back and forth. When a guitar string is plucked, the string quickly moves back and forth. As it goes in one direction, the string pushes the air molecules closest to it. These air molecules then get closer to the air molecules surrounding it. This is called compression.

Here's a little note about air molecules. They prefer to be equidistant from each other. If an air molecule gets too close, the surrounding air molecules move away, attempting to reestablish the status quo.

So, when the air molecules closest to the string are compressed against the surrounding molecules, a chain reaction is set up, in which the surrounding air molecules move away from the first ones, and are then compressed against other air molecules, which then move away, and so on, and so on.

But that's not the end of it. As stated above, the guitar string moves back and forth. So, after the guitar string moves in the first direction, causing compression, it then moves in the opposite direction. As it does so, it pulls away from the surrounding air molecules. When this happens, those air molecules are now farther away from the air molecules on the other side of the string. This is called rarefaction. Since air molecules prefer to be equidistant from each other, they will move towards the molecules that are too far away. This, in turn, pulls them away from the surrounding air molecules, which then move to restablish the correct distance.

Then, the guitar string moves back again, causing compression, and the whole thing starts over again.

The following animation is an illustration of compression and rarefaction.

 

The arrow represents the movement of the guitar string, and the individual circles represent air molecules. The chain reaction through the surrounding air caused by compression and rarefaction is the sound wave.

As the guitar string vibrates at a certain number of times within a second, the surrounding air molecules within a certain distance from the string will move back and forth at that same number of times within a second.

Extracting Formant Values

Determining the formants of a vowel

A vowel's formants are the frequencies at which it resonates; that is, the frequencies which are particularly loud in an acoustic signal. Each vowel has its own set of signature formants. Vowels in different dialects also have different formant patterns. This tutorial is intended to show you how to determine vowel formants in your own speech.

Extracting formants is no simple task. It involves recording your sample and creating a spectrogram. Fortunately, there is software that allows a user to do all of these. The Language Samples Project uses Praat, a shareware product created by the linguist Paul Boersma. When using Praat, there is an intermediate step, which is to convert the recorded sample into a Praat object.

 

 

 

    • Recording your sample

    1. To analyze your speech, Praat first needs to have a sound file to work with. Choose the "Record Sound..." option under the "New" menu. This calls up the SoundRecorder window.
       

      • Make sure the Sample rate is set at 44100. The Input Source may be either External Mic (recommended) or Sound In. You will know that the program can detect your speech because the Meter will react to any sound picked up by your microphone, even if it is not recording. If you do not see colours spiking in the Meter, double check to make sure your microphone is plugged in.
         

    2. To obtain your sample, click the Record button and speak into the microphone. When you have finished, click Stop. You may listen to the recording again by clicking Play.
       

      • You may need to try more than once to get a good sample. Holding the microphone too close to your mouth will result in the signal having loud puffs and hisses. If this happens, try holding the microphone a few inches farther away.