Quantal theory of speech

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The quantal theory of speech is a phonetic answer to one of the fundamental questions of phonology, specifically: if each language community is free to arbitrarily select a system of phonemes or segments, then why are the phoneme inventories of different languages so similar? For example, almost all languages have the stop consonants /p/, /t/, /k/, and almost all have the vowels /a/, /i/, and /u/. Other phonemes differ considerably among languages, but not nearly as much as they would if each language were free to choose arbitrarily.

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Proposed by Ken Stevens at MIT, quantal theory formalizes the intuition that some speech sounds are easier to produce than others. Sounds that are easier to reliably produce, in the formal way described below, are more common among the languages of the world; those that are harder to reliably produce are less common.

The Quantal Nature of Speech


Let Y=f(X), where X is any particular articulatory parameter (tongue tip position, for example), and Y is any particular perceptual parameter (perceived frequency of the peak in the acoustic spectrum, for example). Like any nonlinear relation, f(X) has regions of low slope (|df/dX| small) and regions of high slope (|df/dX| large). Values of Y drawn from a high-slope region are unstable, in the sense that a small change in X causes a large change in Y; values of Y drawn from a low-slope region are conversely stable, in that they are little perturbed by large changes in X. Stevens proposed in 1968 [1] that the stability of low-slope regions makes them more likely to be chosen as discrete linguistic units (phonemes) by the languages of the world, and that the distinction between any pair of phonemes tends similarly to occur across an unstable high-slope boundary region. Examples include

Consonant Place of Articulation

Consonant Manner

Vowels

Enhancement Features

Quantal theory is supported by a theory of language change, developed in collaboration with Jay Keyser, which postulates the existence of redundant or enhancement features. [6]

It is quite common, in language, to find a pair of phonemes that differ in two features simultaneously. In English, for example, "thin" and "sin" differ in both the place of articulation of the fricative (teeth versus alveolar ridge), and in its loudness (nonstrident versus strident). Similarly, "tell" and "dell" differ in both the voicing of the initial consonant, and in its aspiration (the /t/ in "tell" is immediately followed by a puff of air, like a short /h/ between the plosive and the vowel). In many cases, native speakers have strong and mistaken intuition about the relative importance of the two distinctions, e.g., speakers of English believe that "thin" versus "sin" is a place of articulation difference, even though the loudness difference is more perceptible. Stevens, Keyser and Kawasaki [7] proposed that such redundant features evolve as an enhancement [6] of an otherwise weak acoustic distinction, in order to improve the robustness of the language's phonological system.

Related Research Articles

Approximants are speech sounds that involve the articulators approaching each other but not narrowly enough nor with enough articulatory precision to create turbulent airflow. Therefore, approximants fall between fricatives, which do produce a turbulent airstream, and vowels, which produce no turbulence. This class is composed of sounds like and semivowels like and, as well as lateral approximants like.

In articulatory phonetics, a consonant is a speech sound that is articulated with complete or partial closure of the vocal tract. Examples are and [b], pronounced with the lips; and [d], pronounced with the front of the tongue; and [g], pronounced with the back of the tongue;, pronounced in the throat;, [v], and, pronounced by forcing air through a narrow channel (fricatives); and and, which have air flowing through the nose (nasals). Contrasting with consonants are vowels.

A fricative is a consonant produced by forcing air through a narrow channel made by placing two articulators close together. These may be the lower lip against the upper teeth, in the case of ; the back of the tongue against the soft palate in the case of German ; or the side of the tongue against the molars, in the case of Welsh. This turbulent airflow is called frication.

<span class="mw-page-title-main">International Phonetic Alphabet</span> System of phonetic notation

The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standardized representation of speech sounds in written form. The IPA is used by lexicographers, foreign language students and teachers, linguists, speech–language pathologists, singers, actors, constructed language creators, and translators.

A lateral is a consonant in which the airstream proceeds along one or both of the sides of the tongue, but it is blocked by the tongue from going through the middle of the mouth. An example of a lateral consonant is the English L, as in Larry. Lateral consonants contrast with central consonants, in which the airstream flows through the center of the mouth.

<span class="mw-page-title-main">Manner of articulation</span> Configuration and interaction of the articulators when making a speech sound

In articulatory phonetics, the manner of articulation is the configuration and interaction of the articulators when making a speech sound. One parameter of manner is stricture, that is, how closely the speech organs approach one another. Others include those involved in the r-like sounds, and the sibilancy of fricatives.

<span class="mw-page-title-main">Phonetics</span> Branch of linguistics that comprises the study of the sounds of human language

Phonetics is a branch of linguistics that studies how humans produce and perceive sounds, or in the case of sign languages, the equivalent aspects of sign. Linguists who specialize in studying the physical properties of speech are phoneticians. The field of phonetics is traditionally divided into three sub-disciplines based on the research questions involved such as how humans plan and execute movements to produce speech, how various movements affect the properties of the resulting sound, or how humans convert sound waves to linguistic information. Traditionally, the minimal linguistic unit of phonetics is the phone—a speech sound in a language which differs from the phonological unit of phoneme; the phoneme is an abstract categorization of phones, and it is also defined as the smallest unit that discerns meaning between sounds in any given language.

In phonetics, rhotic consonants, or "R-like" sounds, are liquid consonants that are traditionally represented orthographically by symbols derived from the Greek letter rho, including ⟨R⟩, ⟨r⟩ in the Latin script and ⟨Р⟩, ⟨p⟩ in the Cyrillic script. They are transcribed in the International Phonetic Alphabet by upper- or lower-case variants of Roman ⟨R⟩, ⟨r⟩: r, ɾ, ɹ, ɻ, ʀ, ʁ, ɽ, and ɺ. Transcriptions for vocalic or semivocalic realisations of underlying rhotics include the ə̯ and ɐ̯.

The field of articulatory phonetics is a subfield of phonetics that studies articulation and ways that humans produce speech. Articulatory phoneticians explain how humans produce speech sounds via the interaction of different physiological structures. Generally, articulatory phonetics is concerned with the transformation of aerodynamic energy into acoustic energy. Aerodynamic energy refers to the airflow through the vocal tract. Its potential form is air pressure; its kinetic form is the actual dynamic airflow. Acoustic energy is variation in the air pressure that can be represented as sound waves, which are then perceived by the human auditory system as sound.

Sibilants are fricative consonants of higher amplitude and pitch, made by directing a stream of air with the tongue towards the teeth. Examples of sibilants are the consonants at the beginning of the English words sip, zip, ship, and genre. The symbols in the International Phonetic Alphabet used to denote the sibilant sounds in these words are, respectively,. Sibilants have a characteristically intense sound, which accounts for their paralinguistic use in getting one's attention.

In phonetics, palatalization or palatization is a way of pronouncing a consonant in which part of the tongue is moved close to the hard palate. Consonants pronounced this way are said to be palatalized and are transcribed in the International Phonetic Alphabet by affixing the letter ⟨ʲ⟩ to the base consonant. Palatalization cannot minimally distinguish words in most dialects of English, but it may do so in languages such as Russian, Japanese, Norwegian (dialects), Võro, Irish and Kashmiri.

<span class="mw-page-title-main">Retroflex consonant</span> Type of consonant articulation

A retroflex, apico-domal, or cacuminalconsonant is a coronal consonant where the tongue has a flat, concave, or even curled shape, and is articulated between the alveolar ridge and the hard palate. They are sometimes referred to as cerebral consonants—especially in Indology.

<span class="mw-page-title-main">Voiced palatal plosive</span> Consonantal sound represented by ⟨ɟ⟩ in IPA

The voiced palatal plosive or stop is a type of consonantal sound in some vocal languages. The symbol in the International Phonetic Alphabet that represents this sound is ɟ, a barred dotless ⟨j⟩ that was initially created by turning the type for a lowercase letter ⟨f⟩. The equivalent X-SAMPA symbol is J\.

The voiceless palatal plosive or stop is a type of consonantal sound used in some vocal languages. The symbol in the International Phonetic Alphabet that represents this sound is c, and the equivalent X-SAMPA symbol is c.

A voiceless postalveolar fricative is a type of consonantal sound used in some spoken languages. The International Phonetic Association uses the term voiceless postalveolar fricative only for the sound, but it also describes the voiceless postalveolar non-sibilant fricative, for which there are significant perceptual differences.

Linguolabials or apicolabials are consonants articulated by placing the tongue tip or blade against the upper lip, which is drawn downward to meet the tongue. They represent one extreme of a coronal articulatory continuum which extends from linguolabial to subapical palatal places of articulation. Cross-linguistically, linguolabial consonants are very rare. They are found in a cluster of languages in Vanuatu, in the Kajoko dialect of Bijago in Guinea-Bissau, in Umotína, and as paralinguistic sounds elsewhere. They are also relatively common in disordered speech, and the diacritic is specifically provided for in the extensions to the IPA.

<span class="mw-page-title-main">Laminal consonant</span> Phone (speech sound)

A laminal consonant is a phone produced by obstructing the air passage with the blade of the tongue, the flat top front surface just behind the tip of the tongue in contact with upper lip, teeth, alveolar ridge, to possibly, as far back as the prepalatal arch, although in the last contact may involve parts behind the blade as well. It is distinct from an apical consonant, produced by creating an obstruction with the tongue apex only. Sometimes laminal is used exclusively for an articulation that involves only the blade of the tongue with the tip being lowered and apicolaminal for an articulation that involves both the blade of the tongue and the raised tongue tip. The distinction applies only to coronal consonants, which use the front of the tongue.

<span class="mw-page-title-main">Voiceless palatal lateral fricative</span> Consonantal sound represented by ⟨𝼆⟩ or ⟨ʎ̝̊⟩ in IPA

The voiceless palatal lateral fricative is a type of consonantal sound, used in a few spoken languages.

In phonetics, secondary articulation occurs when the articulation of a consonant is equivalent to the combined articulations of two or three simpler consonants, at least one of which is an approximant. The secondary articulation of such co-articulated consonants is the approximant-like articulation. It "colors" the primary articulation rather than obscuring it. Maledo (2011) defines secondary articulation as the superimposition of lesser stricture upon a primary articulation.

References

  1. K.N. Stevens (1968). The quantal nature of speech: evidence from articulatory-acoustic data.
  2. "Acoustical Society of America Gold Medal Award, 1995: Kenneth N. Stevens". Archived from the original on 2007-06-27. Retrieved 2013-07-04.
  3. K.N. Stevens (1971). ""Airflow and Turbulence Noise for Fricative and Stop Consonants: Static Considerations," J. Acoust. Soc. Am. 50(4):1180-1192".
  4. 1 2 K.N. Stevens (1987). "Relational Properties as Perceptual Correlates of Phonetic Features," Proc. Eleventh Int. Conf. Phonetic Sciences (ICPhS) 4:352-356.
  5. I. Lehiste and G.E. Peterson (1961). ""Transitions, Glides, and Diphthongs," J. Acoust. Soc. Am. 33(3):268-277".
  6. 1 2 K.N. Stevens and S.J. Keyser (1989). ""Primary Features and their Enhancement in Consonants," Language 65(1):81-106". Language. 65 (1): 81–106. doi:10.2307/414843. JSTOR   414843.
  7. K.N. Stevens and S.J. Keyser and H. Kawasaki (1986). "Toward a Phonetic and Phonological Theory of Redundant Features," in "Invariance and Variability in Speech Processes," Lawrence Erlbaum Associates, pp. 426-463. Lawrence Erlbaum Associates. ISBN   9780898595451.