The Classification of Sounds - Consonants and Vowels

The sounds of a language can be grouped into classes, based on the phonetic properties that they share. The most basic classification among sounds is into two main classes, namely, consonants and vowels, Consonants and vowels can be distinguished on the basis of differences in articulation. Consonants are produced or articulated with a narrow or complete closure of the vocal tract. The air-stream is either blocked momentarily or restricted so much that noise is produced as the air-stream passes the constriction. On the contrary, vowels are produced or articulated with little obstruction in the vocal tract, The difference in articulation causes consonants and vowels to differ in the way they sound. Vowels are more sonorous than consonants. This means that vowels are louder and longer lasting than consonants.

The Classification of Consonants

All consonants can be classified on the basis of (I) the place of articulation, (2) the manner of articulation and (3) the voicing or voicelessness, The place of articulation is each point at which the air-stream can be modified to produce a different sound. The manner of articulation is the modification of the lips, tongue, glottis, and velum in different ways to produce different types of sounds.

Based on the place of articulation, consonants are classified into:

a. Bilabial consonants

Bilabial consonants are consonants articulated with closure or near closer of the lips. The bilabial consonants in English are: p, b, m, and w.  

b. Labiodental consonants

Labiodental consonants are consonants articulated by the lower lip and the upper teeth. The labiodental consonants in English are: f and v.

c. Dental consonants

Dental consonants are consonants articulated by putting the tip of the tongue between the upper teeth and the lower teeth. The dental consonants in English are: θ and ð.

d. Alveolar consonants

Alveolar consonants are consonants articulated by raising the tip of the tongue against the teeth-ridge. The alveolar consonants in English are: t, d, s, z, n, l, and r.

e. Alveopalatal consonants

Alveopalatal consonants are consonants articulated by raising the blade of the tongue against the alveopalatal area, just behind the alveolar ridge. The alveopalatal consonants in English are: č j, š, and ž.

f. Palatal consonant

Palatal consonant is a consonant articulated by raising the body of the tongue against the hard palate. There is only one palatal consonant in English, that is, y.

g. Velar consonants

Velar consonants are consonants articulated by raising the back of the tongue against the soft palate. The velar consonants in English are: k, g, and ŋ.

h. Glottal consonant

Glottal consonant is a consonant articulated by adjusting the glottal opening to states other than voicing or voicelessness. There is only one glottal consonant in English, that is, h.

Based on the manner of articulation, consonants are classified as follows:

a. Stops or Plosives

Stops are made with a complete and momentary closure of the air- stream through the oral cavity, In the world's languages, stops are found at bilabial, dental, alveolar, palatal, velar, and glottal points of articulation. The stops in English are: p, b, t, d, k, and g.

b. Fricatives

Fricatives are consonants produced with a continuous air-stream through the mouth. They belong to a large class of sounds called continuants (a class that also includes vowels and glides), all of which share this property. The fricatives form a special class of continuants; during their production, they are accompanied by a continuous audible noise. The air- stream passes through a very narrow opening, resulting in turbulence, which causes the noise. The fricatives in English are: f, v, θ, ð, s, z, š, ž, and h.

c. Affricates

When a stop is released, the tongue moves rapidly away from the point of articulation. Some non-continuant consonants show a slow release of the closure; these sounds are called affricates. English has only two affricates, both of which are alveopalatals. They are heard initially in church and jump, and are transcribed as č and j respectively.

d. Nasals

Nasals are sounds produced by hindering the air-stream from the lungs in the mouth so that the air-stream cannot pass out through the mouth, and in the meantime, the velum is lowered so that the air-stream passes through the nose cavity. In English, there are only three nasals transcribed as m, n, and ŋ.

e. Liquids

Among the sounds commonly found in the word's languages are i and r and their numerous variants. They form a special class of consonants known as liquids. Liquids are continuants, but the vocal tract obstruction formed when producing them is not as great as it is for the fricative consonants. The liquids in English are: I and r.

f. Glides

A type of sound that shows properties of both consonants and vowels is called a glide. Glides may be thought of as rapidly articulated vowels; that is the auditory impression they produce. Glides are produced with an articulation like that of a vowel. However, they move quickly to another articulation, as do the initial glides in yes or wet, or quickly terminate, as do the word-final glides in boy and now.

Even though they are vowel-like in articulation, glides function as consonants. For example, glides never form the nucleus of a syllable. Since glides show properties of both consonants and vowels, it is no wonder that the terms semivowel or semiconsonant are used interchangeably with the term glide.