To get out of this problem, the usual solution is to say that these segments are neither vowels nor consonants but midway between the two categories. For this purpose, the term ‘semivowel’ is often used.
The idea of establishing a phonetic alphabet was first proposed by the Danish grammarian and phonetician Otto Jespersen (1860-1943) in 1886, and the first version of the International Phonetic Alphabet (the IPA chart) was published in August 1888.

Languages also frequently make use of a distinction between vowels where the quality remains constant throughout the articulation and those where there is an audible change of quality.

The categories of consonant, therefore, are established on the basis of several factors.

The manner of articulation refers to ways in which articulation can be accomplished:

Phonetics studies how speech sounds are produced, transmitted, and perceived.



Articulatory Phonetics is the study of the production of speech sounds. Acoustic Phonetics is the study of the physical properties of speech sounds. Perceptual or Auditory Phonetics is concerned with the perception of speech sounds.
Position of the vocal folds: glottal stop
1.2 The IPA

In 1886, the Phonetic Teachers’ Association was inaugurated by a small group of language teachers in France who had found the practice of phonetics useful in their teaching and wished to popularize their methods.
the articulators may close off the oral tract for an instant or a relatively long period; they may narrow the space considerably; or they may simply modify the shape of the tract by approaching each other.


The distinction between vowels and consonants lies in the obstruction of airstream. As there is no obstruction of air in the production of vowels, the description of the consonants and vowels cannot be done along the same lines.


These principles continue to be followed today.

The International Phonetic Alphabet (Revised to 2005)
2. Consonants and vowels


Consonants are produced ‘by a closure in the vocal tract, or by a narrowing which is so marked that air cannot escape without producing audible friction’. By contrast, a vowel is produced without such ‘stricture’ so that ‘air escapes in a relatively unimpeded way through the mouth or nose’.

Practically consonants may be produced at any place between the lips and the vocal folds.

Eleven places of articulation are distinguished on the IPA chart:
2.1 Consonants

In the production of consonants at least two articulators are involved.

For example, the initial sound in bad involves both lips and its final segment involves the blade (or the tip) of the tongue and the alveolar ridge.


Its main principles were that
there should be a separate letter for each distinctive sound, and that the same symbol should be used for that sound in any language in which it appears. The alphabet was to consist of as many Roman alphabet letters as possible, using new letters and diacritics only when absolutely necessary.

Phonology is the study of the sound patterns and sound systems of languages.
It aims to ‘discover the principles that govern the way sounds are organized in languages, and to explain the variations that occur’. In phonology we normally begin by analyzing an individual language, say English, in order to determine its phonological structure, i.e. which sound units are used and how they are put together. Then we compare the properties of sound systems in different languages in order to make hypotheses about the rules that underlie the use of sounds in them, and ultimately we aim to discover the rules that underlie the sound patterns of all languages.
Jones: An Outline of English Phonetics (1918)
Black: IPA Red: English

The problematic area is that the initial sound in hot gives little turbulence, depending on how forcefully it is said, and in yet and wet the initial segments are obviously vowels.





Bilabial Labiodental Dental Alveolar Postalveolar Retroflex Palatal Velar Uvular Pharyngeal Glottal
2.2 Vowels

Cardinal Vowels, as exhibited by the vowel diagram in the IPA chart, are a set of vowel qualities arbitrarily defined, fixed and unchanging, intended to provide a frame of reference for the description of the actual vowels of existing languages.