Modifications of sounds in English

Sounds in actual speech are seldom pronounced by themselves. To pronounce a word consisting of more than one sound, it is necessary to join the sounds together in the proper way. There exist several types of junction, some of which are common to all or many languages, while others are characteristic of individual languages. In order to master these specific types of junction it is necessary to understand the mechanism of joining sounds together. This mechanism can only be understood after analyzing the stages in the articulation of a speech-sound pronounced in isolation.
Every speech-sound pronounced in isolation has three stages of articulation. They are (1) the on-glide, or the initial stage, (2) the retention-stage, or the medial stage, and (3) the off-glide (release), or the final stage.
The on-glide, or the beginning of a sound, is the stage during which the organs of speech move away from a neutral position to lake up the position necessary for the pronunciation of a consonant or a vowel. The on-glide produces no audible sound. The retention-stage or the middle of a sound is the stage during which the organs of speech are kept for some time either in the same position necessary to pronounce the sound (in the case of non-complex sounds) or move from one position to another (within complex sounds, such as diphthongoids, diphthongs and affricates). For the retention-stage of a stop consonant the term stop-stage may also be used. The off-glide, or the end of a sound, is the stage during which the organs of speech move away to a neutral position. The off-glide of most sounds is not audible, the exception being plosives whose off-glide produces the sound of plosion before a vowel and in a word-final position before a pause.
In English there are two principal ways of linking two adjacent speech sounds: I. Merging of stages. II. Interpenetration of stages. The type of junction depends on the nature of the sounds that are joined together. As all English sounds come under the classification of consonants and vowels we may speak of joining:
(a) a consonant to a following vowel (C + V), as in the word [mi:] me;
(b) a vowel to a following consonant (V + C), as in the word [σn] on;
(c) two consonants (C + C), as in the word [bləυ] blow:
(d) two vowels (V + V), as in the word [riæləti] reality.
Merging of stages, as compared with interpenetration of stages, is a simpler and looser way of joining sounds together. It usually takes place if two adjacent sounds of a different nature are joined together. In this case the end of the preceding sound penetrates into the beginning of the following sound. In other words, the end of the first sound and the beginning of the second are articulated almost simultaneously. Interpenetration of stages usually takes place when consonants of a similar or identical nature are joined. In this case the end of the first sound penetrates not only into the beginning but also into the middle part of the second sound, as in [ækt] act, [begd] begged.
The modifications are observed both within words and word boundaries. There are the following types of modification: assimilation, accommodation, reduction, elision, and inserting. The adaptive modification of a consonant by a neighbouring consonant in a speech chain is assimilation. Accommodation is used to denote the interchanges of VC or CV types. Reduction is actually qualitative or quantitative weakening of vowels in unstressed positions. Elision is a complete loss of sounds, both vowels and consonants. Inserting is a process of sound addition.
MODIFICATIONS OF CONSONANTS

1. Assimilation
1.1. Place of articulation
• t, d > dental before [ð, θ]: eighth, at the, said that
• t, d > post-alveolar before [r]: tree, true, dream, the third room
• s, z > post-alveolar before [∫]: this shop, does she
• t, d > affricates before [j]: graduate, could you
• m > labio-dental before [f]: symphony
• n > dental before [θ]: seventh
• n > velar before [k]: thank
1.2. Manner of articulation
• loss of plosion: glad to see you, great trouble
• nasal plosion: sudden, at night, let me see
• lateral plosion: settle, at last
1.3. Work of the vocal cords
• voiced > voiceless: newspaper, gooseberry (and in grammatical …)
has, is, does > [s]; of, have > [f]
Notice: In English typical assimilation is voiced > voiceless; voiceless > voiced is not typical.
1.4. Degree of noise
• sonorants > are partially devoiced after [p, t, k, s]
2. Accommodation
2.1. Lip position
• consonant + back vowel: pool, rude, who (rounded)
• consonant + front vowel: tea, sit, keep (spread)
3. Elision
3.1. Loss of [h] in personal and possessive pronouns and the forms of the auxiliary verb have.
3.2. [l] lends to be lost when preceded by [o:]: always, already, all right
3.3. In cluster of consonants: next day, just one. mashed potatoes
4. Inserting of sounds
4.1. Linking [r] (potential pronunciation of [r]): car owner
4.2. Intrusive [r]: [r] is pronounced where no r is seen in the spelling china and glass: it is not recommended to foreign learners.


MODIFICATION OF VOWELS
1. Reduction
1.1. Quantitative
1.2. Qualitative
2. Accommodation
2.2 Positional length of vowels: knee - need - neat
2.3. Nasalization of vowels: preceded or followed by [n, m]: never, then, men