32. Articulatory transitions of vowel and cons phonemes.

In the process of speech, that is in the process of transition from the articulatory work of one sound to the articulatory work of the neighbour­ing one, sounds are modified. These modifications can be conditioned:

a) by the complementary distribution of phonemes, e. g. the fully back /u:/ becomes back-advanced under the influence of the preceding mediolingual sonorant /j/ in the words tune, nude. In the word keen /k/ is not so back as its principal variant, it is ad­vanced under (be influence of the fully front /i;/ which follows it:

b) by the contextual variations in which phonemes may occur at the junction of words, e. g. the alveolar phoneme /n/ in the combination in the is assimilated to the dental variant under the influence of /ð/ which follows it;

c) by the style of speech: official or rapid colloquial. E. g. hot muffinsmay turn into

Assimilation is a modification of a consonant under the influence of a neighbouring consonant. When a consonant is modified under the influence of an adjacent vow­el or vice versa this phenomenon is called adaptation or accommodation, e. g. tune, keen, lea, cool.

When one of the neighbouring sounds is not realized in rapid or care­less speech this process is called elision, e. g. a box of matches may be pronounced without _[v].

Assimilation which occurs in everyday speech in the present-day pro­nunciation is called living. Assimilation which took place at an earlier stage in the history of the language is called historical.

Assimilation can be:

1progressive, when the first of the two sounds affected by assimila­tion makes the second sound similar to itself, e. g. in desks the sounds /k/ make the plural inflection s similar to the voiceless /k/.

2regressive, when the second of the two sounds affected by assimi­lation makes the first sound similar to itself, e. g. in the combination at the the alveolar /t/ becomes dental, assimilated to the interdental / ð / which follows it;

3double, when the two adjacent sounds influence each other, e.g. twice /t/ is rounded under the influence of /w/ and /w/ is partly devoiced under (he influence of the voiceless /t/.

When the two neighbouring sounds arc affected by assimilation, it may influence: 1) the work of the vocal cords; 2) the active organ of speech; 3) the manner of noise production; 4) both: the place of articula­tion and the manner of noise production.

l)Assimilation affecting the work of the vocal cords is observed when one of the two adjacent соседний consonants; becomes voiced under the influence of the neighbouring voiced consonant, or voiceless — under the influ­ence of the neighbouring voiceless consonant.

In the process of speech the sonorants /m, n, 1, r; j, w/ are partly devoiced before a vowel, preceded by the voiceless consonant phonemes /s, p, t, k/, e. g. plate, slowly, twice, ay. This assimilation is not observed in the most careful styles of speech.

2) The manner of noise production is affected by assimilation in cas­es of a) lateral plosion and b) loss of plosion or incomplete plosion. The lateral plosion takes place, when a plosive is followed by /1/. In this case the closure for the plosive is not released till the off-glide for the second [l]. Incomplete plosion takes place in the clusters a) of two similar plosives like /pp,pb, tt, td, kk, kg/, or b) of two plosives with different points of articulation like:/kt/,/dg/, /db/, /tb/. So there is only one explosion for the two plosives.

3) Assimilation affects the place of articulation and the manner of noise production when the plosive, alveolar /tl is followed by the post-alveolar /r/. For example, in the word trip alveolar 1t1 be­comes post-alveolar and has a fricative release.