The rules to determine the phonemic status of a sound of a complex nature (by N. Trubetskoy):
A phoneme is indivisible as no syllable division can occur within it.
A phoneme is produced by one articulatory effort.
The duration of a phoneme should not exceed that of other phonemes in the language.
Methods of phonological analysis
These rules helped to conclude that /ʧ/ and /ʤ/ in the words like cheese, each, jail, hedge are monophonemic, because these sounds are produced by one articulatory effort and no syllable division occurs within the sounds /ʧ/ and /ʤ/.
Opinions differ about the status of /tr/ and /dr/, but most phoneticions regard them as biphonemic clusters.
Idiolectal variation embraces the individual peculiarities of articulating sounds. For instance, the speaker may mumble (нечётко произносить), or lisp (say ‘thish ish’ for ‘this is’), or stutter (say a f-f-f-fine d-d-d-day)/
Idiolectal variation may cause a lot of difficulties in the communication.
