The present paper deals with the synchronic variation of the phoneme /ʁ/ in the unstressed word final syllable onset in modern German spontaneous speech. Our research task was to determine the phonetic context, in which the phoneme /ʁ/ undergoes modifications in the above-mentioned position and to establish, whether the intensity and the type of modifications (vocalization or elision of the phoneme /ʁ/) could correlate with the part of speech and with the combinatorial conditions of sound realization. The data collected are based on the acoustic analysis of spontaneous speech (interviews in the media) of 20 German scientists (10 men and 10 women) from the Central and Southern Germany. Our results showed that the phoneme /ʁ/ undergoes intense modifications mainly in the word final position "stressed long vowel + ʁ + schwa vowel + nasal" in various parts of speech: verbs, plural forms of nouns, adjectives, participles, substantivized verbs, possessive pronouns and prepositions.
The type of modification of the phoneme /ʁ/ in the relevant position correlates with the sound context. After high and mid vowels [iː], [yː], [uː], [eː], [ɛː], [øː], [oː] vowel realizations as unsyllabic [ɐ̯] clearly dominate over the consonantal as [ʁ], leading to the emergence of centralizing secondary diphthongs [iːɐ̯], [yːɐ̯], [uːɐ̯], [eːɐ̯], [ɛːɐ̯], [øːɐ̯], [oːɐ̯]. In the position after the long [aː] an elision of the allophones of the phoneme /ʁ/ is predominant, which can lead to an overlong articulation of the preceding low vowel as [aːː].