Is there any difference between the two diphthongs in English IPA transcriptions?
If I search a word in the Cambridge dictionary, it gives /aɪ/ for both UK English and US English.
For example, the word "night" is transcribed as /naɪt/ in Cambridge English dictionary for both UK and US English.
But Lexico (powered by Oxford) gives /nʌɪt/ for "night".
In Cambridge dictionary, I can hear a slight difference between UK and US pronunciation but the IPA symbols are the same.
Dictionary.com also has /aɪ/.
Is there any difference between them? Or can I use /ʌɪ/ and /aɪ/ interchangeably?
Best Answer
The notations /ʌɪ/ and /ɑɪ/ represent a contrastive phonemic difference that some native speakers of English produce and perceive between certain minimal pairs.
For those speakers, the following are minimal pairs differing only in that the first word has the /ʌɪ/ phoneme but the second word has the /ɑɪ/ phoneme:
Because those are minimal pairs for those speakers, that proves that for them, /ʌɪ/ versus /ɑɪ/ is a phonemic distinction not merely a phonetic one, because changing the sound changes the word in their minds.
This is the phenomenon that has generally come to be known as Canadian raising but it is by no means strictly Canadian. Most native speakers throughout North America make this phonemic distinction, as do some from Northern Ireland.
For such speakers, the raised diphthong /ʌɪ/ occurs in such words as tight, dice, mice, ice, bison, writer, spider, tiger, kind, hire, fire, tire, dire, mire, lyre, bier, sire, shire, choir, pliers, Ireland, inquire, entire, expire, idle, ˈhigh school. However, not all such speakers necessarily have the raised variant in all those terms just listed.
Similarly, for those speakers with this phonemic contrast, the unraised diphthong /ɑɪ/ is (often) found in such words as dyed, dyes, dyer, ire, ion, dine, pine, bind, buys, prize, surmise, rider, scythe, horizon, higher, sigher, shyer, buyer, liar, denier, Oscar Mayer, idol, high ˈschool.
However, if you are referring to allophonic phonetic renditions for the same pair of phonemes, then this requires narrow phonetic transcriptions with complex notation that only specialists are apt to understand.
If so, then the /ʌɪ/ phoneme of ice can variously — depending on the speaker, region, and utterance — be any of [ʌɪ], [ʌ̈ɪ], [äɪ], [ɑ̟i], [äɛ̝̈], [ɐi], [ɐɪ], [ə̠i], [ɛ̈i].
Here are the technical decoded details of what each of those phonetic allophones of the /ʌɪ/ phoneme means:
Compare that set with phonetic realizations of the /ɑɪ/ phoneme of nine, which can be any of [ɑɪ], [ɑˑɪ], [äɪ], [ɑ̈ˑɪ], [ɑ̈ˑɪ̠], [ɑ̟ˑɪ], [äˑɐ], [äˑe̞], [äˑɛ̝̈], [äˑi], [äˑɪ], [ɐˑiˑ], [ɐ̟ˑɪ̠], [ɐˑɪˑ], [ɐi], [ɐiˑ], [ɐɪ], [æˑi], [ɛ̈ˑiˑ], [ɛ̈ĭɪ̠], [ɜ̟ˑiˑ], [ɔ̟ɪ], [ʌ̈ɪ], [ə̟ɪ̝].
Here are the technical decoded details of what each of those phonetic allophones of the /ɑɪ/ phoneme means:
However, for speakers who have merges in minimal pairs like hire–higher, you should not use different phonemes since those speakers do not make such a distinction.
Dictionaries do not try to represent narrow phonetics. They present broad phonemic transcriptions, virtually always choosing just one of either /ʌɪ/ or /ɑɪ/, and then pretending that everyone says only that version, belying the existence of minimal pairs.