Posted by Neal on April 11, 2014
Glen emailed me a week or so ago:
Do you sometimes feel like people pronounce “united” to sound like “unined”? (Three syllables, but replacing the t sound with an n sound.) If so, is there some principle that would explain it?
In fact, I have heard this. It’s particularly noticeable in the Stuff They Don’t Want You to Know podcast. However, instead of [n], Glen may have been hearing the nasalized alveolar tap [ɾ̃]. (I have enlarged the font to make the diacritic visible.) The non-nasalized alveolar tap [ɾ] is the voiced, /d/-like sound that you hear in American English in words like atom and writer. As for the nasalized version, just as [p] and [b] have a nasal counterpart [m]; and [t] and [d] have a nasal counterpart [n]; and [k] and [g] have a nasal counterpart [ŋ]; the alveolar tap [ɾ] has a nasal counterpart. But there isn’t a special IPA character for it; instead, we just make do by putting a nasalization tilde above the tap symbol: [ ɾ̃].
You may notice that there’s something missing from this picture. [m] corresponds to two both a voiceless and a voiced non-nasal consonant, [p] and [b]; [n] to [t] and [d]; and [ŋ] to [k] and [g]; but [ɾ̃] corresponds only to the voiced [ɾ].
Or does it? It turns out that a voiceless alveolar tap is possible, as I learned on John Wells’ Phonetics Blog. You devoice it the same as you devoice any other consonant: by not letting your vocal folds vibrate while you say it. It’s just that taps happen so much faster than other consonants that it never occurred to me that this was possible. Again, there’s no special IPA symbol for it; instead, we write it by putting a “voiceless” diacritic under the tap symbol: [ɾ̥].
Moving to the second part of Glen’s question, I would call the [jũnɑɪ̃ɾ̃̃əd] pronunciation of united a progressive assimilation, because the nasal quality of the first /n/ persists, turning the subsequent alveolar tap into [ɾ̃]. As for why it persists, I guess it does because it can. We don’t distinguish between ordinary and nasalized alveolar taps, nor between nasalized alveolar taps and /n/. Furthermore, there’s little danger of a speaker hearing it as /n/, because if it were actually an /n/ before the suffix -ed, we’d only have two syllables: [jũnɑɪ̃nd].
If it’s just the nasality of the /n/ that’s causing the assimilation of the tap, we should expect it to happen with other nasal consonants, too. For example, you would expect that people might also realize the /t/ or /d/ as [ɾ̃] in words or phrases like mated or outmoded, hang it up or ring it up. Maybe I have, but if so, I’ve never noticed it the way I’ve been noticing “you-nine-ed.” Have you?