Here, with additional context, are the audio clips from yesterday's post "The phonetics of a#n vs. an# juncture":
The answers in the comments were about 73% correct overall. It's not easy to count, since many people didn't obey the "forced choice" constraints, but here's a breakdown by item, counting "I can't tell" and similar answers as half a vote for each alternative:
|an ice||a nice|
The audio clips came from the "Fisher" collection of telephone conversations, published by the LDC in two parts in 2004 and 2005. In the collection's transcripts, there were 53 instances of "an ice" and 1726 of "a nice", from which I selected two of each at random.
The overall tally of 73% correct is consistent with the "two thirds" cited by Bob Ladd from Ladd and Schepman, "'Sagging transitions' between high pitch accents in English: experimental evidence", J. Phonetics 31(1) 2003.
Our little "experiment" here was flawed in various ways that make the exact numbers not worth interpreting —
- there were too few test items, given the usual item-by-item variability;
- the context was missing (though it could not easily have been included without giving the answers away);
- the "subjects" saw one another's answers;
- some of the "subjects" were non-native speakers;
But the general pattern is consistent with what such experiments generally show, which is that ordinary speech contains probabilistic clues about junctural ambiguities, and people are pretty good about interpreting these cues, but most exemplars nevertheless remain ambiguous to some extent.
In such experiments, attention is typically focused in advance on the ambiguity to be resolved, to the exclusion of other cognitive tasks. The results therefore tend to show somewhat better performance than when people hear the same sort of material performed in a context where either interpretation is plausible, and where the judgment needs to be made on the fly, in the course of ordinary speech understanding.
In that case, the individual listener's in-context bias towards one interpretation or the other is likely to play a much larger role. And if the listeners are equally disposed to hear either alternative, they're like to recognize that in fact they can't tell what the speaker meant to say. Which is exactly as it should be, from a communicative point of view.
By the way, this small sample also confirms Bob's citation of Lehiste's observation about [n] duration — we expect [n] in V#n'V to be generally longer than [n] in Vn#'V, given that the onset of stressed syllables is the strongest position for consonants in general, while the context V__#V is a very weak one (as shown by the fact that flapping and voicing occurs, in American English, in sequences like "at all" or "Fat Albert").
Specifically, I measure the following durations in milliseconds for the nasal murmurs in question:
FWIW, this gives us averages of 57 msec. for the [n] in "a nice", vs. 38.5 msec. for the [n] in "an ice". These are a considerably shorter overall that the 67 and 47 msec. that Bob quoted from his 2003 paper. This is expected given the differences in linguistic and communicative context; but the direction of the effect is the same.
Note also that the ranges (in this tiny sample) overlap, consistent with my previous suggestion that the within-category variation would be roughly as large as the average between-category difference.