Neutralization
We have seen
the case of one mental sound having two mouth pronunciations, repeated here:
|
Memory: |
|
/æ/ |
|
|
Mouth: |
[æ̃] |
|
[æ] |
It is also
possible to have the situation where sound that are memorized differently are
nevertheless pronounced identically under certain circumstances. Consider the
pronuncation of the vowels in these two words:
[tɛləgræf]
"telegraph"
[təlɛgrəfi]
"telegraphy"
But since
both of these words involve the same morpheme, meaning "telegraph",
this morpheme must have the same memorized representation, namely,
/tɛlɛgræf/
Therefore
the changes in pronunciation are insignificant for memory here, and must be due
to a rule of pronunciation. The rules is very simple, unstressed vowels reduce
to schwa in English.
[vowel,
unstressed] → [ə]
[vowel,
unstressed] → [mid, central, unrounded, plain]
This means
that in this case we have two different sounds as far as the mind goes, and yet
when unstressed, only one pronunciation:
|
Mind: |
/æ/ |
|
/ɛ/ |
|
Mouth: |
|
[ə] |
|
The
pronunciation of the English plural
The plural
marker in English has several different pronuncations:
[∅] (zero): [dir], [ʃip], [fɪʃ],
etc.
[ə̃n]: [ɑksə̃n], etc.
[s]: [kæts], [pɑts], [sæks], etc.
[z]: [dɑgz], [rɪbz], [bænz], etc.
[əz]:
[bʊʃəz], [rozəz], etc.
The choice
of zero or [ə̃n] is handled in the Morphology, because it is not
predictable from the speech sounds. The choice of [s], [z] or [əz] is
handled in the Phonology, because it is predictable from the speech sounds.
So we need
to figure out what conditions the appearance of the various pronunciations of
the plural. Where do we get which pronunciations?
Pronunciations: [s]
[z] [əz]
Examples: cats dads bushes
beliefs
sleeves roses
cups cabs kisses
tacks tags churches
paths wreathes judges
dams
cans
songs
fears
peels
bees
bays
boos
bows
boys
We want to
predict the pronunciations, so we need to pick one of the pronunciations to be
stored in memory. We should pick the least predictable one to store in memory,
here [z]. Therefore, the memorized representation for the plural morpheme is
/z/.
Now we need
to write rules to get the other pronunciations.
What is
similar about all the stems in the first column, the ones that take [s] in the
plural? They are end in voiceless sounds! So the rule for these must be:
/z/ becomes
[s] when it comes after a voiceless sound
But we can
do better than this. What is the difference between /z/ and [s]? /z/ is
[voiced] and [s] is [voiceless]. So we can write the rule as:
/z/ becomes
[voiceless] when it comes after a [voiceless] sound
/z/ → [voiceless]
/ [voiceless] _
Thus, this
is a rule of assimilation.
What is the
characteristic shared by the words in the third column, where they say
[əz] for the plural? All of these words end in sibilant (see FRH p. 300)
sounds. So we can write the rule:
Insert
[ə] in between a sibilant and /z/
Again, we
can ask if we can do better. Is /z/ sibilant? Yes! So we can write the rule:
Insert
[ə] inbetween two sibilants
∅
→ [ə] / [sibilant] __ [sibilant]
The use of
the zero here for "no sound" or "nothing" is similar to the
concept of zero morphemes. For insertion, ∅ → something; for
deletion, something → ∅.
(Idsardi)
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