Allophonic rules

express context-dependent variation in the narrow phonetic transcription associated with a phonetic unit

Same word may have different pronunciation

• in different styles (e.g., careful vs. casual).
• in different phonetic environments

We would like to uncover general principles about how gestures are organized in a particular language (e.g., English), from which these specific rules follow as particular instances.

Ladefoged's rules related to consonant sequences:

(8)	Stops are unexploded before another stop.
(14)	Alveolar consonants become dental before dental consonants.
(15)	Alveolar stops are reduced or omitted between two consonants.
(17)	A consonant is shortened before an identical consonant.
	Not in Ladefoged:
(*)	/s/at the end of a word is sounds likewhen the next word begins with [j]

These are all special cases of a general gestural principle of organization in English:

Within a phonological phrase, oral constriction gestures for successive consonants overlap substantially. see example

Click number in left column of above table for analysis in terms of gestural scores.

 

Ladefoged's rules related to voicing

(2)	Voiceless stops are aspirated when syllable initial.
(7)	Approximants are at least partially voiceless following initial voiceless stops.
(5)	Voiceless stops are unaspirated following /s/ at the beginning of a syllable.
	Also: (not in Ladefoged)
	Voicing does not contrast after initial /s/.
	/s/ is unaspirated.

 

These are all special cases of two gestural principles:

 

• At most one laryngeal abduction gesture may occur in word-initial position in English

 

• Peak laryngeal opening is coordinated with:
  the midpoint of a fricative gesture (if any)
  the release of a stop gesture

   

  See gestural scores

Ladefoged's rules relating to consonant-vowels interactions

(18) Velar stops become more front as the following vowel in the same syllable becomes more front.

 

Gestural principle:
Consonant gestures overlap with following vowel gesture.
If consonant and vowel are specified for the same constrictor, then the effect of overlap must be blending of the targets of the two gestures.